What amount of dioxygen(in gram) contains 1.8 x 10²² molecules?
🥳 Wohoo! Correct answer
Mass = (n/Nₐ) x M.
Use Avogadro’s number to calculate the mass of dioxygen.
(1.8 x 10²² / 6.022 x 10²³) x 32 g/mol = 0.960 g.
The weight of dioxygen for given molecules is 0.960 g.
Misapplying Avogadro’s number or molar mass in calculations.
😢 Uh oh! Incorrect answer, Try again
Carefully substitute values into Avogadro’s relationship.
Mass = (n/Nₐ) x M.
Use Avogadro’s number to calculate the mass of dioxygen.
(1.8 x 10²² / 6.022 x 10²³) x 32 g/mol = 0.960 g.
The weight of dioxygen for given molecules is 0.960 g.
Misapplying Avogadro’s number or molar mass in calculations.
Which of the following conversions involves a change in hybridization and geometry?
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Geometry ∝ Hybridization changes.
Hybridization changes from sp² to sp³ in BF₃ to BF₄⁻ conversion.
BF₃ is trigonal planar, BF₄⁻ is tetrahedral due to lone pair addition.
Final result: Geometry change = BF₃ to BF₄⁻.
Overlooking hybridization changes in ion formation.
😢 Uh oh! Incorrect answer, Try again
Identify lone pair effects on hybridization and geometry.
Geometry ∝ Hybridization changes.
Hybridization changes from sp² to sp³ in BF₃ to BF₄⁻ conversion.
BF₃ is trigonal planar, BF₄⁻ is tetrahedral due to lone pair addition.
Final result: Geometry change = BF₃ to BF₄⁻.
Overlooking hybridization changes in ion formation.
In presence of HCl, H₂S results in precipitation of Group-2 elements but not Group-4 because...
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H₂S dissociation ∝ pH and sulfide ion concentration.
H₂S dissociation depends on pH, affecting S²⁻ concentration for precipitation.
Group-2 sulfides form under low S²⁻ concentrations due to lower solubility products.
Final result: Precipitation due to lower S²⁻ concentration.
Miscalculating S²⁻ concentration effect on precipitation.
😢 Uh oh! Incorrect answer, Try again
Relate solubility products to sulfide precipitation in acidic media.
H₂S dissociation ∝ pH and sulfide ion concentration.
H₂S dissociation depends on pH, affecting S²⁻ concentration for precipitation.
Group-2 sulfides form under low S²⁻ concentrations due to lower solubility products.
Final result: Precipitation due to lower S²⁻ concentration.
Miscalculating S²⁻ concentration effect on precipitation.
The pair of compounds which cannot exist together in solution is
🥳 Wohoo! Correct answer
Reaction: NaHCO₃ + NaOH → Na₂CO₃ + H₂O.
Identify incompatible compounds in solution.
NaHCO₃ reacts with NaOH to form Na₂CO₃ and water.
Acid-base reaction prevents coexistence.
Forgetting that NaHCO₃ and NaOH react in solution.
😢 Uh oh! Incorrect answer, Try again
Look for acid-base pairs that react with each other.
Reaction: NaHCO₃ + NaOH → Na₂CO₃ + H₂O.
Identify incompatible compounds in solution.
NaHCO₃ reacts with NaOH to form Na₂CO₃ and water.
Acid-base reaction prevents coexistence.
Forgetting that NaHCO₃ and NaOH react in solution.
The two electrons have quantum numbers P: 3, 2, -2, +½; Q: 3, 0, 0, +½. Which of the following statement is true?
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Energy ∝ (n + l); Higher (n + l) → Higher energy.
Energy depends on (n + l); higher (n + l) means higher energy.
Calculate (n + l): P = 3 + 2 = 5, Q = 3 + 0 = 3; P > Q in energy.
Final result: P has greater energy than Q.
Miscomputing energy by ignoring (n + l) rule.
😢 Uh oh! Incorrect answer, Try again
Carefully apply (n + l) rule to compare orbital energies.
Energy ∝ (n + l); Higher (n + l) → Higher energy.
Energy depends on (n + l); higher (n + l) means higher energy.
Calculate (n + l): P = 3 + 2 = 5, Q = 3 + 0 = 3; P > Q in energy.
Final result: P has greater energy than Q.
Miscomputing energy by ignoring (n + l) rule.
Successive ionization enthalpies(in KJ/mol) for an element are 577.5, 1810, 2750, 11,580, 14,820. Identify the element.
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Ionization energy trends for elements.
Sudden jump after the third ionization energy indicates stability of the configuration after removal of 3 electrons.
Element has 3 valence electrons; hence it is Aluminium (Al).
Final result: Element = Aluminium (Al).
Misinterpreting jumps in ionization enthalpy data.
😢 Uh oh! Incorrect answer, Try again
Analyze jumps in successive ionization energies to identify stable states.
Ionization energy trends for elements.
Sudden jump after the third ionization energy indicates stability of the configuration after removal of 3 electrons.
Element has 3 valence electrons; hence it is Aluminium (Al).
Final result: Element = Aluminium (Al).
Misinterpreting jumps in ionization enthalpy data.
The salt which responds to dilute and concentrated H₂SO₄ is...
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Ba(NO₃)₂ + H₂SO₄ → BaSO₄.
Ba(NO₃)₂ reacts with both dilute and concentrated H₂SO₄ to form BaSO₄ precipitate.
Reaction: Ba(NO₃)₂ + H₂SO₄ → BaSO₄ + 2HNO₃.
Final result: Ba(NO₃)₂ responds to dilute and concentrated H₂SO₄.
Forgetting the reaction conditions with dilute/conc. H₂SO₄.
😢 Uh oh! Incorrect answer, Try again
Identify precipitate-forming salts with dilute/conc. H₂SO₄.
Ba(NO₃)₂ + H₂SO₄ → BaSO₄.
Ba(NO₃)₂ reacts with both dilute and concentrated H₂SO₄ to form BaSO₄ precipitate.
Reaction: Ba(NO₃)₂ + H₂SO₄ → BaSO₄ + 2HNO₃.
Final result: Ba(NO₃)₂ responds to dilute and concentrated H₂SO₄.
Forgetting the reaction conditions with dilute/conc. H₂SO₄.
HCl gas is covalent and NaCl is an ionic compound. This is because
🥳 Wohoo! Correct answer
ΔEN=ENᵡ-ENᵧ
Calculate electronegativity difference: ΔEN(HCl)=1.0, ΔEN(NaCl)=2.1
Apply Pauling's rule: ΔEN<2.1 → covalent
Compare bond types based on ΔEN
Not considering ΔEN threshold
😢 Uh oh! Incorrect answer, Try again
Consider electronegativity difference
ΔEN=ENᵡ-ENᵧ
Calculate electronegativity difference: ΔEN(HCl)=1.0, ΔEN(NaCl)=2.1
Apply Pauling's rule: ΔEN<2.1 → covalent
Compare bond types based on ΔEN
Not considering ΔEN threshold
An organic compound contains C = 40%, H = 13.33% and N = 46.67%. Its empirical formula is
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Empirical formula calculations
Calculate moles of each element: C(3.33), H(13.33), N(3.33)
Find simplest whole number ratio
Determine empirical formula: CH₄N
Wrong atomic mass usage
😢 Uh oh! Incorrect answer, Try again
Use percentage composition
Empirical formula calculations
Calculate moles of each element: C(3.33), H(13.33), N(3.33)
Find simplest whole number ratio
Determine empirical formula: CH₄N
Wrong atomic mass usage
The hybridisation of C in diamond, graphite and ethyne is in the order
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Hybridization rules
Analyze carbon bonding in diamond (sp³)
Check graphite structure (sp²)
Determine ethyne hybridization (sp)
Wrong hybridization sequence
😢 Uh oh! Incorrect answer, Try again
Consider geometric arrangement
Hybridization rules
Analyze carbon bonding in diamond (sp³)
Check graphite structure (sp²)
Determine ethyne hybridization (sp)
Wrong hybridization sequence
The main axis of the diatomic molecule is Z. The orbitals Pₓ and Pᵧ overlap to form
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Molecular orbital theory
Draw orbital orientations
Analyze overlap geometry
Note perpendicular orientation to Z-axis
Wrong overlap consideration
😢 Uh oh! Incorrect answer, Try again
Consider orbital symmetry
Molecular orbital theory
Draw orbital orientations
Analyze overlap geometry
Note perpendicular orientation to Z-axis
Wrong overlap consideration
The work done when 2 moles of an ideal gas expands reversibly and isothermally from 1L to 10L at 300K is (R = 0.0083 kJ K⁻¹mol⁻¹)
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W = -2.303nRT log(V₂/V₁)
Use W = -2.303nRT log(V₂/V₁)
Insert values and calculate
W = -2.303(2)(0.0083)(300)log(10/1)
Sign convention confusion
😢 Uh oh! Incorrect answer, Try again
Isothermal expansion work
W = -2.303nRT log(V₂/V₁)
Use W = -2.303nRT log(V₂/V₁)
Insert values and calculate
W = -2.303(2)(0.0083)(300)log(10/1)
Sign convention confusion
The increasing order of bond order O₂, O₂⁺, O₂⁻ and O₂²⁻ is
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Bond order formula
Calculate bond order: (Nb-Na)/2
Count bonding and antibonding electrons
Arrange in increasing order
Wrong electron counting
😢 Uh oh! Incorrect answer, Try again
Consider electron addition/removal
Bond order formula
Calculate bond order: (Nb-Na)/2
Count bonding and antibonding electrons
Arrange in increasing order
Wrong electron counting
Consider the following sets of quantum numbers: Which setting is not permissible?
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Quantum number rules
Check quantum number rules: 0≤l≤(n-1)
Verify -l≤m≤+l
Note s can only be ±1/2
Not checking all relationships
😢 Uh oh! Incorrect answer, Try again
Consider allowed ranges
Quantum number rules
Check quantum number rules: 0≤l≤(n-1)
Verify -l≤m≤+l
Note s can only be ±1/2
Not checking all relationships
Dry ice is
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CO₂(s) → CO₂(g)
Identify phase change
Consider sublimation
Check physical properties
Students confuse different molecular solids
😢 Uh oh! Incorrect answer, Try again
Think about direct solid to gas transition
CO₂(s) → CO₂(g)
Identify phase change
Consider sublimation
Check physical properties
Students confuse different molecular solids
The energy of an electron in the nth Bohr orbit of H-atom is
🥳 Wohoo! Correct answer
En = -13.6/n² eV
Apply Bohr's theory: En = -13.6/n² eV
Calculate energy for given n
Consider negative sign for bound electron
Wrong power of n
😢 Uh oh! Incorrect answer, Try again
Remember Bohr's energy equation
En = -13.6/n² eV
Apply Bohr's theory: En = -13.6/n² eV
Calculate energy for given n
Consider negative sign for bound electron
Wrong power of n
A liquid can exist only
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Phase diagram equations
Understand phase diagram
Identify liquid region boundaries
Note liquid exists between melting and boiling at given pressure
Confusing with gas phase
😢 Uh oh! Incorrect answer, Try again
Consider pressure-temperature relationship
Phase diagram equations
Understand phase diagram
Identify liquid region boundaries
Note liquid exists between melting and boiling at given pressure
Confusing with gas phase
The shape of XeF₆ is
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VSEPR theory rules
Draw electron dot structure of XeF₆
Apply VSEPR theory with one lone pair
Determine distorted octahedral shape due to lone pair repulsion
Not considering lone pair effect
😢 Uh oh! Incorrect answer, Try again
Consider effect of lone pair
VSEPR theory rules
Draw electron dot structure of XeF₆
Apply VSEPR theory with one lone pair
Determine distorted octahedral shape due to lone pair repulsion
Not considering lone pair effect
Equilibrium constants K₁ and K₂ for the following equilibrium NO(g) + ½O₂(g) ⇌ NO₂(g) and 2NO₂(g) ⇌ 2NO(g) + O₂(g) are related as
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K(reverse) = 1/K(forward)
Write first equation and its K₁
Write second equation (reverse and multiply first)
Relate K₁ and K₂ using K for reverse reaction
Not considering equation manipulation
😢 Uh oh! Incorrect answer, Try again
Consider relationship between reactions
K(reverse) = 1/K(forward)
Write first equation and its K₁
Write second equation (reverse and multiply first)
Relate K₁ and K₂ using K for reverse reaction
Not considering equation manipulation
The correct statement regarding entropy is
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S = k ln W
Apply Third Law of Thermodynamics
Perfect crystal has no disorder at 0 K
Therefore S = 0 at absolute zero
Confusing 0°C with 0 K
😢 Uh oh! Incorrect answer, Try again
Think about molecular motion
S = k ln W
Apply Third Law of Thermodynamics
Perfect crystal has no disorder at 0 K
Therefore S = 0 at absolute zero
Confusing 0°C with 0 K
In the reaction; Fe(OH)₃(s) ⇌ Fe³⁺(eq) + 3OH⁻(aq), if the concentration of OH⁻ ions is decreased by 1/4 times, then the equilibrium concentration of Fe³⁺ will increase by
🥳 Wohoo! Correct answer
Ksp = [Fe³⁺][OH⁻]³
Write Ksp expression: Ksp = [Fe³⁺][OH⁻]³
When [OH⁻] becomes [OH⁻]/4, solve for new [Fe³⁺]
[Fe³⁺]new = 64[Fe³⁺]original to maintain Ksp
Not cubing the OH⁻ factor
😢 Uh oh! Incorrect answer, Try again
Apply Le Chatelier's principle
Ksp = [Fe³⁺][OH⁻]³
Write Ksp expression: Ksp = [Fe³⁺][OH⁻]³
When [OH⁻] becomes [OH⁻]/4, solve for new [Fe³⁺]
[Fe³⁺]new = 64[Fe³⁺]original to maintain Ksp
Not cubing the OH⁻ factor
The number of oxygen atoms in 4.4 gm of CO₂ is
🥳 Wohoo! Correct answer
n = mass/molar mass, N = n × NA
Calculate moles of CO₂: 4.4g/44g/mol = 0.1 mol
Multiply by Avogadro's number: 0.1 × 6.022 × 10²³
Multiply by 2 (oxygen atoms per CO₂): 0.1 × 2 × 6.022 × 10²³ = 1.2 × 10²³
Forgetting to multiply by atoms per molecule
😢 Uh oh! Incorrect answer, Try again
Consider molecular formula and molar mass
n = mass/molar mass, N = n × NA
Calculate moles of CO₂: 4.4g/44g/mol = 0.1 mol
Multiply by Avogadro's number: 0.1 × 6.022 × 10²³
Multiply by 2 (oxygen atoms per CO₂): 0.1 × 2 × 6.022 × 10²³ = 1.2 × 10²³
Forgetting to multiply by atoms per molecule
When an electrolyte is dissociated in solution, the van't Hoff's factor (i) is
🥳 Wohoo! Correct answer
i = actual moles/expected moles
Define van't Hoff factor (i = actual/expected moles)
Consider dissociation increases particles
Conclude i must be > 1
Forgetting to count all ions
😢 Uh oh! Incorrect answer, Try again
Compare particles before and after dissociation
i = actual moles/expected moles
Define van't Hoff factor (i = actual/expected moles)
Consider dissociation increases particles
Conclude i must be > 1
Forgetting to count all ions
If the bond energies of H-H, Br-Br H-Br are 433, 192 and 364 kJ mol⁻¹ respectively, then ΔH° for the reaction: H₂(g) + Br₂(g) → 2HBr(g) is
🥳 Wohoo! Correct answer
ΔH° = Σ(bonds broken) - Σ(bonds formed)
Sum bond energies of reactants: 433 + 192 = 625 kJ
Calculate energy for products: 2 × 364 = 728 kJ
Find ΔH° = 625 - 728 = -103 kJ
Wrong sign convention
😢 Uh oh! Incorrect answer, Try again
Consider bonds broken vs. formed
ΔH° = Σ(bonds broken) - Σ(bonds formed)
Sum bond energies of reactants: 433 + 192 = 625 kJ
Calculate energy for products: 2 × 364 = 728 kJ
Find ΔH° = 625 - 728 = -103 kJ
Wrong sign convention
Which one of the following noble gas has an unusual property of diffusing through the materials such as rubber, glass or plastic?
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Graham's law
Compare atomic size
Check diffusion rate
Consider properties
Size effect
😢 Uh oh! Incorrect answer, Try again
Smallest atom diffuses
Graham's law
Compare atomic size
Check diffusion rate
Consider properties
Size effect
Which element forms p-p π bond with itself?
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p-p π overlap
Check atomic size
Compare p orbital overlap
Consider bond strength
Orbital overlap
😢 Uh oh! Incorrect answer, Try again
Small atom better overlap
p-p π overlap
Check atomic size
Compare p orbital overlap
Consider bond strength
Orbital overlap
In manufacture of hydrogen from water gas (CO + H₂), correct statement is
🥳 Wohoo! Correct answer
CO + H₂O → CO₂ + H₂
Write reaction equation
Check conditions
Verify catalyst role
Process confusion
😢 Uh oh! Incorrect answer, Try again
Steam reforming
CO + H₂O → CO₂ + H₂
Write reaction equation
Check conditions
Verify catalyst role
Process confusion
Which statement about reaction quotient 'Qc' is incorrect?
🥳 Wohoo! Correct answer
Qc vs K relationship
Compare Q and K
Understand direction
Identify incorrect
Q/K relationship
😢 Uh oh! Incorrect answer, Try again
Q>K means reverse
Qc vs K relationship
Compare Q and K
Understand direction
Identify incorrect
Q/K relationship
A reaction has both ΔH and ΔS -ve. Rate of reaction
🥳 Wohoo! Correct answer
ΔG = ΔH - TΔS
Use ΔG equation
Analyze signs
Effect on rate
Sign convention errors
😢 Uh oh! Incorrect answer, Try again
Consider Le Chatelier
ΔG = ΔH - TΔS
Use ΔG equation
Analyze signs
Effect on rate
Sign convention errors
Equilibrium constant for N₂(g) + O₂(g) ⇌ 2NO(g) at 2000K with catalyst is
🥳 Wohoo! Correct answer
K = [NO]²/[N₂][O₂]
Note original K value
Consider catalyst effect
K remains unchanged
Catalyst misconception
😢 Uh oh! Incorrect answer, Try again
Catalyst doesn't affect K
K = [NO]²/[N₂][O₂]
Note original K value
Consider catalyst effect
K remains unchanged
Catalyst misconception
The pressure of real gases is less than ideal gas because of
🥳 Wohoo! Correct answer
P(real) < P(ideal)
Compare real vs ideal
Consider attractions
Effect on pressure
Ideal gas assumptions
😢 Uh oh! Incorrect answer, Try again
Think about forces
P(real) < P(ideal)
Compare real vs ideal
Consider attractions
Effect on pressure
Ideal gas assumptions
Which of the following is an amphoteric oxide?
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MO + H⁺ → M²⁺ + H₂O
MO + OH⁻ → MO₂²⁻
Check reaction with acid/base
Consider oxidation states
Evaluate dual nature
Confusion between basic and amphoteric oxides
😢 Uh oh! Incorrect answer, Try again
Look for intermediate oxidation states
MO + H⁺ → M²⁺ + H₂O
MO + OH⁻ → MO₂²⁻
Check reaction with acid/base
Consider oxidation states
Evaluate dual nature
Confusion between basic and amphoteric oxides
Which structure has three bond pairs and one lone pair?
🥳 Wohoo! Correct answer
Total e⁻ pairs = 4
Count electron pairs
Apply VSEPR
Determine geometry
VSEPR application
😢 Uh oh! Incorrect answer, Try again
Consider lone pairs
Total e⁻ pairs = 4
Count electron pairs
Apply VSEPR
Determine geometry
VSEPR application
The electronegativities of C, N, Si and P are in the order of
🥳 Wohoo! Correct answer
EN increases across period
Check periodic trends
Compare periods
Order by EN values
Periodic trend confusion
😢 Uh oh! Incorrect answer, Try again
Follow periodicity
EN increases across period
Check periodic trends
Compare periods
Order by EN values
Periodic trend confusion
The correct set of quantum number for unpaired electrons of chlorine atom is
🥳 Wohoo! Correct answer
n=3,l=1,m=1,s=±½
Write electronic config
Identify unpaired e⁻
Find quantum numbers
Quantum number rules
😢 Uh oh! Incorrect answer, Try again
Check quantum rules
n=3,l=1,m=1,s=±½
Write electronic config
Identify unpaired e⁻
Find quantum numbers
Quantum number rules
Which of the following oxides shows electrical properties like metals?
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Metallic conductivity in oxides
Check electronic structure
Consider d-electrons
Evaluate conductivity
Confusion between ionic and metallic oxides
😢 Uh oh! Incorrect answer, Try again
Look for transition metal
Metallic conductivity in oxides
Check electronic structure
Consider d-electrons
Evaluate conductivity
Confusion between ionic and metallic oxides
Dead burnt plaster is
🥳 Wohoo! Correct answer
CaSO₄·2H₂O → CaSO₄ + 2H₂O
Understand dehydration process
Heat above 393K
Remove water of crystallization
Students confuse plaster of Paris with dead burnt plaster
😢 Uh oh! Incorrect answer, Try again
Consider complete dehydration
CaSO₄·2H₂O → CaSO₄ + 2H₂O
Understand dehydration process
Heat above 393K
Remove water of crystallization
Students confuse plaster of Paris with dead burnt plaster
For an ideal gas, the compressibility factor is
🥳 Wohoo! Correct answer
Z = PV/nRT
Define compressibility factor
Write PV = nRT
Calculate Z = PV/nRT
Confusing Z values for ideal vs real gases.
😢 Uh oh! Incorrect answer, Try again
Z=1 for ideal gas
Z = PV/nRT
Define compressibility factor
Write PV = nRT
Calculate Z = PV/nRT
Confusing Z values for ideal vs real gases.
Acidity of BF₃ can be explained on which of the following concepts?
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Lewis acid accepts electron pair
Check electron deficiency
Consider proton transfer
Evaluate electron pair acceptance
Confusing BF₃'s behavior with Bronsted-Lowry acids.
😢 Uh oh! Incorrect answer, Try again
Look for empty orbital
Lewis acid accepts electron pair
Check electron deficiency
Consider proton transfer
Evaluate electron pair acceptance
Confusing BF₃'s behavior with Bronsted-Lowry acids.
The relationship between Kₚ and Kc is Kₚ = Kc(RT)ᐩΔn. What would be the value of Δn for the reaction, NH₄Cl(s) ⇌ NH₃(g) + HCl(g)?
🥳 Wohoo! Correct answer
Δn = moles of gaseous products - reactants
Count gaseous moles in products
Count gaseous moles in reactants
Calculate Δn = n(products) - n(reactants)
Overlooking reactant state (solid/gas) in Δn calculation.
😢 Uh oh! Incorrect answer, Try again
Consider only gaseous species
Δn = moles of gaseous products - reactants
Count gaseous moles in products
Count gaseous moles in reactants
Calculate Δn = n(products) - n(reactants)
Overlooking reactant state (solid/gas) in Δn calculation.
The state of hybrid orbitals of carbon in CO₂, CH₄ and CO₃²⁻ respectively is
🥳 Wohoo! Correct answer
Hybridization = σ bonds + lone pairs
Count electron domains
Apply VSEPR theory
Determine hybridization
Miscalculating steric number or hybridization.
😢 Uh oh! Incorrect answer, Try again
Consider geometry
Hybridization = σ bonds + lone pairs
Count electron domains
Apply VSEPR theory
Determine hybridization
Miscalculating steric number or hybridization.
Which of the following is the correct order of radius?
🥳 Wohoo! Correct answer
Ionic radius varies with charge
Compare nuclear charge
Consider electron-electron repulsion
Evaluate effective nuclear charge
Confusing atomic radius with electronegativity trends.
😢 Uh oh! Incorrect answer, Try again
More electrons = larger radius
Ionic radius varies with charge
Compare nuclear charge
Consider electron-electron repulsion
Evaluate effective nuclear charge
Confusing atomic radius with electronegativity trends.
The orbital nearest to the nucleus is
🥳 Wohoo! Correct answer
s>p>d>f penetration order
Compare penetration power
Apply (n+l) rule
Consider effective nuclear charge
Misunderstanding penetration power order of orbitals.
😢 Uh oh! Incorrect answer, Try again
Use penetration power sequence
s>p>d>f penetration order
Compare penetration power
Apply (n+l) rule
Consider effective nuclear charge
Misunderstanding penetration power order of orbitals.
In the reaction B(OH)₃ + 2H₂O → [B(OH)₄]⁻ + H₃O⁺, B(OH)₃ acts as
🥳 Wohoo! Correct answer
Lewis acid accepts electron pair
Identify electron acceptor/donor
Check proton transfer
Verify Lewis acid properties
Confusing Bronsted-Lowry with Lewis concept
😢 Uh oh! Incorrect answer, Try again
Look for electron pair acceptance
Lewis acid accepts electron pair
Identify electron acceptor/donor
Check proton transfer
Verify Lewis acid properties
Confusing Bronsted-Lowry with Lewis concept
1.0 g of Mg is burnt with 0.28 g of O₂ in a closed vessel. Which reactant is left in excess and how much?
🥳 Wohoo! Correct answer
2Mg + O₂ → 2MgO
Calculate moles of Mg = 1.0g/24g/mol = 0.0416 moles
Calculate moles of O₂ = 0.28g/32g/mol = 0.00875 moles
Compare with balanced equation 2Mg + O₂ → 2MgO
Confusing excess with limiting reagent calculations.
😢 Uh oh! Incorrect answer, Try again
Consider molar ratio 2:1
2Mg + O₂ → 2MgO
Calculate moles of Mg = 1.0g/24g/mol = 0.0416 moles
Calculate moles of O₂ = 0.28g/32g/mol = 0.00875 moles
Compare with balanced equation 2Mg + O₂ → 2MgO
Confusing excess with limiting reagent calculations.
The reaction which ΔH > ΔU is
🥳 Wohoo! Correct answer
ΔH = ΔU + ΔngRT
Check Δng
Use ΔH = ΔU + ΔngRT
Find positive Δng cases
Not considering change in moles of gas
😢 Uh oh! Incorrect answer, Try again
Look for reactions producing more gas moles
ΔH = ΔU + ΔngRT
Check Δng
Use ΔH = ΔU + ΔngRT
Find positive Δng cases
Not considering change in moles of gas
Which of the following possess net dipole moment?
🥳 Wohoo! Correct answer
μ = q × r
Check molecular geometry (bent for SO₂)
Check symmetry of charge distribution
Verify presence of polar bonds with unequal dipoles
Students often confuse molecular geometry with electron geometry
😢 Uh oh! Incorrect answer, Try again
Bent molecules with unequal charge distribution have net dipole moment
μ = q × r
Check molecular geometry (bent for SO₂)
Check symmetry of charge distribution
Verify presence of polar bonds with unequal dipoles
Students often confuse molecular geometry with electron geometry
Which of the following pair contains 2 lone pair of electrons on the central atom?
🥳 Wohoo! Correct answer
Central atom lone pairs: I₃⁻ (2), H₂O (2)
Identify molecules/ions where central atom has 2 lone pairs
Count total electrons and bonding pairs for each species
I₃⁻ has 2 lone pairs on central I, H₂O has 2 lone pairs on O
Students often forget to consider formal charges when counting lone pairs
😢 Uh oh! Incorrect answer, Try again
Draw Lewis structures to count lone pairs
Central atom lone pairs: I₃⁻ (2), H₂O (2)
Identify molecules/ions where central atom has 2 lone pairs
Count total electrons and bonding pairs for each species
I₃⁻ has 2 lone pairs on central I, H₂O has 2 lone pairs on O
Students often forget to consider formal charges when counting lone pairs
The elements in which electrons are progressively filled in 4f orbital are called
🥳 Wohoo! Correct answer
[Xe]4f¹⁻¹⁴ configuration
Identify 4f orbital filling pattern
Lanthanoids have 4f orbital filling
Progressive filling of 4f occurs
Students sometimes confuse lanthanoids with actinoids
😢 Uh oh! Incorrect answer, Try again
Remember f-block element characteristics
[Xe]4f¹⁻¹⁴ configuration
Identify 4f orbital filling pattern
Lanthanoids have 4f orbital filling
Progressive filling of 4f occurs
Students sometimes confuse lanthanoids with actinoids
Which of the following equations does NOT represent Charles's law for a given mass of gas at constant pressure?
🥳 Wohoo! Correct answer
V = KT or V/T = K
Check mathematical forms of Charles's law
Verify if each equation gives V ∝ T
log K = log V + log T doesn't show direct proportionality
Students often don't verify if equations maintain proportionality
😢 Uh oh! Incorrect answer, Try again
Remember Charles's law shows direct proportionality between V and T
V = KT or V/T = K
Check mathematical forms of Charles's law
Verify if each equation gives V ∝ T
log K = log V + log T doesn't show direct proportionality
Students often don't verify if equations maintain proportionality
Match the following acids with their pKa values: a. Phenol i. 16, b. p-Nitrophenol ii. 0.78, c. Ethanol iii. 10, d. Picric acid iv. 7.1
🥳 Wohoo! Correct answer
pKa = -log Ka
Order acids by increasing acidity
Compare substituent effects
Match pKa values accordingly
Students often forget that lower pKa means stronger acid
😢 Uh oh! Incorrect answer, Try again
Higher pKa means weaker acid
pKa = -log Ka
Order acids by increasing acidity
Compare substituent effects
Match pKa values accordingly
Students often forget that lower pKa means stronger acid
Solubility of AgCl is least in
🥳 Wohoo! Correct answer
Ksp = [Ag⁺][Cl⁻]
Consider common ion effect from Cl⁻ ions
AlCl₃ provides most Cl⁻ ions (0.3M)
Higher Cl⁻ concentration reduces AgCl solubility
Students often forget to consider the number of Cl⁻ ions per formula unit
😢 Uh oh! Incorrect answer, Try again
Remember higher chloride ion concentration decreases solubility
Ksp = [Ag⁺][Cl⁻]
Consider common ion effect from Cl⁻ ions
AlCl₃ provides most Cl⁻ ions (0.3M)
Higher Cl⁻ concentration reduces AgCl solubility
Students often forget to consider the number of Cl⁻ ions per formula unit
The first ionization enthalpy of the following elements are in the order
🥳 Wohoo! Correct answer
No specific formula required
Consider electron configuration and atomic size
Compare nuclear charge and shielding effects
Order depends on effective nuclear charge and atomic size
Students often only consider atomic size or nuclear charge, not both
😢 Uh oh! Incorrect answer, Try again
Consider both atomic size and electronic configuration
No specific formula required
Consider electron configuration and atomic size
Compare nuclear charge and shielding effects
Order depends on effective nuclear charge and atomic size
Students often only consider atomic size or nuclear charge, not both
Two particle A and B are in motion. If the wavelength associated with 'A' is 33.33 nm, the wavelength associated with 'B' whose momentum is 1/3rd of 'A' is
🥳 Wohoo! Correct answer
λ = h/p
Use de Broglie relation λ = h/p
If pₐ = 3pᵦ, then λᵦ = 3λₐ
λᵦ = 3 × 33.33 nm = 100 nm = 1.0 × 10⁻⁷m
Students sometimes inverse the relationship between momentum and wavelength
😢 Uh oh! Incorrect answer, Try again
Remember inverse relationship between momentum and wavelength
λ = h/p
Use de Broglie relation λ = h/p
If pₐ = 3pᵦ, then λᵦ = 3λₐ
λᵦ = 3 × 33.33 nm = 100 nm = 1.0 × 10⁻⁷m
Students sometimes inverse the relationship between momentum and wavelength
The mass of AgCl precipitated when a solution containing 11.70g of NaCl is added to a solution containing 3.4 g of AgNO₃ is [Atomic mass of Ag=108, Atomic mass of Na=23]
🥳 Wohoo! Correct answer
AgNO₃ + NaCl → AgCl↓ + NaNO₃
Calculate moles of NaCl and AgNO₃: NaCl = 11.70/58.5 = 0.2 mol, AgNO₃ = 3.4/170 = 0.02 mol
AgNO₃ is limiting reagent, will produce 0.02 mol AgCl
Mass of AgCl = 0.02 × 143.5 = 2.87g
Students often forget to identify limiting reagent before calculations
😢 Uh oh! Incorrect answer, Try again
Identify limiting reagent first, then calculate product
AgNO₃ + NaCl → AgCl↓ + NaNO₃
Calculate moles of NaCl and AgNO₃: NaCl = 11.70/58.5 = 0.2 mol, AgNO₃ = 3.4/170 = 0.02 mol
AgNO₃ is limiting reagent, will produce 0.02 mol AgCl
Mass of AgCl = 0.02 × 143.5 = 2.87g
Students often forget to identify limiting reagent before calculations
When the same quantity of heat is absorbed by a system at two different temperatures T₁ and T₂, such that T₁>T₂, change in entropies are ΔS₁ and ΔS₂ respectively. Then
🥳 Wohoo! Correct answer
ΔS = q/T
Apply ΔS = q/T
Compare temperatures
Compare entropy changes
Temperature effect on entropy
😢 Uh oh! Incorrect answer, Try again
Lower T gives higher ΔS
ΔS = q/T
Apply ΔS = q/T
Compare temperatures
Compare entropy changes
Temperature effect on entropy
The formal charge on central oxygen atom in ozone is
🥳 Wohoo! Correct answer
None
Count electrons
Apply formula
Calculate charge
Formal charge calculation
😢 Uh oh! Incorrect answer, Try again
FC = V - N - B/2
None
Count electrons
Apply formula
Calculate charge
Formal charge calculation
The percentage of s-character in the hybrid orbitals of nitrogen in NO₂⁻, NO₃⁻ and NH₄⁺ respectively are
🥳 Wohoo! Correct answer
None
Check hybridization
Calculate s%
Compare structures
Hybridization concepts
😢 Uh oh! Incorrect answer, Try again
s% = (# of s orbitals/# of hybrid orbitals)×100
None
Check hybridization
Calculate s%
Compare structures
Hybridization concepts
A gas mixture contains 25% He and 75% CH₄ by volume at a given temperature and pressure. The percentage by mass of methane in the mixture is approximately
🥳 Wohoo! Correct answer
nRT = PV
Calculate molar mass
Use volume ratio
Find mass percentage
Volume vs mass percentage
😢 Uh oh! Incorrect answer, Try again
Molar mass ratio affects %
nRT = PV
Calculate molar mass
Use volume ratio
Find mass percentage
Volume vs mass percentage
The conjugate base of NH₃ is
🥳 Wohoo! Correct answer
NH₃ → NH₂⁻ + H⁺
Remove H⁺
Check charge
Verify conjugate
Conjugate pairs
😢 Uh oh! Incorrect answer, Try again
Loss of proton forms base
NH₃ → NH₂⁻ + H⁺
Remove H⁺
Check charge
Verify conjugate
Conjugate pairs
The last element of the p-block in 6th period is represented by the outer most electronic configuration
🥳 Wohoo! Correct answer
None
Check period number
Identify block
Write configuration
Electronic configuration
😢 Uh oh! Incorrect answer, Try again
Complete p-block shell
None
Check period number
Identify block
Write configuration
Electronic configuration
0.4 g of dihydrogen is made to react with 7.4 g of dichlorine to form hydrogen chloride. The volume of hydrogen formed at 273K and 1 bar pressure is
🥳 Wohoo! Correct answer
H₂ + Cl₂ → 2HCl
Write equation
Calculate moles
Apply gas laws
Gas law calculations
😢 Uh oh! Incorrect answer, Try again
Use stoichiometry and PV=nRT
H₂ + Cl₂ → 2HCl
Write equation
Calculate moles
Apply gas laws
Gas law calculations
With regard to photoelectric effect, identify the correct statement
🥳 Wohoo! Correct answer
None
Check intensity effect
Compare frequency effect
Analyze work function
Photoelectric effect
😢 Uh oh! Incorrect answer, Try again
Intensity affects number of electrons
None
Check intensity effect
Compare frequency effect
Analyze work function
Photoelectric effect
Which of the following has the lowest boiling point?
🥳 Wohoo! Correct answer
None
Compare H-bonding
Check molecular mass
Analyze intermolecular forces
Intermolecular forces
😢 Uh oh! Incorrect answer, Try again
Weaker intermolecular forces
None
Compare H-bonding
Check molecular mass
Analyze intermolecular forces
Intermolecular forces
Gas liberated when II group salt containing chloride is treated with conc. H₂SO₄
🥳 Wohoo! Correct answer
MCl₂ + H₂SO₄ → MSO₄ + 2HCl
Write reaction
Identify product
Consider conditions
Confusing gas products
😢 Uh oh! Incorrect answer, Try again
Know acid reactions
MCl₂ + H₂SO₄ → MSO₄ + 2HCl
Write reaction
Identify product
Consider conditions
Confusing gas products
Which of the following is the strongest base?
🥳 Wohoo! Correct answer
None
Compare conjugate acids
Check pKa values
Rank base strength
Base strength comparison
😢 Uh oh! Incorrect answer, Try again
Stronger base has weaker conjugate acid
None
Compare conjugate acids
Check pKa values
Rank base strength
Base strength comparison
Incorrectly matched pair is:
🥳 Wohoo! Correct answer
None
Check hybridization
Verify geometry
Compare pairs
Confusion in Xe geometries
😢 Uh oh! Incorrect answer, Try again
XeF₄ is square planar
None
Check hybridization
Verify geometry
Compare pairs
Confusion in Xe geometries
Bond angle in PH₄⁺ is more than that of PH₃. This is because
🥳 Wohoo! Correct answer
None
VSEPR theory application
Lone pair effect
Bond angle comparison
Confusion about VSEPR theory
😢 Uh oh! Incorrect answer, Try again
Focus on electron pair repulsions
None
VSEPR theory application
Lone pair effect
Bond angle comparison
Confusion about VSEPR theory
Number of six-membered and five-membered rings in Buckminster Fullerene
🥳 Wohoo! Correct answer
C₆₀ structure
Count ring structures
Apply Euler's formula
Verify carbon atoms
Miscounting rings
😢 Uh oh! Incorrect answer, Try again
Know C₆₀ structure
C₆₀ structure
Count ring structures
Apply Euler's formula
Verify carbon atoms
Miscounting rings
Property of alkaline earth metals increasing with atomic number
🥳 Wohoo! Correct answer
M²⁺ + 2OH⁻ → M(OH)₂
Compare periodic trends
Check solubility pattern
Understand ionic nature
Missing periodic trends
😢 Uh oh! Incorrect answer, Try again
Know periodic trends
M²⁺ + 2OH⁻ → M(OH)₂
Compare periodic trends
Check solubility pattern
Understand ionic nature
Missing periodic trends
Ka values for H₂SO₃, HNO₂, CH₃COOH and HCN are 1.3×10⁻², 4×10⁻⁴, 1.8×10⁻⁵ and 4×10⁻¹⁰ respectively. Which produces stronger conjugate base?
🥳 Wohoo! Correct answer
Ka₁ > Ka₂ means Kb₁ < Kb₂
Compare Ka values
Lower Ka means stronger conjugate base
HCN has lowest Ka
Forgetting Ka-Kb relationship
😢 Uh oh! Incorrect answer, Try again
Look for lowest Ka
Ka₁ > Ka₂ means Kb₁ < Kb₂
Compare Ka values
Lower Ka means stronger conjugate base
HCN has lowest Ka
Forgetting Ka-Kb relationship
For reaction A(g) + B(g) ⇌ C(g) + D(g); ΔH = -Q KJ, equilibrium constant cannot be disturbed by
🥳 Wohoo! Correct answer
Δn = n(products) - n(reactants)
Count gas moles on both sides
Calculate Δn = 2-2 = 0
Apply Le Chatelier's principle
Forgetting to count gas moles
😢 Uh oh! Incorrect answer, Try again
Count total gas moles
Δn = n(products) - n(reactants)
Count gas moles on both sides
Calculate Δn = 2-2 = 0
Apply Le Chatelier's principle
Forgetting to count gas moles
Which among the following has highest pH?
🥳 Wohoo! Correct answer
pH = -log[H⁺]
Compare acid/base strengths
Consider concentrations
Higher [OH⁻] = higher pH
Confusing pH scale
😢 Uh oh! Incorrect answer, Try again
Strong base has highest pH
pH = -log[H⁺]
Compare acid/base strengths
Consider concentrations
Higher [OH⁻] = higher pH
Confusing pH scale
1 mole of HI is heated in a closed container of 2L. At equilibrium half a mole of HI is dissociated. The equilibrium constant of the reaction is
🥳 Wohoo! Correct answer
Kc = [H₂][I₂]/[HI]²
Write equilibrium reaction
Calculate equilibrium concentrations
Use Kc formula
Forgetting concentration units
😢 Uh oh! Incorrect answer, Try again
Consider stoichiometry of dissociation
Kc = [H₂][I₂]/[HI]²
Write equilibrium reaction
Calculate equilibrium concentrations
Use Kc formula
Forgetting concentration units
In oxygen and carbon molecule the bonding is
🥳 Wohoo! Correct answer
Bond Order = (Nb - Na)/2
Write molecular orbital configurations
Count bond order
Compare bond types
Confusing MO configurations
😢 Uh oh! Incorrect answer, Try again
MO diagram shows bond types
Bond Order = (Nb - Na)/2
Write molecular orbital configurations
Count bond order
Compare bond types
Confusing MO configurations
Elements X, Y and Z have atomic numbers 19, 37 and 55 respectively. Which of the following statements is true about them?
🥳 Wohoo! Correct answer
Group 1: IE(K) > IE(Rb) > IE(Cs)
Identify elements (K, Rb, Cs)
Consider periodic trends
Compare ionization energies
Confusing periodic trends
😢 Uh oh! Incorrect answer, Try again
IE decreases down the group
Group 1: IE(K) > IE(Rb) > IE(Cs)
Identify elements (K, Rb, Cs)
Consider periodic trends
Compare ionization energies
Confusing periodic trends
The volume of 2.8g of CO at 27°C and 0.821 atm pressure is (R = 0.08210 lit.atm.K⁻¹mol⁻¹)
🥳 Wohoo! Correct answer
PV = nRT; V = nRT/P
Use ideal gas equation PV=nRT
Calculate moles of CO (2.8/28)
Solve for V
Forgetting temperature conversion
😢 Uh oh! Incorrect answer, Try again
Remember to use Kelvin temperature
PV = nRT; V = nRT/P
Use ideal gas equation PV=nRT
Calculate moles of CO (2.8/28)
Solve for V
Forgetting temperature conversion
If wavelength of photon is 2.2×10⁻¹¹ m and h = 6.6×10⁻³⁴ Js, then momentum of photon is
🥳 Wohoo! Correct answer
p = h/λ
Use p = h/λ
Insert values
Calculate momentum
Unit conversion errors
😢 Uh oh! Incorrect answer, Try again
Photon momentum inversely proportional to wavelength
p = h/λ
Use p = h/λ
Insert values
Calculate momentum
Unit conversion errors
Correct order of first ionization enthalpy
🥳 Wohoo! Correct answer
IE trends
Compare atomic size
Check electronic configuration
Consider effective nuclear charge
Trend confusion
😢 Uh oh! Incorrect answer, Try again
Periodic trends
IE trends
Compare atomic size
Check electronic configuration
Consider effective nuclear charge
Trend confusion
Which is most VISCOUS?
🥳 Wohoo! Correct answer
Glycerol has 3 -OH groups
Compare hydrogen bonding
Consider molecular size
More -OH groups = higher viscosity
Confusing factors affecting viscosity
😢 Uh oh! Incorrect answer, Try again
Hydrogen bonding affects viscosity
Glycerol has 3 -OH groups
Compare hydrogen bonding
Consider molecular size
More -OH groups = higher viscosity
Confusing factors affecting viscosity
A pair of amphoteric oxides is
🥳 Wohoo! Correct answer
BeO + 2H⁺/2OH⁻ reactions
Check oxide nature
Compare reactions
Verify amphoterism
Amphoteric behavior confusion
😢 Uh oh! Incorrect answer, Try again
React with acid & base
BeO + 2H⁺/2OH⁻ reactions
Check oxide nature
Compare reactions
Verify amphoterism
Amphoteric behavior confusion
Number of protons, neutrons and electrons in ₁₆S²⁻ ion
🥳 Wohoo! Correct answer
Mass number = p + n
Find atomic number
Calculate neutrons
Count electrons
Ion electron confusion
😢 Uh oh! Incorrect answer, Try again
Consider charge
Mass number = p + n
Find atomic number
Calculate neutrons
Count electrons
Ion electron confusion
pH of mixture of weak acid (pKa=5.9) and weak base (pKb=5.8) in equal proportions
🥳 Wohoo! Correct answer
pH = 7 + ½(5.9 - 5.8)
Use Henderson equation
Calculate pH
Consider equal proportions
pH calculation confusion
😢 Uh oh! Incorrect answer, Try again
pH = 7 + ½(pKa - pKb)
pH = 7 + ½(5.9 - 5.8)
Use Henderson equation
Calculate pH
Consider equal proportions
pH calculation confusion
Temperature of 25°C in Fahrenheit and Kelvin scales
🥳 Wohoo! Correct answer
Temperature conversions
Convert to Fahrenheit
Convert to Kelvin
Check both conversions
Temperature scale confusion
😢 Uh oh! Incorrect answer, Try again
°F = (9/5)°C + 32, K = °C + 273.15
Temperature conversions
Convert to Fahrenheit
Convert to Kelvin
Check both conversions
Temperature scale confusion
At 500K, KC=2×10⁻⁵ for A₂(g) + B₂(g) ⇌ 2AB(g). With catalyst making equilibrium 10× faster, new KC is
🥳 Wohoo! Correct answer
KC remains same
Consider catalyst effect
Check equilibrium constant
Analyze temperature dependence
Catalyst effect confusion
😢 Uh oh! Incorrect answer, Try again
Catalyst doesn't affect KC
KC remains same
Consider catalyst effect
Check equilibrium constant
Analyze temperature dependence
Catalyst effect confusion
Enthalpy of solution for NaCl with lattice enthalpy 788 kJ mol⁻¹ and ΔH(hyd) -784 kJ mol⁻¹
🥳 Wohoo! Correct answer
788 + (-784) = 4
Use Born-Haber cycle
Add enthalpies
Consider signs
Sign convention confusion
😢 Uh oh! Incorrect answer, Try again
ΔH(sol) = ΔH(L) + ΔH(hyd)
788 + (-784) = 4
Use Born-Haber cycle
Add enthalpies
Consider signs
Sign convention confusion
Which pair of elements doesn't have (n-1)d¹⁰ns² configuration?
🥳 Wohoo! Correct answer
Cu:[Ar]3d¹⁰4s¹
Write configurations
Check d-block filling
Compare pairs
Configuration patterns
😢 Uh oh! Incorrect answer, Try again
Electronic stability
Cu:[Ar]3d¹⁰4s¹
Write configurations
Check d-block filling
Compare pairs
Configuration patterns
Final pressure when 2 atm gas heated from 25°C to 323°C and compressed to 2/3 original volume
🥳 Wohoo! Correct answer
P₂ = (2×3×596)/(298×2)
Use combined gas law
Convert temperature
Calculate P₂
Temperature conversion confusion
😢 Uh oh! Incorrect answer, Try again
P₁V₁/T₁ = P₂V₂/T₂
P₂ = (2×3×596)/(298×2)
Use combined gas law
Convert temperature
Calculate P₂
Temperature conversion confusion
Purpose of adding NH₄Cl to NH₄OH in the analysis of Group III basic radicals...
🥳 Wohoo! Correct answer
NH₄Cl addition suppresses NH₄OH dissociation.
NH₄Cl suppresses NH₄OH dissociation due to the common ion effect.
Recognize the role of NH₄Cl in suppressing OH⁻ ion increase, facilitating selective precipitation.
NH₄Cl suppresses NH₄OH dissociation due to the common ion effect.
Confusing role of NH₄Cl in Group III analysis.
😢 Uh oh! Incorrect answer, Try again
Focus on the effect of common ions in suppressing dissociation.
NH₄Cl addition suppresses NH₄OH dissociation.
NH₄Cl suppresses NH₄OH dissociation due to the common ion effect.
Recognize the role of NH₄Cl in suppressing OH⁻ ion increase, facilitating selective precipitation.
NH₄Cl suppresses NH₄OH dissociation due to the common ion effect.
Confusing role of NH₄Cl in Group III analysis.
When FeCl₃ added to excess hot water gives sol X and to NaOH(aq) gives Y. X and Y are
🥳 Wohoo! Correct answer
FeCl₃ + H₂O → Fe₂O₃·xH₂O + HCl
Identify hydrolysis products
Check stabilizing ions
Compare both conditions
Confusion in stabilizing ions
😢 Uh oh! Incorrect answer, Try again
Look for charge balancing
FeCl₃ + H₂O → Fe₂O₃·xH₂O + HCl
Identify hydrolysis products
Check stabilizing ions
Compare both conditions
Confusion in stabilizing ions
For formation of which compound in Ellingham diagram ΔG° becomes more and more negative with increase in temperature?
🥳 Wohoo! Correct answer
C(s) + ½O₂(g) → CO(g)
Check entropy change
Compare moles of gases
CO shows negative slope
All oxide formations follow same trend
😢 Uh oh! Incorrect answer, Try again
Look for more gaseous products
C(s) + ½O₂(g) → CO(g)
Check entropy change
Compare moles of gases
CO shows negative slope
All oxide formations follow same trend
The energy associated with the first orbit of He+ is:
🥳 Wohoo! Correct answer
En = -2.18 × 10^-18 Z^2/n^2.
Use the formula En = -2.18 × 10^-18 Z^2/n^2, where Z = 2 for He+ and n = 1.
Substituting values: En = -2.18 × 10^-18 × 4 = -8.72 × 10^-18.
Final Answer: Energy = -8.72 × 10^-18 J; Option B is correct.
Misplacing Z or n values in the formula for hydrogen-like species.
😢 Uh oh! Incorrect answer, Try again
Apply the energy equation for hydrogen-like species.
En = -2.18 × 10^-18 Z^2/n^2.
Use the formula En = -2.18 × 10^-18 Z^2/n^2, where Z = 2 for He+ and n = 1.
Substituting values: En = -2.18 × 10^-18 × 4 = -8.72 × 10^-18.
Final Answer: Energy = -8.72 × 10^-18 J; Option B is correct.
Misplacing Z or n values in the formula for hydrogen-like species.
The synthetically produced radioactive noble gas by collision of 249Cf with 48Ca is:
🥳 Wohoo! Correct answer
Reaction formula: 249Cf + 48Ca.
Use the fusion reaction: 249Cf + 48Ca → 294Og + 3n.
Recognize that Oganesson (Og, Z=118) is the product of this synthetic reaction.
Final Answer: Oganesson (Og) is synthetically produced in this reaction.
Confusing other noble gases with the synthesized element (Og).
😢 Uh oh! Incorrect answer, Try again
Relate atomic structure and fusion reactions.
Reaction formula: 249Cf + 48Ca.
Use the fusion reaction: 249Cf + 48Ca → 294Og + 3n.
Recognize that Oganesson (Og, Z=118) is the product of this synthetic reaction.
Final Answer: Oganesson (Og) is synthetically produced in this reaction.
Confusing other noble gases with the synthesized element (Og).
Halide that cannot be hydrolyzed is...
🥳 Wohoo! Correct answer
Hydrolysis needs d-orbitals, absent in carbon.
CCl₄ cannot be hydrolyzed due to the absence of d-orbitals in carbon.
Recognize that hydrolysis requires availability of d-orbitals.
Final result: CCl₄ cannot hydrolyze.
Assuming all halides undergo hydrolysis.
😢 Uh oh! Incorrect answer, Try again
Understand the role of d-orbitals in hydrolysis reactions.
Hydrolysis needs d-orbitals, absent in carbon.
CCl₄ cannot be hydrolyzed due to the absence of d-orbitals in carbon.
Recognize that hydrolysis requires availability of d-orbitals.
Final result: CCl₄ cannot hydrolyze.
Assuming all halides undergo hydrolysis.
Solubility product of CaC₂O₄ is 4 × 10⁻⁹. Its solubility in pure water is...
🥳 Wohoo! Correct answer
Ksp = S² → Solve for S.
Solubility (S) is calculated from Ksp = S² for salts dissociating into 1:1 cations and anions.
Ksp = S² → Solve for S: √(4 × 10⁻⁹) = 6.3 × 10⁻⁵.
Solubility = 6.3 × 10⁻⁵ mol/L.
Miscalculating solubility for salts dissociating into 1:1 ions.
😢 Uh oh! Incorrect answer, Try again
Use Ksp formula correctly for solubility.
Ksp = S² → Solve for S.
Solubility (S) is calculated from Ksp = S² for salts dissociating into 1:1 cations and anions.
Ksp = S² → Solve for S: √(4 × 10⁻⁹) = 6.3 × 10⁻⁵.
Solubility = 6.3 × 10⁻⁵ mol/L.
Miscalculating solubility for salts dissociating into 1:1 ions.
A pair of isoelectronic species with bond order of 1 is:
🥳 Wohoo! Correct answer
Bond order = 1/2 (Bonding electrons - Antibonding electrons).
Isoelectronic species O2- and F2 both have 18 electrons and bond order of 1.
Compare electronic configuration and bond order of the given species.
Final Answer: O2- and F2 have bond order 1; Option C is correct.
Overlooking isoelectronic nature or miscalculating bond order for given species.
😢 Uh oh! Incorrect answer, Try again
Use bond order formulas and molecular configurations.
Bond order = 1/2 (Bonding electrons - Antibonding electrons).
Isoelectronic species O2- and F2 both have 18 electrons and bond order of 1.
Compare electronic configuration and bond order of the given species.
Final Answer: O2- and F2 have bond order 1; Option C is correct.
Overlooking isoelectronic nature or miscalculating bond order for given species.
Identify the wrong relation for real gases:
🥳 Wohoo! Correct answer
Van der Waals equation corrections.
Compressibility factor Z = pV/nRT, not directly Vreal/Videal.
Real gas behavior is modeled using Van der Waals corrections, including p and V adjustments.
Final Answer: Option A is incorrect as Z involves pressure, volume, and temperature.
Confusing Z with a simplistic ratio of real and ideal volumes.
😢 Uh oh! Incorrect answer, Try again
Recall the real gas compressibility factor Z.
Van der Waals equation corrections.
Compressibility factor Z = pV/nRT, not directly Vreal/Videal.
Real gas behavior is modeled using Van der Waals corrections, including p and V adjustments.
Final Answer: Option A is incorrect as Z involves pressure, volume, and temperature.
Confusing Z with a simplistic ratio of real and ideal volumes.