OCR A CHEMISTRY A LEVEL
PAPER 1
1. What are the equations for the amount of substance?
A. mass = moles ÷ Mr
B. mol = vol ÷ conc
✅ C. mass = Mr × moles; mol = vol × conc; vol(gas) = mol × 24 (dm³); PV = nRT
D. moles = mass × Mr
2. What is the Empirical Formula?
A. The total number of atoms in a molecule
✅ B. The simplest whole number ratio of atoms of each element in a compound
C. The molecular formula of a compound
D. The number of ions in a salt
3. What is the Molecular Formula?
✅ A. The number and type of atoms of each element in a molecule
B. The formula showing the simplest ratio of elements
C. The structure showing bonds
D. The ionic representation of a compound
4. What does “Anhydrous” mean?
✅ A. Contains no water molecules
B. Contains one water molecule
C. Contains multiple water molecules
D. Has absorbed water vapor
5. What does “Hydrated” mean?
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,A. Dry crystalline compound
✅ B. Crystalline compound containing water molecules
C. Compound without any hydrogen
D. Gas dissolved in water
6. How do you convert Celsius to Kelvin?
A. K = C – 273
✅ B. K = C + 273
C. K = C × 273
D. K = 273 – C
7. What is the formula for % yield and atom economy?
✅ A. % yield = (actual ÷ theoretical) × 100; atom economy = (desired products ÷ all reactants)
× 100
B. % yield = (theoretical ÷ actual) × 100
C. Atom economy = (reactants ÷ products) × 100
D. % yield = (mass reactant ÷ mass product) × 100
8. What is the appearance of Cu²⁺ in aqueous solution?
✅ A. [Cu(H₂O)₆]²⁺ — Pale blue
B. [Cu(H₂O)₆]³⁺ — Yellow
C. [CuCl₄]²⁻ — Green
D. [Cu(NH₃)₄]²⁺ — Dark blue
9. What is the appearance of Fe²⁺ in aqueous solution?
✅ A. [Fe(H₂O)₆]²⁺ — Pale green
B. [Fe(H₂O)₆]³⁺ — Yellow
C. [Fe(OH)₃] — Orange
D. [Fe(OH)₂] — Green
10. What is the appearance of Fe³⁺ in aqueous solution?
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, A. Pale green
✅ B. Yellow — [Fe(H₂O)₆]³⁺
C. Pink — [Fe(H₂O)₆]²⁺
D. Grey-green
11. What is the appearance of Mn²⁺ in aqueous solution?
✅ A. [Mn(H₂O)₆]²⁺ — Pale pink
B. [Mn(H₂O)₆]³⁺ — Orange
C. [Mn(OH)₂] — Brown
D. [Mn(NH₃)₆]²⁺ — Green
12. What is the appearance of Cr³⁺ in aqueous solution?
✅ A. [Cr(H₂O)₆]³⁺ — Green
B. [Cr(OH)₆]³⁻ — Dark green
C. [Cr(NH₃)₆]³⁺ — Purple
D. [CrCl₆]³⁻ — Yellow
13. What is a Transition Element?
✅ A. A d-block element that forms at least one stable ion with a partially filled d-orbital
B. Any element with d-electrons
C. A metal that can form ions
D. Any element with variable oxidation states
14. What is a Complex Ion?
✅ A. A metal ion surrounded by coordinately bonded ligands
B. A salt formed from acid and base
C. A non-metal ion in solution
D. A hydrated compound
15. What is a Ligand?
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PAPER 1
1. What are the equations for the amount of substance?
A. mass = moles ÷ Mr
B. mol = vol ÷ conc
✅ C. mass = Mr × moles; mol = vol × conc; vol(gas) = mol × 24 (dm³); PV = nRT
D. moles = mass × Mr
2. What is the Empirical Formula?
A. The total number of atoms in a molecule
✅ B. The simplest whole number ratio of atoms of each element in a compound
C. The molecular formula of a compound
D. The number of ions in a salt
3. What is the Molecular Formula?
✅ A. The number and type of atoms of each element in a molecule
B. The formula showing the simplest ratio of elements
C. The structure showing bonds
D. The ionic representation of a compound
4. What does “Anhydrous” mean?
✅ A. Contains no water molecules
B. Contains one water molecule
C. Contains multiple water molecules
D. Has absorbed water vapor
5. What does “Hydrated” mean?
1
,A. Dry crystalline compound
✅ B. Crystalline compound containing water molecules
C. Compound without any hydrogen
D. Gas dissolved in water
6. How do you convert Celsius to Kelvin?
A. K = C – 273
✅ B. K = C + 273
C. K = C × 273
D. K = 273 – C
7. What is the formula for % yield and atom economy?
✅ A. % yield = (actual ÷ theoretical) × 100; atom economy = (desired products ÷ all reactants)
× 100
B. % yield = (theoretical ÷ actual) × 100
C. Atom economy = (reactants ÷ products) × 100
D. % yield = (mass reactant ÷ mass product) × 100
8. What is the appearance of Cu²⁺ in aqueous solution?
✅ A. [Cu(H₂O)₆]²⁺ — Pale blue
B. [Cu(H₂O)₆]³⁺ — Yellow
C. [CuCl₄]²⁻ — Green
D. [Cu(NH₃)₄]²⁺ — Dark blue
9. What is the appearance of Fe²⁺ in aqueous solution?
✅ A. [Fe(H₂O)₆]²⁺ — Pale green
B. [Fe(H₂O)₆]³⁺ — Yellow
C. [Fe(OH)₃] — Orange
D. [Fe(OH)₂] — Green
10. What is the appearance of Fe³⁺ in aqueous solution?
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, A. Pale green
✅ B. Yellow — [Fe(H₂O)₆]³⁺
C. Pink — [Fe(H₂O)₆]²⁺
D. Grey-green
11. What is the appearance of Mn²⁺ in aqueous solution?
✅ A. [Mn(H₂O)₆]²⁺ — Pale pink
B. [Mn(H₂O)₆]³⁺ — Orange
C. [Mn(OH)₂] — Brown
D. [Mn(NH₃)₆]²⁺ — Green
12. What is the appearance of Cr³⁺ in aqueous solution?
✅ A. [Cr(H₂O)₆]³⁺ — Green
B. [Cr(OH)₆]³⁻ — Dark green
C. [Cr(NH₃)₆]³⁺ — Purple
D. [CrCl₆]³⁻ — Yellow
13. What is a Transition Element?
✅ A. A d-block element that forms at least one stable ion with a partially filled d-orbital
B. Any element with d-electrons
C. A metal that can form ions
D. Any element with variable oxidation states
14. What is a Complex Ion?
✅ A. A metal ion surrounded by coordinately bonded ligands
B. A salt formed from acid and base
C. A non-metal ion in solution
D. A hydrated compound
15. What is a Ligand?
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