SECTION 1 — 20 marks
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2018 SQA Higher Chemistry MCQS With Answers

1. The potential energy diagram below refers to the reversible reaction involving reactants R
and products P.

What is the enthalpy change, in kJ mol−1, for the reverse reaction?

  • A −40
  • B −10
  • C +10
  • D +30

Ans B

2. The relative rate of a reaction which reached completion in 1 minute 40 seconds is

  • A 0·010 s−1
  • B 0·714 s−1
  • C 0·010 min−1
  • D 0·714 min−1

Ans A

3.


Which of the following is the correct interpretation of the above energy distribution
diagram for a reaction as the temperature decreases from T2 to T1?

Activation energy (EA)                       Number of successful collisions

  • A                      remains the same                                                  increases
  • B                         decreases                                                              decreases
  • C                         decreases                                                                increases
  • D                       remains the same                                                 decreases

Ans D

  4. The table shows the first three ionisation energies of aluminium.

Using this information, what is the enthalpy change, in kJ mol−1, for the following reaction?
Al+(g) ↓ Al3+(g) + 2e−

  • A 1817
  • B 2395
  • C 4562
  • D 5140

Ans C

5. An element contains covalent bonding and London dispersion forces.
The element could be

  • A boron
  • B neon
  • C sodium
  • D sulfur.

Ans D

6. Erythrose is a chemical that is known to kill cancer cells.

The two functional groups present in erythrose are

  • A carboxyl and ester
  • B carbonyl and ester
  • C carbonyl and hydroxyl
  • D carboxyl and hydroxyl.

Ans C

7.

The name of the above compound is

  • A 2,2,3-trimethylbutanoic acid
  • B 2,3,3-trimethylbutanoic acid
  • C 1,1,2,2-tetramethylpropanoic acid
  • D 2,2,3,3-tetramethylpropanoic acid.

Ans A

8. Which of the following is an isomer of pentan-3-ol?

  • A CH3CH2CH(OH)CH2CH3
  • B CH3CHCHCH2CH2OH
  • C CH3CHCHCH(OH)CH3
  • D CH3CH(CH3)CH2CH2OH

Ans D

9. Oxidation of 4-methylpentan-2-ol to the corresponding ketone results in the alcohol

  • A losing 2 g per mole
  • B gaining 2 g per mole
  • C losing 16 g per mole
  • D gaining 16 g per mole.

Ans A

10. Essential amino acids are defined as the amino acids which

  • A are necessary for building proteins
  • B humans must acquire through their diet
  • C plants cannot synthesise for themselves
  • D are produced when any protein is hydrolysed.

Ans B

11. A mixture of carbon monoxide and hydrogen can be converted into water and a mixture of
hydrocarbons.
                n CO + (2n + 1) H2 ↓ n H2O + hydrocarbons
What is the general formula for the hydrocarbons produced?

  • A CnH2n−2
  • B CnH2n
  • C CnH2n+1
  • D CnH2n+2

Ans D

12. A mixture of sodium chloride and sodium sulfate is known to contain 0∙6 mol of chloride
ions and 0∙2 mol of sulfate ions.
How many moles of sodium ions are present?

  • A 0∙4
  • B 0∙5
  • C 0∙8
  • D 1∙0

Ans D

13. Under the same conditions of temperature and pressure, which of the following gases would
occupy the largest volume?

  • A 0·20 g of hydrogen
  • B 0·44 g of carbon dioxide
  • C 0·60 g of neon
  • D 0·80 g of argon

Ans A

14. 3CuO + 2NH3 ↓ 3Cu + N2 + 3H2O
What volume of gas, in cm3, would be obtained by reaction between 100 cm3 of ammonia
gas and excess copper(II) oxide? All volumes are measured at atmospheric pressure and 20 °C.

  • A 50
  • B 100
  • C 200
  • D 400

Ans A

15. Cl2(g) + H2O(ℓ) Ý Cl−(aq) + ClO−(aq) + 2H+(aq )
The addition of which of the following substances would move the above equilibrium to the
right?

  • A Hydrogen
  • B Hydrogen chloride
  • C Sodium chloride
  • D Sodium hydroxide

Ans D

16. When 3·6 g of butanal (mass of one mole = 72 g) was burned, 124 kJ of energy was released.
What is the enthalpy of combustion of butanal, in kJ mol−1?

  • A −6·2
  • B +6·2
  • C −2480
  • D +2480

Ans C

17. Consider the reaction pathways shown below.

According to Hess’s Law, the enthalpy change, in kJ mol−1, for reaction X is

  • A +111
  • B −111
  • C −677
  • D +677.

Ans B

18. SO32−(aq) + H2O(ℓ) ↓ SO42−(aq) + 2H+(aq) + 2e−
Which of the following ions could be used to oxidise sulfite ions to sulfate ions?

  • A Cr3+(aq)
  • B Al3+(aq)
  • C Fe3+(aq)
  • D Sn4+(aq)

Ans C

19. During a redox reaction nitrate ions, NO3−, are converted to nitrogen monoxide, NO.

NO3−↓ NO
Which line in the table correctly completes the ion-electron equation?
Reactants                               Products

  • A                      6H+ + 5e−                              3H2O
  • B                      4H+ + 3e−                               2H2O
  • C                      6H+ 3H2O +                                 5e−
  • D                      4H+ 2H2O +                                 3e−

Ans B

20. ICl(ℓ) + Cl2(g) Ý ICl3(s) ΔH = −106kJ mol−1
Which line in the table identifies correctly the changes that will cause the greatest increase
in the proportion of solid in the above equilibrium mixture?

       Temperature                      Pressure

  • A           decrease                                     decrease
  • B           decrease                                     increase
  • C           increase                                     decrease
  • D          increase                                      increase

Ans B

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