Chemistry Section 1 2016 ( Solved ) Mcqs of National 5 SQA

1. Particles with the same electron arrangement are said to be isoelectronic.
Which of the following compounds contains ions which are isoelectronic?

  • A Na2S
  • B MgCl2
  • C KBr
  • D CaCl2

Ans : D CaCl2

2. Which line in the table is correct for the polar covalent bond in hydrogen chloride?

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Ans : A

3. Which of the following compounds has the greatest ionic character?

  • A Caesium fluoride
  • B Caesium iodide
  • C Sodium fluoride
  • D Sodium iodide

Ans : A Caesium fluoride

4. The diagram below shows the energy profiles for a reaction carried out with and without a

What is the enthalpy change, in kJ mol–1, for the catalysed reaction?

  • A –100
  • B –50
  • C +50
  • D +100

Ans : B –50

5. Limonene is a terpene molecule present in lemons

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How many isoprene units are joined together in a limonene molecule?

  • A 1
  • B 2
  • C 3
  • D 4

Ans : B 2

6. The following molecules give flavour to food.

Which of the following flavour molecules would be most likely to be retained in the food
when the food is cooked in water?

Ans : A

7. vegetable oil vegetable fat
Which of the following reactions brings about the above change?

  • A Hydrolysis
  • B Condensation
  • C Hydrogenation
  • D Dehydrogenation

Ans : C

8. The rate of hydrolysis of protein, using an enzyme, was studied at different temperatures.
Which of the following graphs would be obtained?

Ans : D

9. Which of the following is the salt of a long-chain fatty acid?

  • A Fat
  • B Oil
  • C Soap
  • D Glycerol

Ans: C

10. Emulsifiers for use in food are commonly made by reacting edible oils with

  • A esters
  • B glycerol
  • C fatty acids
  • D amino acids.

Ans : B

11. The equation for the reduction reaction taking place when ethanal reacts with Tollens’
reagent is

Ans : B

12. The name of the compound with structure:

  • A 2,3-dimethylpentan-4-one
  • B 2,3-dimethylpentan-2-al
  • C 3,4-dimethylpentan-2-one
  • D 3,4-dimethylpentan-2-al.

Ans : C

15. In a reversible reaction, equilibrium is reached when

  • A molecules of reactants cease to change into molecules of products
  • B the concentrations of reactants and products are equal
  • C the concentrations of reactants and products are constant
  • D the activation energy of the forward reaction is equal to that of the reverse reaction.

Ans : C

16. Which of the following equations represents the enthalpy of combustion of propane?

  • A C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(ℓ)
  • B C3H8(g) + 7/2 O2(g) → 3CO(g) + 4H2O(ℓ)
  • C C3H8(g) + 3O2(g) → 3CO2(g) + 4H2(g)
  • D C3H8(g) + 3/2 O2(g) → 3CO(g) + 4H2(g)

Ans : A

17. An oxidising agent

  • A gains electrons and is oxidised
  • B loses electrons and is oxidised
  • C gains electrons and is reduced
  • D loses electrons and is reduced.

Ans : C

18. During a redox process in acid solution, chlorate ions, ClO3

(aq), are converted into chlorine, Cl2(g).ClO3
(aq) → Cl2(g)
The numbers of H+ (aq) and H2O(ℓ) required to balance the ion-electron equation for the
formation of 1 mol of Cl2(g) are, respectively

A 3 and 6

B 6 and 3

C 6 and 12

D 12 and 6.

Ans : D

19. Which of the following ions could be used to oxidise iodide ions to iodine?
2I−(aq) → I2(s) + 2e−

Ans : D

A student was carrying out a titration to establish the concentration of vitamin C using
iodine solution.
Which of the following would help the student achieve a precise end-point?

  • A Placing a white tile underneath the conical flask
  • B Using the bottom of the meniscus when reading the burette
  • C Repeating titrations
  • D Carrying out a rough titration first

Ans : A


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