SECTION 1

2017 National 5 SQA Chemistry MCQS With Answers

1. In a reaction, the mass lost in 30 seconds was 2 g.
What is the average rate of reaction, in g s, over this time?

  • A 1/30
  • B 30/2
  • C 1/2
  • D 2/30

Ans D

2. An atom has 21 protons, 21 electrons and 24 neutrons.
The atom has

  • A atomic number 24 and mass number 42
  • B atomic number 45 and mass number 21
  • C atomic number 21 and mass number 45
  • D atomic number 24 and mass number 45.

Ans C

3. What is the charge on the zinc ion in zinc dichromate, ZnCr2O7?
You may wish to use the data booklet to help you.

  • A 2+
  • B 2−
  • C 1+
  • D 1−

Ans A

4. The table contains information about magnesium and magnesium chloride.

When molten magnesium chloride is electrolysed at 730 °C the magnesium appears as a

  • A solid on the surface of the molten magnesium chloride
  • B solid at the bottom of the molten magnesium chloride
  • C liquid at the bottom of the molten magnesium chloride
  • D liquid on the surface of the molten magnesium chloride.

Ans D

5. Which of the following compounds is a base?

  • A Sodium carbonate
  • B Sodium chloride
  • C Sodium nitrate
  • D Sodium sulfate

Ans A

6. AgNO3(aq) + KCl(aq) AgCl(s) + KNO3(aq)
Which of the following are the spectator ions in this reaction?

  • A Ag+and Cl−
  • B K+and NO3−
  • C Ag+and NO3−
  • D K+and Cl−

Ans B

7. x H2O2 y H2O + z O2
This equation will be balanced when

  • A x = 1, y = 2 and z = 2
  • B x = 1, y = 1 and z = 2
  • C x = 2, y = 2 and z = 1
  • D x = 2, y = 2 and z = 2.

Ans C

8. 0·25 moles of a gas has a mass of 7 g.
Which of the following could be the molecular formula for the gas?

  • A C2H6
  • B C2H4
  • C C3H8
  • D C3H6

Ans B

9. Which of the following solutions contains the least number of moles of solute?

  • A 100 cm3 of 0·4 mol l−1solution
  • B 200 cm3 of 0·3 mol l−1solution
  • C 300 cm3of 1·0 mol l−1solution
  • D 400 cm3of 0·5 mol l−1solution

Ans A

10. Which of the following could be the molecular formula for an alkane?

  • A C7H16
  • B C7H14
  • C C7H12
  • D C7H10

Ans A

11. A student added bromine solution to compound X and compound Y.

Which line in the table is correct?

Decolourises bromine solution immediately
                          Compound X            Compound Y

  • A                              no                                              no
  • B                              no                                                yes
  • C                             yes                                                  yes
  • D                            yes                                                     no

Ans D

12. A compound burns in air. The only products of the reaction are carbon dioxide, sulfur dioxide
and water.
The compound must contain

  • A carbon and sulfur only
  • B carbon and hydrogen only
  • C carbon, hydrogen and sulfur
  • D carbon, hydrogen, sulfur and oxygen.

Ans C

13. Vinegar is a solution of

  • A ethanol
  • B methanol
  • C ethanoic acid
  • D methanoic acid.

Ans C

14. A reaction is exothermic if

  • A energy is absorbed from the surroundings
  • B energy is released to the surroundings
  • C energy is required to start the reaction
  • D there is no energy change.

Ans B

15. Which of the following diagrams could be used to represent the structure of copper?

Ans D

16. Which of the following metals is found uncombined in the Earth’s crust?
You may wish to use the data booklet to help you.

  • A Tin
  • B Magnesium
  • C Gold
  • D Sodium

Ans C

17. Which of the following is not an essential element for healthy plant growth?

  • A Oxygen
  • B Nitrogen
  • C Potassium
  • D Phosphorus

Ans A

18. The Haber process is the industrial process for the manufacture of

  • A nitric acid
  • B ammonia
  • C alkenes
  • D esters.

Ans B

19. Which of the following salts can be prepared by a precipitation reaction?
You may wish to use the data booklet to help you.

  • A Barium sulfate
  • B Lithium nitrate
  • C Calcium chloride
  • D Ammonium phosphate

Ans A

20. A solution of accurately known concentration is more commonly known as a

  • A correct solution
  • B precise solution
  • C standard solution
  • D prepared solution.

Ans B

 

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