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Chemistry CIE iGCSE:
Acids, Bases + Salts 2

Page 1



1. Which row in this table is the correct classification for magnesium oxide and sulfur dioxide?

  Magnesium oxide Sulfur dioxide
A acidic acidic
B acidic basic
C basic acidic
D basic basic
2. Aluminium oxide is amphoteric. This means that aluminium oxide would ...
  • A.   …react with acids but not bases
  • B.   …react with bases but not acids
  • C.   …not react with acids or bases
  • D. …react with both acids and bases
3. Which of the following substances would react with acid producing a salt?
  • A.   sodium chloride
  • B.   magnesium carbonate
  • C.   potassium nitrate
  • D.   copper(II)sulfate

An acid is a proton donor and a base is a proton acceptor.

4. Which substance is acting as an acid in the following reaction?

NH3(aq)  +  H2O(l) NH4+(aq)  +  OH-

  • A.   NH3
  • B.   H2O
  • C.   NH4+
  • D.   OH-
5. Which substance is acting as a base in the following reaction?

HCO3-(aq)  +  H2O(l) CO32-(aq)  +  H3O+(aq)

  • A.   HCO3-
  • B.   H2O
  • C.   CO32-
  • D.   H3O+
6. Which of the following groups of salts are ALL soluble?
  • A.   sodium chloride, potassium sulfate, lead(II)nitrate
  • B.   sodium chloride, silver chloride, lead(II)chloride
  • C.   potassium sulfate, barium sulfate, calcium nitrate
  • D.   potassium carbonate, calcium carbonate, copper(II)hydroxide
7. Dilute sulfuric acid and barium chloride solutions were mixed in a beaker producing a precipitate of calcium sulfate in a solution of hydrochloric acid.

Which equation for this reaction has the correct state symbols?

  • A.   BaCl2(aq)   +   H2SO4(aq) BaSO4(s)   +   2HCl(aq)
  • B.   BaCl2(aq)   +   H2SO4(l) BaSO4(s)   +   2HCl(l)
  • C.   BaCl2(s)   +   H2SO4(aq) BaSO4(aq)   +   2HCl(aq)
  • D.   BaCl2(s)   +   H2SO4(l) BaSO4(aq)   +   2HCl(l)

8. Which of the following would produce a precipitate when they are mixed together?

I. Sodium chloride and silver nitrate solutions
II. Copper(II)sulfate and sodium hydroxide solutions
III. Potassium carbonate and magnesium nitrate solutions
  • A.   I and II only
  • B.   I and III only
  • C.   II and III only
  • D.   I, II and III

9. Carbon dioxide gas is produced by adding dilute hydrochloric acid to marble chips (calcium carbonate).

CO2 gas collection using conical flask

If dilute sulfuric acid is used the bubbling stops almost immediately and no gas is collected.
The reason for this observation is ...

  • A. Carbon dioxide is soluble and dissolves in the water present
  • B. Calcium sulfate is insoluble  and deposits on the marble chip surface
  • C. Marble chips and sulfuric acid only form calcium sulfate and water
  • D. Sulfuric acid is a weaker acid than hydrochloric acid

Some soluble salts such as copper(II)chloride are prepared by adding excess insoluble solid to acid.

Copper chloride crystals
10. Why do you add excess of the insoluble solid?
  • A.   To ensure that a reaction takes place
  • B.   To speed up the reaction
  • C.   To allow the solid to be separated from the solution
  • D.   To ensure that all the acid is used up
11. Which technique is used to separate the excess insoluble solid from the reaction mixture?
  • A.   crystallization
  • B.   filtration
  • C.   precipitation
  • D.   titration