IGCSE/GCSE/ Chemistry -multiple choice questions.

A beaker containing solid carbon dioxide is placed in a fume cupboard at room temperature. The

carbon dioxide becomes gaseous.

Which process describes this change of state?

• Boiling

• condensation

• evaporation

• sublimation

Which statement about paper chromatography is correct?

• A solvent is needed to dissolve the paper.

• Paper chromatography separates mixtures of solvents.

• The solvent should cover the baseline.

• The baseline should be drawn in pencil.

Which statement explains why iodine is placed after tellurium in the Periodic Table?

• Iodine has fewer neutrons than tellurium.

• Iodine has fewer protons than tellurium.

• Iodine has more neutrons than tellurium.

• Iodine has more protons than tellurium.

Substance Q has a high melting point and conducts electricity both when molten and when

dissolved in water.

What is Q?

• calcium chloride

• diamond

• iron

• silver chloride

Elements X and Y form an ionic compound, XY.

In which group of the Periodic Table is X found and how is the bond between X and Y formed?

• Group-I ,by X gaining one electron from Y

• Group-1,by X transferring one electron to Y

• Group-VII, by X sharing electrons with Y

• Group-VII, by X transferring one electron to Y

Calcium phosphate forms when calcium chloride and sodium phosphate solutions react together.

x CaCl2 + y Na3PO4 → 2Ca3(PO4)2 + 12NaCl

Which values of x and y balance the equation?

• x y

  A 2 2

  B 3 4

  C 6 3

  D 6 4

• A

• B

• C

• D

Which substance does not use oxygen to produce heat energy?

• Carbon

• Nitrogen

• Natural gas

• Uranium

An energy level diagram for a reaction is shown above

Which statement about the reaction is correct?

• Heat is released.

• It is a combustion reaction.

• It is an endothermic reaction.

• The temperature increases.

Two reactions are done.

1 Hydrated cobalt(II) chloride is heated. It changes colour.

2 Water is added to the product of reaction 1. It becomes hotter. The original colour is produced.

Which types of reaction have occurred in reactions 1 and 2?

• A

• B

• C

• D

Which equation shows reduction of an iron compound?

• 4Fe + 3O2 → 2Fe2O3

• Fe + 2HCl → FeCl 2 + H2

• 4FeO + O2 → 2Fe2O3

• Fe2O3 + 3CO → 2Fe + 3CO2