Cambridge IGCSE Chemistry Quiz

A gas is heated. The pressure is kept constant. Which statement describes the behaviour of the particles in the gas?

• The particles move faster and become closer together.

• The particles move faster and become further apart.

• The particles move more slowly and become closer together.

• The particles move more slowly and become further apart.

A mixture of ice and water is left to stand and the ice melts. Which row describes what happens as the ice is melting?

• energy change temperature of mixture average kinetic energy of particles decreases increases

• energy is used to overcome attractive forces increases

• average kinetic energy of particles decreases stays the same

• energy is used to overcome attractive forces stays the same

Hydrogen chloride gas [Mr: HCl, 36.5] is released at P in the apparatus shown. The universal indicator paper turns red after 38s. The experiment is repeated using sulfur dioxide gas [Mr: SO2, 64]. What is the result for sulfur dioxide gas?

• 26 blue

• 51 blue

• 26 red

• 51 red

Four statements about atoms are listed. The centre of an atom is positively charged. Protons and electrons are located in the nucleus. Protons and electrons have the same mass. Most of the mass of an atom is in the nucleus. Which statements are correct?

• 3 and 4

• 2 and 3

• 1 and 4

• 1 and 2

The electronic configurations of two elements are given. element L: 2,8,8,1 element M: 2,8,4 Which row identifies the group number and the period number for element L and element M?

• element M element L period number group number period number group number 3 IV 4 I

• 4 III 4 I

• 4 III 1 IV

• 3 IV 1 IV

Which statement explains why isotopes of the same element have the same chemical properties?

• They have different numbers of protons in their nucleus.

• They have different numbers of neutrons in their nucleus.

• They have the same electronic configuration.

• They have the same number of electrons as protons.

Which statements about potassium chloride are correct?

• It conducts electricity when solid because its ions are free to move.

• It has a high melting point because it has strong intermolecular forces.

• Its structure is a giant lattice of alternating positive and negative ions.

• It is soluble in water.

How many electrons are shared in one molecule of nitrogen and in one molecule of ethene?

• 12

• 8

• 6

• 2

What is the total number of electrons in one molecule of ammonia, NH3?

• 11

• 10

• 8

• 6

When heated, copper(II) oxide, CuO, reacts with ammonia, NH3. 3CuO + 2NH3 → 3Cu + N2 + 3H2O 8.5g of ammonia reacts with an excess of copper(II) oxide to produce 26.4g of copper. What is the percentage yield of copper in this reaction?

• 82.5%

• 55.0%

• 32.2%

• 27.5%