Cambridge IGCSE Chemistry Quiz

Sodium chloride is a liquid at 900 °C. Which row describes the motion of the particles and the arrangement in sodium chloride at 900 °C?

• vibrate about a fixed point, regular

• move randomly, regular

• vibrate about a fixed point, random

• move randomly, random

Hydrogen chloride gas, HCl, reacts with ammonia gas, NH3, to form solid ammonium chloride. The apparatus is set up as shown. After a few minutes, a white cloud of solid ammonium chloride forms where the two gases meet. The experiment is repeated using hydrogen bromide gas, HBr, in place of hydrogen chloride. How far along the tube does the white cloud of solid ammonium bromide form?

• A

• B

• C

• D

Substances P and Q both conduct electricity. P is a mixture of two different types of atom. Q is made of only one type of atom. Which row describes Q and P?

• element, alloy

• compound, alloy

• alloy, compound

• element, compound

An atom of element R contains 15 protons, 16 neutrons and 15 electrons. What is R?

• gallium

• phosphorus

• sulfur

• zinc

Which molecule contains a double covalent bond between two atoms of the same element?

• carbon dioxide

• ethanol

• ethene

• nitrogen

Silicon(IV)oxide is a covalently bonded compound.

Which statements are correct? Choose two answers.

• Silicon atoms form four single bonds in silicon(IV)oxide.

• Oxygen atoms form two double bonds in silicon(IV)oxide.

• Silicon(IV)oxide has a high melting point.

• Silicon(IV)oxide contains one silicon atom and four oxygen atoms.

The equation for the reaction of iron(III) oxide with carbon monoxide is shown.

Fe₂O₃ + 3CO → 2Fe + 3CO₂

What is the percentage yield of iron when 16.8 g of carbon monoxide reacts completely with iron(III) oxide to form 8.96 g of iron?

• 80.0%

• 53.3%

• 40.0%

• 26.7%

What is the volume of 14.5 g of gaseous butane, C4H10, at room temperature and pressure?

• 96.0 cm3

• 6.0 cm3

• 96.0 dm3

• 6.0dm3

Aqueous copper(II)sulfate is electrolysed using copper electrodes.

Which statement describes what happens during the electrolysis?

• Copper atoms gain electrons at the cathode and copper(II)ions lose electrons at the anode.

• Electrons move in the external circuit from the positive electrode to the negative electrode.

• Copper(II)ions move through the electrolyte from the cathode to the anode.

• Copper is formed at the cathode and oxygen is formed at the anode.

Electrolysis is carried out on concentrated aqueous potassium bromide using inert electrodes.

Which products are formed at the cathode and anode?

• hydrogen, bromine

• potassium, bromine

• bromine, hydrogen

• potassium, hydrogen