Chemistry – GSCE/ exam formed questions (PAPER 1)

Explain why Copper oxide (CuO) has a high melting point. [3]

• a lot of enrrgy required to break bonds

• which are between the opposietly charged ions

Explain why water (H²O) has a low boiling point? [3]

• little energy is required to break bonds

• weak intermolecular forces

• small molecules

why does solid sodium chloride not conduct electricity?

ions are not free to move

which ion makes a solution acidic?

H+

The student investigated the volume of CO² produced with different masses of calcium carbonate react with hydrochloride acid. describe a method he could use. [6]

• measure certain mass of calcium carbonate using a balance

• transfer mass of calcium carbonate to flask

• measure certain volume of hydrochloric acid using a cylinder

• add acid to flask and attach bung

• record volume of gas produced in a specific amount of time

• repeat investigation with different mass of calcium carbonate to calculate a mean

IV = mass of calcium carbonate

DV = volume of gas

CV = volume of acid

Explain what happens to sodium atoms and to oxygen atoms when sodium reacts with oxygen to produce sodium oxide (NA²O) [4]

• sodium atoms lose one electron

• oxygen atom gains two electrons

• two sodium atoms form an ionic bond with one oxygen atom

give two observations seen during a reaction.

• yellow flame

• white smoke