Chemistry 5070 · O Level · Formulae

Formulae — practice question

On heating zinc in air, it reacts with oxygen to produce an oxide. A student carries out an experiment to determine the formula of zinc oxide.
(a(i))[1]

Calculate the mass of zinc that was used in the experiment.

(a(ii))[1]

Calculate the mass of zinc oxide made.

(a(iii))[1]

Using your answers to (i) and (ii), calculate the mass of oxygen that combines with the zinc.

(a(iv))[2]

Using your answers to (i) and (iii), calculate the formula of zinc oxide. Show every step of your working. [$A_r$: Zn, 65; O, 16]

(b)[2]

When zinc reacts with dilute hydrochloric acid, a gas is released. Name the gas. Give a test and observation to identify the gas.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: 1.30 g

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI