Chemistry 0620 · IGCSE · Elements, compounds and mixtures

Elements, compounds and mixtures — practice question

Cement is produced by heating clay together with limestone. Part of the limestone, which is calcium carbonate, decomposes to make calcium oxide and a gas that turns limewater milky.
(a(i))[2]

Complete the chemical equation for this reaction. $\text{CaCO}_3 \rightarrow [BLANK] + [BLANK]$

(a(ii))[1]

What type of chemical reaction is this?

(a(iii))[2]

Find the relative formula mass of calcium carbonate. Show your working clearly.

(b)[2]

State two differences between a compound and a mixture.

(c)[1]

Use the information in the table to suggest why concrete must be reinforced with steel when it is used to make bridges.

(d)[2]

Which two substances are needed for steel to rust?

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: CaO

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