A set of four stages for preparing a soluble salt from a dilute acid and a solid metal oxide is given below. 1 Heat the dilute acid. 2 Evaporate the solution until it is reduced to half its volume, then leave it to cool. 3 Add an excess of metal oxide. 4 Filter off any solid that has not reacted. Which sequence is correct for these stages?
- A$1 \rightarrow 2 \rightarrow 3 \rightarrow 4$
- B$1 \rightarrow 3 \rightarrow 4 \rightarrow 2$
- C$3 \rightarrow 1 \rightarrow 2 \rightarrow 4$
- D$3 \rightarrow 4 \rightarrow 1 \rightarrow 2$