chem: preparing soluble salts

step 1

add excess metal oxide to the acid

step 2

gently warm the mixture

why is the metal oxide added in excess

to ensure all the acid has reacted

step 3

filter the solid from the solution

why do you warm the mixture?

to speed up the reaction

step 4

heat the filtered solution

why do you filter the solid from the solution?

to remove the unreacted solid from the solution

step 5

leave the solution to evaporate water slowly

why do you heat the solution?

to evaporate water and concentrate the salt solution

why do you leave the solution to evaporate?

for crystallisation to occur