How do you prepare a soluble salt in the required practical?

To prepare a soluble salt in the required practical, you need to perform an acid-base reaction and then crystallise the salt.

In more detail, the first step is to choose an acid and a base that will react to form the desired salt. For example, if you want to make copper sulfate, you could react sulfuric acid with copper oxide. The general equation for this type of reaction is acid + base -> salt + water.

Start by gently heating the acid in a beaker. Then, add the base a little at a time, stirring continuously. Be careful not to add too much base at once, as this can cause the mixture to bubble over. Continue adding the base until no more will dissolve. This is the point at which the acid has been neutralised.

Next, filter the mixture to remove any excess base. This will leave you with a solution of the salt in water. To crystallise the salt, gently heat the solution to evaporate some of the water. Then, leave it to cool. As it cools, the salt will start to form crystals.

Once the crystals have formed, you can filter them out of the solution. Rinse them with a little cold water to remove any remaining impurities, then leave them to dry.

Remember to always wear safety goggles and gloves when handling acids and bases, and to work in a well-ventilated area. Also, be aware that the process of crystallisation can take some time - it's not something you can rush.

In summary, preparing a soluble salt involves reacting an acid with a base, filtering out any excess base, and then crystallising the salt from the solution. It's a straightforward process, but one that requires care and patience.