4.2.3 Soluble Salts

To make soluble salts, acids can be reacted with solid insoluble substances such as metals, metal oxides, hydroxides, or carbonates. The process involves adding the solid substance to the acid until no further reaction occurs, and then filtering off any excess solid to obtain a solution of the salt. This solution can later be crystallised to produce solid salts.

To make pure, dry samples of named soluble salts, you can follow the following steps:

1. Gather the necessary materials: the acid, the solid substance, water, and any additional equipment such as a beaker, stirring rod, and filter paper.
2. Measure and add the appropriate amount of acid to a clean beaker. The specific quantity will depend on the desired concentration and the balanced equation for the reaction.
3. Slowly add the solid insoluble substance to the acid, while stirring continuously. Continue adding until no more reaction is observed, indicated by the absence of effervescence or gas evolution.
4. Filter the mixture to separate the excess solid from the salt solution. This can be done by using filter paper in a funnel or through other filtration methods.
5. Collect the filtered salt solution in a clean container.
6. To obtain solid salts, the salt solution can be crystallised. This can be achieved by allowing the solution to evaporate slowly under controlled conditions, such as in a crystallising dish or by using a heating apparatus. As the water evaporates, crystals of the salt will form.
7. Carefully collect the formed crystals and allow them to dry completely. This can be done by placing the crystals on filter paper or a clean, dry surface.