**Step 1: Reaction**\n1. Measure a fixed volume of dilute hydrochloric acid into a beaker.\n2. Gently warm the acid using a Bunsen burner on a tripod and gauze.\n3. Add zinc carbonate powder slowly using a spatula, stirring with a glass rod, until no more fizzing is seen and some unreacted solid is left at the bottom. This is adding in excess.\n\n**Step 2: Filtration**\n4. Filter the mixture using a filter funnel and filter paper to remove the excess, unreacted zinc carbonate. The filtrate is zinc chloride solution.\n\n**Step 3: Crystallisation**\n5. Pour the filtrate into an evaporating basin.\n6. Heat the solution gently to evaporate about half of the water.\n7. Leave the concentrated solution in a cool place for crystals to form slowly.\n\n**Step 4: Drying**\n8. Once crystals have formed, pour off the remaining solution.\n9. Dry the crystals by patting them between filter papers or leaving them in a warm, dry place.
To make a soluble salt from an insoluble reactant, the following four-stage process is used:\n\n1. **Reaction:** The correct acid is needed to provide the chloride part of the salt, so **hydrochloric acid (HCl)** is used. Zinc carbonate is an insoluble solid. It is added to the acid until no more reacts (the fizzing stops) and there is solid left over. This is called adding in **excess** and ensures all the acid is neutralised. The reaction is: ZnCO₃(s) + 2HCl(aq) → ZnCl₂(aq) + H₂O(l) + CO₂(g).\n\n2. **Filtration:** The excess (unreacted) zinc carbonate must be removed from the zinc chloride solution. This is done by **filtration**. The zinc chloride solution passes through the filter paper as the **filtrate**.\n\n3. **Crystallisation:** To get solid crystals from the solution, most of the water must be removed. The filtrate is gently heated in an evaporating basin to evaporate about half the water, creating a saturated solution. This solution is then left to cool slowly. As it cools, the solubility of the zinc chloride decreases, and pure crystals form.\n\n4. **Drying:** The crystals are separated from the remaining liquid (e.g., by decanting or filtering) and then dried, for example, by patting with filter paper or in a low-temperature oven.
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