Answer:
a) Zinc react with hydrochloric acid, it produces zinc chloride which is present in aqueous solution and hydrogen gas.
b) When calcium chloride react with sodium carbonate, it produces calcium carbonate (solid) and sodium chloride (liquid).
c) Sodium hydroxide react with hydrochloric acid, it produces sodium chloride (liquid) and water.
d) When calcium carbonate decompose, it forms calcium oxide which is present in solid form and carbondioxide gas.
