Question

You are given the following materials:
(A) marble chips
(B) dilute hydrochloric acid
(C) Zinc granules
Identify the type of reaction when marble chips and Zinc granules are added separately to acid taken in two test tubes.

Answer 1

Hint: A dilute acid is an acid in which concentration of water mixed in acid is higher than the concentration of acid itself, that is there is more volume of water compared to the volume of acid itself. One of the reactions involves a base and the other involves the liberation of hydrogen gas.

Complete step by step solution:
Most of the parts of marble chips are made of calcium carbonate, which is an alkaline compound. Being alkaline marble chips react with hydrochloric acid to produce calcium chloride, water and carbon dioxide. Calcium chloride is white in colour and carbon dioxide is colorless.
When zinc is converted into solid crystals it is called zinc granules. Zinc is a chemical element of group 12. Zinc had an atomic number as thirty. Zinc is slightly brittle at room temperature and it has blue-silvery appearance when oxidation is removed. Zinc reacts easily with dilute hydrochloric acid to produce bubbles which are of hydrogen atom. It is a single displacement type of reaction.
A displacement reaction is a reaction in which an element in a compound gets displaced by another more reactive element, to form a new compound.
So, when marble chips are added to dilute hydrochloric acid, they undergo neutralization reaction and when zinc granules are added in dilute hydrochloric acid, they undergo displacement reaction.

Note:
Neutralization reaction is a reaction in which acid and base react and neutralizes each other to give salt and water.
Displacement reaction is a chemical reaction in which a more active or reactive element displaces a less reactive or active element from its own compound.