Question

Write balanced chemical equations involved in the following reactions:
a) Fluorine gas reacts with water.
b) Phosphine gas is absorbed in copper sulphate solution.

Answer 1

Hint: Balance chemical equation is that which has equal number of each element on reactant side and product side.
Fluorine gas reacts with water to give hydrogen fluoride and oxygen.
Phosphine gas reacts with copper sulphate to give cupric phosphide and sulphuric acid.

Complete step by step answer:
A chemical equation has two parts: one is reactant and other is product. When reactants react with each other under a suitable condition to give products, it is known as a chemical reaction, which is written symbolically by the chemical equation. A balanced chemical equation is one which has the same number of atoms of each element on the reactant and product side.
a) When fluorine gas reacts with water, it gives hydrogen fluoride (aqueous) and oxygen gas is evolved in the reaction. So, the balanced chemical equation will be,
\[2{F_2}(g) + 2{H_2}O(l) \to 4HF(aq.) + {O_2}(g)\]
Here, two moles of fluorine molecules react with two moles of water molecules to give four moles of hydrogen fluoride and one mole of oxygen. The number of atoms of fluorine, hydrogen and oxygen are the same on both reactant and product sides.
b) When phosphine gas is absorbed in copper sulphate solution, it gives black precipitate of cupric phosphide and sulphuric acid. So, the balanced chemical equation will be,
\[2P{H_3} + 3CuS{O_4} \to C{u_3}{P_2} + 3{H_2}S{O_4}\]
Here, the number of atoms of phosphorus, hydrogen, copper, sulphur and oxygen are the same on both sides of the reaction.

Note: The balancing of a chemical equation is governed by the law of conservation of mass.
From a balanced chemical equation, we can get the information regarding the amount of reactant needed for the chemical reaction and the product formed after the reaction.