Question

When the following equation is balanced, the coefficient of H2O is Ca(s) + H2O + Ca(OH)2 + H2 a) 2

Answer 1

`Ca(s) + 2H_2O \rightarrow Ca(OH)_2 +H_2`

Step-by-step explanation:

Given:

In a balanced chemical equation, the number of atoms of each element are equal on both sides.

`Ca(s) + H_2O \rightarrow Ca(OH)_2 +H_2`

No. of atoms of Ca in left hand side = 1

No. of atoms of Ca in right hand side = 1

So, no. of atoms of Ca is balanced

Now,

No. of atoms of O in left hand side = 1

No. of atoms of O in right hand side = 2

Now multiply H2O with 2

`Ca(s) + 2H_2O \rightarrow Ca(OH)_2 +H_2`

No. of atoms of O are balanced on each side

No. of atoms of H in left hand side = 4

No. of atoms of H in right hand side = 4

Now, each element is balanced

So coefficient of H2O after balancing = 2