Question

Choose all the answers that apply.

Which of the following equations are balanced?

2H2 + O2 → 2H2O

2S + 3O2 → 2SO3

Li + Cl2 → LiCl

2K + 2H2O → H2 + 2KOH

2Fe + Cu(NO3)2 → 2Cu + Fe(NO3)2

Answer 1

2 and 3 are balanced as I see it
1 has onpy 2 hydrogen on the right and 4 on the left
4 has 2 copper on the right and 1 on the left

Answer 2

Answer : The balanced chemical equations are:

`2H_2+O_2\rightarrow 2H_2O`

`2S+3O_2\rightarrow 2SO_3`

`2K+2H_2O\rightarrow H_2+2KOH`

Explanation :

Balanced chemical reaction : It is defined as the reaction in which the number of atoms of individual elements present on reactant side must be equal to the product side.

(1) The given chemical reaction is,

`2H_2+O_2\rightarrow 2H_2O`

This reaction is a balanced chemical reaction because in this reaction the number of atoms of individual elements present on reactant side must be equal to the product side.

(2) The given chemical reaction is,

`2S+3O_2\rightarrow 2SO_3`

This reaction is a balanced chemical reaction because in this reaction the number of atoms of individual elements present on reactant side must be equal to the product side.

(3) The given chemical reaction is,

`Li+Cl_2\rightarrow LiCl`

This reaction is an unbalanced chemical reaction because in this reaction the number of chlorine atoms are not balanced.

In order to balance the chemical equation, the coefficient '2' put before the
`LiCl \text{and }Li` and we get the balanced chemical equation.

The balanced chemical reaction will be,

`2Li+Cl_2\rightarrow 2LiCl`

(4) The given chemical reaction is,

`2K+2H_2O\rightarrow H_2+2KOH`

This reaction is a balanced chemical reaction because in this reaction the number of atoms of individual elements present on reactant side must be equal to the product side.

(5) The given chemical reaction is,

`2Fe+Cu(NO_3)_2\rightarrow 2Cu+Fe(NO_3)_2`

This reaction is an unbalanced chemical reaction because in this reaction the number of iron and copper atoms are not balanced.

In order to balance the chemical equation, we are removing the coefficient '2' that present before
`Fe\text{and }Cu` and we get the balanced chemical equation.

The balanced chemical reaction will be,

`Fe+Cu(NO_3)_2\rightarrow Cu+Fe(NO_3)_2`