Given the unbalanced equation: N2 (g) + H2 (g) → NH3 (g)

When the equation is balanced using the smallest whole-number coefficients, the ratio of moles of hydrogen consumed to moles of ammonia produced is

1) 1:3

2) 2:3

3) 3:1

4) 3:2

Option-4 (3:2) is the correct answer.

Explanation:

Following steps are taken to balance the given unbalanced chemical equation.

Step 1: Write the unbalanced chemical equation,

N₂ + H₂ → NH₃

Step 2: Balance Nitrogen Atoms;

There are 2 nitrogen atoms on left hand side and 1 nitrogen atoms on right hand site therefore, to balance them multiply NH₃ on right hand side by 2 i. e.

N₂ + H₂ → 2 NH₃

Step 3: Balance Hydrogen Atoms;

Now, there are 2 hydrogen atoms on left hand side and 6 hydrogen atom on right hand site therefore, to balance them multiply H₂ on left hand side by 3 i. e.

N₂ + 3 H₂ → 2 NH₃

Now, the equation is balanced.

Step 4: Finding out mole ratios:

From balanced chemical equation it can be concluded that 3 moles of H₂ are involved in producing 2 moles of NH₃ hence, the mole ratio of consumption of H₂ to production of NH₃ is 3:2.