Find the mass of KNO₃ required to produce 126 kg of nitric acid. Find whether a larger or smaller mass of NaNO₃ is required for the same purpose.

KNO₃ + H₂SO₄ ⟶ KHSO₄ + HNO₃

NaNO₃ + H₂SO₄ ⟶ NaHSO₄ + HNO₃

$\begin{matrix} \text{KNO}$3 & + &\text{H}2\text{SO}4 & \longrightarrow & \text{KHSO}4 & + \text{HNO}_3 \ 39 + 14 + 3(16) & & & & & 1 + 14 + 3(16) \ = 39 + 14 + 48 & & & & & = 1 + 14 + 48 \ = 101 \text{ g} & & & & & = 63 \text{ g} \end{matrix}

63 g of HNO₃ is formed by 101 g of KNO₃

∴ 126000 g of HNO₃ is formed by $\dfrac{101}{63}$ x 126000
= 202000 g = 202 kg

Similarly,

$\begin{matrix} \text{NaNO}$3 & + &\text{H}2\text{SO}4 & \longrightarrow & \text{NaHSO}4 & + \text{HNO}_3 \ 23 + 14 + 3(16) & & & & & 1 + 14 + 3(16) \ = 23 + 14 + 48 & & & & & = 1 + 14 + 48 \ = 85 \text{ g} & & & & & = 63 \text{ g} \end{matrix}

63 g of HNO₃ is formed by 85 g of NaNO₃

∴ 126000 g of HNO₃ is formed by $\dfrac{85}{63}$ x 126000
= 170000 g = 170 kg

So, a smaller mass of NaNO₃ is required.