What mass of salt can be obtained by dissolving 8.89 g of sodium hydroxide containing 10%

What mass of salt can be obtained by dissolving 8.89 g of sodium hydroxide containing 10% of insoluble impurities in nitric acid?

1. Let’s compose the reaction equation:

HNO3 + NaOH = NaNO3 + H2O.

2. Find the amount of sodium hydroxide:

ω (NaOH) = 100% – ω (impurities) = 100% – 10% = 90%.

m (NaOH) = (m (mixture) * ω (NaOH)) / 100% = 8.89 g * 90% / 100% = 8 g.

n (NaOH) = m (NaOH) / M (NaOH) = 8 g / 40 g / mol = 0.2 mol.

3. Using the equation, we find the amount and then the mass of sodium nitrate:

n (NaNO3) = n (NaOH) = 0.2 mol.

m (NaNO3) = n (NaNO3) * M (NaNO3) = 0.2 mol * 85 g / mol = 17 g.

Answer: m (NaNO3) = 17 g.