In 630 ml of a 20% solution of nitric acid with a density of 1.12 g / ml, 126 g of this acid was added

| February 21, 2021 | education

In 630 ml of a 20% solution of nitric acid with a density of 1.12 g / ml, 126 g of this acid was added, find the mass fraction of the acid in the resulting solution.

1. Find the mass of the initial solution by the formula:

m = p * V = 1.12 * 630 = 728 g

2. Find the mass of the solute by the formula:

m (in-islands) = m (solution) * w (solution) / 100% = 728g * 20% / 100% = 145.6 g HNO3

When 126 g of HNO3 was added, the mass of the solution and the mass of HNO3 in the solution changed.

3. Find the total mass of the acid:

145.6 + 126 = 271.6 g

4. Find the total mass of the solution:

728 + 126 = 854 g

5. We calculate the mass fraction of acid in the resulting solution by the formula:

w (solution) = m (solution in-va) * 100% / m (solution) = 271.6 * 100/854 = 31.8%.



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