# Calculate the mass of a 10% calcium hydroxide solution required to react with 67.2

**Calculate the mass of a 10% calcium hydroxide solution required to react with 67.2 liters of carbon dioxide. How many grams of precipitate is formed?**

Ca (OH) 2 + CO2 = CaCO3 + H2O.

1) Find the amount of substance carbon dioxide. To do this, divide its volume by the molar volume: 67.2 / 22.4 = 3 mol.

2) According to the reaction equation, there is one mole of calcium hydroxide and one mole of calcium carbonate (precipitate) for one mole of carbon dioxide. This means that their amounts of substances are equal to 3 mol.

3) Molar mass of sediment: 40 + 12 + 48 = 100.

4) Sludge weight: 100 * 3 = 300g.

5) Molar mass of calcium hydroxide solution: 40 + 32 + 2 = 74.

6) The mass of calcium hydroxide in its solution is: 10 * 300/100 = 30g.

Answer: the mass of the sediment is 300 g, the mass of calcium hydroxide in its solution is 30 g.