# Determine the volume of hydrogen required to replace all copper from a 640 mg sample

Determine the volume of hydrogen required to replace all copper from a 640 mg sample of copper oxide (two) containing 25% impurities.

Divalent copper oxide is reduced with hydrogen gas when heated. This synthesizes metallic copper and water. The reaction is described by the following chemical reaction equation:

CuO + H2 = Cu + H2O;

Cupric oxide reacts with hydrogen in equal (equivalent) molar amounts. In the course of the reaction, the same equal chemical amounts of copper and water are synthesized.

Let’s find the chemical amount of copper oxide.

For this purpose, we divide the weight of the oxide by the weight of 1 mole of oxide.

M CuO = 64 + 16 = 80 grams / mol;

N CuO = 0.64 x 0.75 / 80 = 0.006 mol;

Thus, it is possible to carry out the reduction of 0.06 mol of copper oxide and obtain 0.006 mol of copper.

The same amount of hydrogen will be required. Let’s calculate the volume of hydrogen. To do this, multiply the molar amount of the substance by the volume of 1 mole of gas (22.4 liters).

N H2 = 0.006 mol;

V H2 = 0.006 x 22.4 = 0.1344 liters; One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.