# How many grams of oxygen can be obtained by decomposition of 245 g of berthollet’s salt?

January 28, 2021 | education

| Given:

m (KClO3) = 245 g

To find:

m (O2) -?

Decision:

1) Write the reaction equation:

2KClO3 => 2KCl + 3O2 ↑;

2) Calculate the molar masses of KClO3 and O2:

M (KClO3) = Mr (KClO3) = Ar (K) * N (K) + Ar (Cl) * N (Cl) + Ar (O) * N (O) = 39 * 1 + 35.5 * 1 + 16 * 3 = 122.5 g / mol;

M (O2) = Mr (O2) = Ar (O) * N (O) = 16 * 2 = 32 g / mol;

3) Calculate the amount of KClO3 substance:

n (KClO3) = m (KClO3) / M (KClO3) = 245 / 122.5 = 2 mol;

4) Determine the amount of substance O2:

n (O2) = n (KClO3) * 3/2 = 2 * 3/2 = 3 mol;

5) Calculate the mass of O2:

m (O2) = n (O2) * M (O2) = 3 * 32 = 96 g.

Answer: The mass of O2 is 96 g.

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.