Calculate what volume of oxygen can be obtained by decomposition of berthollet salt weighing 490 g.

1. Berthollet’s salt decomposes according to the equation:

2KClO3 = 2KCl + 3O2 ↑.

2. Let’s calculate the chemical amount of decomposing salt:

n (KClO3) = m (KClO3): M (KClO3);

M (KClO3) = 39 + 35.5 + 3 * 16 = 122.5 g / mol;

n (KClO3) = 490: 122.5 = 4 mol.

3. Determine the amount of oxygen released:

n (O2) = n (KClO3) * 3: 2 = 4 * 3: 2 = 6 mol.

4. Let’s calculate the volume of oxygen:

V (O2) = n (O2) * Vm = 6 * 22.4 = 134.4 liters.

Answer: 134.4 liters.