Find the mass and amount of oxygen, which reacts with 46 grams of sodium.

1. Let’s write down the reaction equation:

All alkali metals except lithium form peroxides with oxygen.

2Na + O2 = Na2O2.

2. Find the amount of reacted sodium:

n (Na) = m (Na) / M (Na) = 46 g / 23 g / mol = 2 mol.

3. According to the reaction equation, we find the amount and then the mass of oxygen:

n (O2) = n (Na) / 2 = 2 mol / 2 = 1 mol.

m (O2) = n (O2) * M (O2) = 1 mol * 32 g / mol = 32 g.

Answer: n (O2) = 1 mol; m (O2) = 32 g.