Calculate the mass of sodium oxide that forms when 20 grams of sodium reacts with oxygen.

m (Na) = 20 g.
Determine the mass of sodium oxide. We write down the resulting solution.
First, we write down the equation of reactions.
2Na + O2 = 2Na2O
First, we calculate the molar mass of sodium and sodium oxide. We get the following.
M (Na) = 23 g / mol.
M (Na2O) = 2 * 23 + 16 = 46 + 16 = 62 g / mol.
Further, according to the reaction equation, we find the mass of sodium oxide. We get the following.
20 g sodium – x g sodium oxide
2 * 23 g / mol sodium – 2 * 62 g / mol sodium oxide
Find the unknown value of x.
X = 20 * 2 * 62: (23 * 2) = 54 g Na2O.
The result is a mass of sodium oxide equal to 54 grams.
Answer: m (Na2O) = 54 g.