How many grams of sodium sulfide will be obtained when 64 g sulfur reacts with sodium?

Let’s write the reaction equation:

2Na + S = Na2S

Let’s find the amount of sulfur substance:

v (S) = m (S) / M (S) = 64/32 = 2 (mol).

According to the reaction equation, 1 mole of Na2S is formed per 1 mole of S, therefore:

v (Na2S) = v (S) = 2 (mol).

Thus, it is possible to obtain sodium sulfide with a mass:

m (Na2S) = v (Na2S) * M (Na2S) = 2 * 78 = 156 (g).

Answer: 156