How many grams of sodium hydroxide can be obtained from 2 grams of sodium and 50 grams of water?

Given:
m (Na) = 2 g
m (H2O) = 50 g

To find:
m (NaOH) -?

Decision:
1) Write the reaction equation:
2Na + 2H2O => 2NaOH + H2;
2) Calculate the amount of sodium substance:
n (Na) = m (Na) / M (Na) = 2/23 = 0.1 mol;
3) Calculate the amount of water substance:
n (H2O) = m (H2O) / M (H2O) = 50/18 = 2.8 mol;
4) Determine the amount of sodium hydroxide substance:
n (NaOH) = n (Na) = 0.1 mol;
5) Calculate the mass of sodium hydroxide:
m (NaOH) = n (NaOH) * M (NaOH) = 0.1 * 40 = 4 g.

Answer: The mass of NaOH is 4 g.