Determine the mass fraction of sodium hydroxide when dissolving 4.6 g of sodium in 150 g of water.

Let’s execute the solution:
1. According to the condition of the problem, we write down the equation:
m = 4.6 g. m = 150 g. W -?
2Na + 2H2O = 2NaOH + H2 – OBP, sodium hydroxide, hydrogen are released;
2. Calculations:
M (Na) = 22.9 g / mol;
M (NaOH) = 39.9 g / mol.
3. Determine the amount of the original substance:
Y (Na) = m / M = 4.6 / 22.9 = 0.2 mol;
Y (NaOH) = 0.2 mol since the amount of these substances according to the equation is 2 mol.
4. Find the mass of the product:
m (NaOH) = Y * M = 0.2 * 39.9 = 7.98 g.
5. Calculate the mass fraction of the output for the base:
W = m (substance) / m (solution) * 100;
W = 7.98 / 150 * 100 = 5.32%
Answer: The mass droll of the sodium hydroxide yield is 5.32%.