Calculate the volumes of hydrogen that can be obtained by the interaction of 6 g of calcium

Calculate the volumes of hydrogen that can be obtained by the interaction of 6 g of calcium (mass fraction of impurities 2%) with water.

Given:
m tech. (Ca) = 6 g
ω (approx.) = 2%

To find:
V (H2) -?

1) Write the reaction equation:
Ca + 2H2O => Ca (OH) 2 + H2 ↑;
2) Calculate the mass fraction of Ca:
ω (Ca) = 100% – ω (approx.) = 100% – 2% = 98%;
3) Calculate the mass of pure Ca:
m clean (Ca) = ω (Ca) * m tech. (Ca) / 100% = 98% * 6/100% = 5.88 g;
4) Calculate the amount of Ca substance:
n (Ca) = m pure. (Ca) / M (Ca) = 5.88 / 40 = 0.147 mol;
5) Determine the amount of substance H2:
n (H2) = n (Ca) = 0.15 mol;
6) Calculate the volume H2:
V (H2) = n (H2) * Vm = 0.15 * 22.4 = 3.36 liters.

Answer: The volume of H2 is 3.36 liters.