What volume of hydrogen will be released when 8.1 g of aluminum is dissolved in H2O?

Let’s execute the solution:
1. Let’s compose an equation, select the coefficients:
2Al + 6H2O = 3H2 + 2Al (OH) 3 – redox reaction, hydrogen is released;
2. Let’s make the calculations:
M (Al) = 26.9 g / mol;
M (H2) = 2 g / mol.
3. Let us calculate the number of moles of aluminum, if the mass is known:
Y (Al) = m / M = 8.1 / 26.9 = 0.3 mol.
4. Let’s make the proportion:
0.3 mol (Al) – X mol (H2);
– 2 mol -3 mol from here, X mol (H2) = 0.3 * 3/2 = 0.45 mol.
5. Find the volume of hydrogen:
V (H2) = 0.45 * 22.4 = 10.08 liters.
Answer: Hydrogen was obtained with a volume of 10.08 liters.