How much hydrogen can be obtained by interacting with water and 1.4 calcium?

m (Ca) = 1.4 g.
Let us determine the volume of hydrogen that will be obtained as a result of the reaction. We write down the equation of reactions first.
Ca + 2HOH = Ca (OH) 2 + H2.
First, we find the amount of calcium, use the following formula.
n = m / M.
M (Ca) = 40 g / mol.
n (Ca) = 1.4 / 40 = 0.035 mol.
We find the amount of hydrogen substance by the reaction equation.
0.035 mol Ca – x mol H2
1 mol Ca – 1 mol H2
X = 0.035 * 1: 1 = 0.035 mol H2.
Find the volume of hydrogen.
n = V / Vm.
V = n * Vm = 0.035 * 22.4 = 0.784 liters.
Answer: V = 0.784 l.