Question

A crucible containing an unknown mass of magnesium weighs 37,63 if the mass of the empty crucible was found to be 32.83 determine the number of moles of magnesium

Answer 1

m(crucible + Mg) = 37.63 g;

m(crucible) = 32.83 g;

So, m(Mg) = m(crucible + Mg) - m(crucible) = 37.63 - 32.83 = 4.8 g;

M(Mg) = 24 g/mol;

n(Mg) = m(Mg)/M(Mg) = 4.8/24 = 0.2 mol.

Answer: 0.2 mol.