<span>22.2 grams
For every molecule of Al(C2H3O2)3, we have 9 atoms of hydrogen. So let's first determine how many moles of Al(C2H3O2)3 we have. So start by looking up the atomic weights of the elements involved.
Atomic weight aluminium = 26.981539
Atomic weight carbon = 12.0107
Atomic weight hydrogen = 1.00794
Atomic weight oxygen = 15.999
Molar mass Al(C2H3O2)3 = 26.981539 + (12.0107 * 2 + 1.00794 * 3 + 15.999 * 2)*3 = 204.111199
Moles Al(C2H3O2)3 = 500 g / 204.111199 g/mol = 2.449645107 mol
Moles H = 9 * 2.449645107 mol = 22.04680597 mol
Mass H = 22.04680597 mol * 1.00794 g/mol = 22.22185761 g
Rounding to 3 significant figures gives 22.2 grams.</span>
As the water vapor touches the mirror the particles of the vapor loses energy and they move less then the process Condensation takes place in which the gas turns into water.