What is the mass of a mole of Ca(OH)2?

This is basically calculating together the atomic masses of each individual atoms and adding them together to give the formula's mass. Ca = 20 O = 8 H = 1 Deducing these from the Periodic Table, we add them together (be sure to multiply the Hydrogen atom by 2 as we have two atoms of it in the formula initially). So, => 20 + 8 + (1x2) = 30. There you go =]..........