In order to solve this problem you must have a clear understanding of dimensional analysis and moles, grams, amu, etc.
1. You always start with the Given!
1.24 mol H2O
2. Find the Molar Mass of H2O. You can do this by looking @ the periodic table
(1.008•2+16.00)=
18.016 g
3. Plug in your numbers and Solve!
1.24mol h20{18.016g}
{1molH2O}
You then multipy and will have gams of H2O in 1.24 mol.
22.3 g of H20