The grams of water needed to react with 44.9 grams of Li2O is calculated as follows
write the equation for reaction
Li2O +H2O = 2LiOH
find the moles of Li2O = mass/molar mass
= 44.9/29.9 = 1.5 moles
by use of reacting ratio between Li2O to H2O which is 1:1 the moles of H2O is therefore = 1.5 moles
mass is therefore = moles x molar mass
= 1.5 mol x 18 g/mol = 27 grams
