The number of grams of hydrogen that must react according to equation is 10.66 grams
2 H2 + O2 = 2H2O
calculation
find the number of moles of H2O reacted
that is moles = mass/molar mass
molar mass for water = 16 +(1 x2) = 18 g/mol
moles is therefore = 96 g/18 g/mol = 5.33 moles
by use of mole ratio between H2 to H20 which is 2:2 or 1:1 the moles of H2 is also = 5.33 moles
mass of H2 is = moles x molar mass of H2 = 1 x2 = 2g/mol
= 5.33 moles x 2 g/mol = 10.66 grams