When 96 grams of water are produced how many grams of hydrogen must react according to the equation 2h2+o2 react to form 2h2o?

  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

Ibelieve your answer is true 

Olá. porque a reação na temperatura é muito rapida a do copo : )