first we write the balanced chemical reaction:
C + 2 H2 -> CH4
*note that Hydrogen is diatomic in nature (that's why it's H2, not H)
then to get how much H2 reacted (in grams), we use the data of Carbon. 1 g of Carbon reacted, thus to get the number of moles of C, we divide 1 g by its molar mass (which is 12 g/mol)
1/12 = 0.0833 mol C
using the stoichiometric coefficients (number before the chemical symbol in the reaction) of the elements, we can relate the number of moles of C reacted to the number of moles of H2 reacted:
0.0833 mol C * (2 mol H2 / 1 mol C) = 0.1667 mol H2
then from the given, 0.33597 g of H is used. to convert this to grams of H2, we just divide 0.33597 by 2:
0.33597 g H / 2 = 0.167985 g H2
finally, to the the molar mass of H, we divide grams of H2 by moles of H2:
0.167985 / 0.1667 = 1.01 g/mol
hope this helps~ :)