For the reaction C + 2H2 -> CH4

Question

How many grams of hydrogen are required to produce 145 grams of methane, CH4

Answer 1

1. Write and balance the equation. You have that.

2. mols CH4 = grams/molar mass = ?

3. Using the coefficients in the balanced equation, convert mols methane to mols H2. For every mols CH4 you will need 2 mols H2.

4. Now convert mols H2 to grams H2.
grams H2 = mols H2 x molar mass H2 = ?

This 4 step procedure works for all stoichiometry problems. With a slight modification it works on limiting regent problems also.

Answer 2

18.3