How many grams of h2 would be formed if 34 grams of carbon reacted with an unlimited amount of h2o? the reaction is:
c + h2o co + h2
1) is this equation balanced?
2) what is the starting substance?
3) what is the ending substance that is asked for in the problem?
additional info: the atomic mass of c is 12.01 g/mole. the atomic mass of h2 is 2.016 g/mole.

1) The equation is already balanced;

Left side: 1C, 2H and 1O
Right side: 1C, 1O, 2H

2) Starting substances: water and carbon
There are two starting substances also called reactants. H2O which is a compound and C which is an element.

3) Ending substance asked for: H2.

This is hydrogen gas.

Stoichiometry:

1 mol of C produces 1 mol of H2

12.01 g of C productes 2.016 grams of H2

Ratio: 2.016 g of H2 / 12.01 g of C = X g of H2 /  34 g of C =>

x = 34 g of C* 2.016 g of H2 / 12.01 g of C= 5.707 g of H2