Question

2 H2 + O2 = 2H2O You have 20 grams of H, what's the mass of water?

Answer 1

2H2 + O2 —-> 2H2O

The mole ratio of H2 to H2O is 2 : 2 = 1:1

4 moles of H2 = 4 moles of H2O

Moles of H20 = 4mol

Molar mass of H2O = 18g/mol

Mass = moles X Molar mass

= 4mol x 18g/mol

= 72g

Mass of H2O is 72g