Question

27. For the reaction 2 H2 + O2 → 2 H20, how

many moles of H2O would you get from 2.0169
H2?
a. 2.016 mol H2O b. 1 mol H2O
c. 2 mol H2O
d. 4 mol H2O

Answer 1

2H₂ + O₂ → 2H₂O

You will need to use stoichiometry to solve this problem. The stoichiometric factor will need to relate H₂ and H₂O. From the equation, we see that for every two H₂ molecules that react, two H₂O molecules are produced, so the factor is
`(2H_(2) O)/(2H_(2) )`. The twos reduce, making this a one-to-one ratio.

`2.0169molH_(2) ((2molH_(2) O )/(2molH_(2) ) )=2.0169molH_(2) O`

Answer:

a. 2.016 mol H₂O

Hint: Because of significant figures, the other three answers would be wrong by default.