Question

How many grams of water are made from the reaction of 16.0 grams of o2? given the reaction: 2h2 o2 --> 2h2o

Answer 1

Answer:

18.0 g H₂O

Explanation:

To find the mass of water (H₂O), you need to (1) convert grams O₂ to moles O₂ (via the molar mass), then (2) convert moles O₂ to moles H₂O (via mole-to-mole ratio from equation coefficients), and then (3) convert moles H₂O to grams H₂O (via the molar mass). It is important to arrange the conversions in a way that allows for the cancellation of units. The final answer should have 3 sig figs to match the sig figs of the given value.

Molar Mass (O₂): 2(15.998 g/mol)

Molar Mass (O₂): 31.996 g/mol

Molar Mass (H₂O): 2(1.008 g/mol) + 15.998 g/mol

Molar Mass (H₂O): 18.014 g/mol

2 H₂ + 1 O₂ -----> 2 H₂O

16.0 g O₂          1 mole            2 moles H₂O         18.014 g
---------------  x  ----------------  x  ---------------------  x  -----------------  = 18.0 g H₂O
                        31.996 g             1 mole O₂             1 mole