Question

Given the following equation: 2h20=2h2+02 how many grams of o2 are produced if 3.6 grams of h20 react?

Answer 1

Answer:

3.2 g O₂

Explanation:

To find the mass of O₂, you need to (1) convert grams H₂O to moles H₂O (via molar mass), then (2) convert moles H₂O to moles O₂ (via mole-to-mole ratio from reaction coefficients), and then (3) convert moles O₂ to grams O₂ (via molar mass). It is important to arrange the ratios/conversions in a way that allows for the cancellation of units (the desired unit should be in the numerator). The final answer should have 2 sig figs to reflect the sig figs of the given value (3.6 g).

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

Molar Mass (H₂O): 18.014 g/mol

2 H₂O -----> 2 H₂ + 1 O₂

Molar Mass (O₂): 2(15.998 g/mol)

Molar Mass (O₂): 31.996 g/mol

3.6 g H₂O         1 mole               1 mole O₂           31.996 g
----------------  x  ---------------  x  ---------------------  x  ---------------  = 3.2 g O₂
                         18.014 g          2 moles H₂O          1 mole