Question

The combustion of butane, `C_4H_10`, produces carbon dioxide water. When one sample of butane was burned, 4.46 grams of water was formed. How many grams of oxygen gas were consumed?

Answer 1

`"10.3 g O"_2`

Explanation:

Combustion reactions with hydrocarbons (compounds made up of only carbon and hydrogen, `C_4H_10`) involve the hydrocarbon reacting with `O_2` gas to form `H_2O` and `CO_2`

We must first balance the equation, we end up with;

`2C_4H_10 + 13O_2 -> 10H_2O + 8CO_2`

with the balanced equation, most of the work is done. We now simply convert from `H_2O` to `O_2` using the mol to mol ratios.

`H = "1.01 g"`
`O = "16.00 g"`
`H_2O = "18.02 g"`
`O_2 = "32.00 g"`

`"4.46 g H"_2"O" xx("1 mol H"_2"O")/("18.02 g H"_2"O") xx("13 mol O"_2)/("10 mol H"_2"O") xx ("32.0 g O"_2)/("1 mol O"_2) = "10.3 g O"_2" gas"`