Question

If you burn 29.4 g of hydrogen and produce 263 g of water, how much oxygen reacted?

Answer 1

The reaction between hydrogen and oxygen to form water is given as:

$H_2 + O_2 \rightarrow H_2O$

The balanced reaction is:

$2H_2 + O_2 \rightarrow 2H_2O$

According to the balanced reaction,

4 g of hydrogen ($4\times 1$) reacts with 32 g of oxygen ($2\times 16$).

So, oxygen reacted with 29.4 g of hydrogen is:

$\frac{29.4\times 32}{4} = 235.2 g$

Hence, the mass of oxygen that is reacted with 29.4 g of hydrogen is 235.2 g.