Question

How many grams of water will be produced from 50 g hydrogen reacting with 50 g oxygen?

Answer 1

We need to first come up with a balanced equation:

$4H+O_{2}$ → $2H_{2}O$

We know that the molar ratio of hydrogen to oxygen to water now is 4:1:2.

Converting the amount of grams given to moles is as follows:

Hydrogen: $\frac{1mole}{1.008g}*50g=49.6mol$

Oxygen: $\frac{1mole}{15.999g}*50g=3.125mol$

We know now that the limiting reactant is oxygen. We can then know that the number of moles of water are produced are double the number of moles of oxygen used due to the ratio that we established at the beginning - 4:1:2.

So we now can use 6.25 moles of water as the amount produced.

Then we convert moles of water to grams:

$\frac{18.015g}{1mole} *6.25mol=112.59g$

Now we know that there are 112.59g of water produced when we start with 50g of hydrogen and 50g of water.