Question

Given: 4Na + O2 → 2Na2O In this chemical reaction, how many moles of Na2O will be produced if 2.90 moles of Na react completely? Express your answer to three significant figures.

Answer 1

Since we already have the balanced equation, we know that the ratio between $Na:Na_{2}O$ is $4:2$ respectively.

So then we can set up a proportion to find the number of moles produced when 2.90 moles of Na react completely:

$\frac{4mol_{Na}}{2mol_{Na_{2}O}} =\frac{2.90mol_{Na}}{xmol_{Na_{2}O}}$

Then we cross multiply and solve for x:

$4x=5.8$

$x=1.45$

Therefore, we know that when 2.90 moles of Na react completely, there are 1.45 moles of $Na_{2}O$ that are produced.