If 5.31 grams of H2 reacts according to the equation 3 H2 + N2 NH3, how many moles of NH3 are produced?

Question

Answer in units of moles 

Answer 1

Hello Chenoah.

 

The balanced equation for the reaction is:

 

3 H2 + N2 --> 2 NH3

 

You must balance the equation before you can calculate moles of product.

The balanced equation shows you that for every 3 moles of H2 you get 2 moles of NH3 (or ammonia).

 

Now, all we need to know is how many moles 5.31 grams of H2 is.

 

The molecular weight (MW) of H2 is just 2.016 g/mol (2 * 1.00794 = 2.01588 if you want to use more significant digits).

# of moles = mass in grams / MW 

So # of moles of H2 = 5.31g/2.016 g/mol = 2.63 moles, and

the # of moles of NH3 produced is 2.63 moles * 2/3 = 1.76 moles.

 

Hope this helps.

 

Andrew M