Question

Using Dimensional Analysis, how many moles of sodium is 32.5 g of sodium?

Could you please tell me the steps on how to solve this I am stumped.

Answer 1

Dimensional analysis is just fancy words for keeping up with your units. This is how this problem would be done.

32.5g Na * (1mol Na)/(22.9898g Na) = 1.41 mol Na

Here is a skeleton calc to show you what is going on:

(g Na) * (mol Na)/(g Na) = mol Na

Since we started with (g Na) and we want to know (mol Na) I created a conversion factor that would make the (g Na) cancel out and leave us with (mol Na) only. The conversion factor is:

1 mol Na = 22.9898 g

Hope this helps.

Answer 2

Thanks a lot.