Question

What is the mass in grams of 0.750 moles of `C_3H_8`?

Answer 1

Well what is the mass of one mole of propane.....?

Explanation:

Well, it's `44.1*g`, and how did we get this?

We take the sum....`3xx12.011*g*mol^-1(C)+8xx1.00794*g*mol^-1 (H)`; from where did I get the atomic masses? Did I know them off the top of my head? Do you have to learn them?

We have got a `0.750*mol` quantity, and to get its mass we take the product......

`0.750*molxx44.1*g*mol^-1~=30*g`