[millerst]

Hi All,

I've missed a lot of class because of appointments and stuff and I'm not sure how to go about doing this question.

Determine the mass of each sample.

a) 6.02 x 10²⁴ formula units of ZnCl₂

So how I went about it was first finding the answer:

1) 6.02 x 10²⁴ x 6.02 x 10²³
2) Then multiply the answer from 1 times the molar mass of Zinc Chloride to get the mass

BUT FOR SOME REASON THIS ISN’T HOW YOU DO IT BECAUSE THE ANSWER IS WRONG.
CAN SOMEONE HELP ME WITH THIS QUESTION.

Thanks Stefan

[Borek]

1) 6.02 x 10²⁴ x 6.02 x 10²³

What are you trying to do here?

[millerst]

What are you trying to do here?

Multiply by the Avogadro Constant... you don't do that?

[allanf]

I imagine you'd want to divide by it (to get the moles)

[exec]

Avogadro constant = number of atoms in 12g of Carbon-12 = in 1 mole of substance.

In one mole of ZnC_l2, there are 6.02x10²³ of molecules.

So you should divide.