Question

The density of Hg is 13.6g/cm^3. How many Hg atoms are present in 10.0cm^3 of Hg?

I think the size of an atom is 6.22 x 10^23. The answer is 4.08 x 10^23. I need help getting to the answer.

Answer 1

13.6 g Hg/cm^3 * 10 cm^3 The cm^3 cancels out and you get 136 g Hg.

136 g Hg * 200.59 g Hg/ 1 mol Hg = 0.68 mol Hg.

0.68 mol Hg * 6.02*10^23 atoms Hg/ 1 mol Hg= 4.08*10^23 atoms Hg

Answer 2

I did your other one.

Answer 3

Two minor problems with the answer ffrom Ana.
136 x (1 mol/200.59) = 0.68 mole [the fraction is the reciprocal is problem 1) and the second is I would have carried the number out to 0.678 since you are allowed 3 significant figures.)
Then 0.678 x 6.022 x 10^23 = ??

Answer 4

Thankyou both very much.