Question

Determine the number of atoms in 1.70 ml of mercury. (the density of mercury is 13.5 g/ml.)

Answer 1

To determine the number of atoms in 1.70ml of mercury, we have to determine the moles of mercury.

First find the mass in grams by using the formula:

Mass = volume x density

(1.70 mL Hg) x (13.5 g/mL) = 22.95 g Hg

Now find number of moles;

(22.95 g Hg) x (1 mol Hg/200.59 g/mol) = 0.1144 mol Hg

For number of atoms multiply with Avogardro's number that is 6.023 x 10²³

(0.1144 mol Hg) x (6.023 x 10²³ atoms/mol) = 6.89 x 10²² atoms Hg

So, there is 6.89 x 10²² atoms of mercury are present in 1.70ml of mercury.