Question

the density of Hg is 13.54 g/mL. When 15.6 mL are placed in a graduated cylinder, How many moles of Hg are there in the graduated cylinder? and How many Hg are there in the graduated cylinder?

Answer 1

First step is to know how many grams of Hg are there in the cylinder.
That's going to be the density multiplied by the volume and you're going to get 211.224 g

Answer 2

Then the next step is to know the Atomic Mass of Hg, that is given by 200.59 g/mol.

Answer 3

Then to know the number of moles of Hg in the cylinder, simply divide the mass by the atomic mass and you'll get 1.053 moles