Question

CHEM HELP!

using the average atomic mass, calculate the number of atoms present in 1.2 mL of liquid mercury.
(Density=13.6g/mL)

Answer 1

So let's convert this amount of mL to grams:

$\frac{13.6g}{1mL}*1.2mL=16.32g$

Then we need to convert to moles using the molar weight found on the periodic table for mercury (Hg):

$\frac{1mole}{200.59g}*16.32g=8.135*10^{-2}mol$

Then we need to convert moles to atoms using Avogadro's number:

$\frac{6.022*10^{23}atoms}{1mole} *[8.135*10^{-2}mol]=4.90*10^{22}atoms$

So now we know that in 1.2 mL of liquid mercury, there are $4.90*10^{22}atoms$ present.