Mole Conversions

The above diagrams shows The conversion steps between Grams, Moles and Particles.

Now we are going to try to apply these:

(Remember sig figs!!)

ex/ How many moles of CCl4 are present in 8.36 x 10^35 molecules of CCl4?

Particle/Atom/Formula Unit ---> Moles

8.36 x 10^35 x 1/6.022 x 10^23 = 1.39 x 10^12 moles

ex/ How many copper atoms are present in 3.1 x 10^-3 mole of Cu2SO4

Moles ---> Particle/Atom/Formula Unit

Here it gets a little tricky, you are asked to find the number of copper atom, but it is Cu2, therefore you're gonna have to times 2 to get your final result.

3.1 x 10^-3 x 6.022 x 10^23 x 2 = 3.7 x 10^21 copper atoms

ex/ What is the mass in grams of 6.663 moles of neon gas?

Moles ---> Grams

Molecular mass of Ne2 = 2 Ne x 20.2 = 40.4 u

Molar mass of Ne2 = 40.4 g/mole

6.663 x 40.4 g/mole = 269 g Ne2

ex/ How many moles are there in 92.0 grams of Lead?

Grams ---> Moles

Atomic mass of Pb = 207.2 u

Molar mass of Pb = 207.2 g/mole

92.0 x 1/207.2 = 0444 mol Pb