Remember: Put answers in the correct number of sigfigs.
1) Converting between particles <--> moles. In this conversion, we use Avogrado's number.
a) Particles --> moles
# of particles x 1 mol = # of moles
6.022x10^23particles
Ex. If there are 3.01 x 10^24 C particles, how many moles are there?
3.01 x 10^24 C particles x 1 mol = 5.00 moles of C
6.022 x 10^23 particles
b) Moles --> particles
Another example:
If there are 0.75 mole of CO2, how many molecules are there?
0.75 moles CO2 x 6.022 x 10^23 particles = 4.5 x 10^23 molecules of CO2
1 mole
Now that you know how many molecules are in CO2, how many atoms of Oxygen are there?
4.5 x 10^23 molecules CO2 x 2 atoms of Oxygen = 9.0 x 10^23 atoms of O
1 molecule of CO2
a) Moles--> grams
# of moles x molar mass = # of grams
1 mole
Note: To find the molar mass, look at the periodic table for the atomic mass.
Ex. If there are 2.04 moles of Carbon, what is the mass?
2.04 moles x 12.0 g = 24.5 g of Carbon
1 mole
b) Grams --> moles
# of grams x 1 mole = # of moles
molar mass
Ex. If there is 3.45 g of Carbon, how man moles are present?
3.45 g x 1 mole = 0.288 mole of Carbon
12.0 g
Another example: If there are 6.2 g of MgCl2, how many moles are present?
6.2 g x 1 mole = 0.065 mole of Mg Cl2
95.3 g
Whewww, that's a lot of info..time for a chem joke!
What does Avogrado put in his hot chocolate?
Marsh-mole-ows!
KEKEKE. ;P
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