1 Mole of a Substance Contains 6.02X1023 Particles

Mole Concept Notes

Avagadro’s Number

1 mole of a substance contains 6.02x1023 particles

Particles are called atoms if you are talking about an element molecules if you are talking about a covalent compound formula units if you are talking about ionic compounds

Ex: 1 mole of Fe = 6.02x1023 atoms 23 1 mole of H2O = 6.02x10 molecules 1 mole of NaCl = 6.02x1023 formula units

Review: A conversion factor is a two part unit that has a per relationship. Ex: miles per hour, hours per day

6.02x1023 particles/mole = Avogadro’s number

Avagadro’s number is a conversion factor where you can convert particles to moles, or moles to particles!!!

__ 6.02x10 23 particles___ or __ 1 mole______1 mole 6.02x1023 particles

Ex: What is the number of atoms in 0.500 mole of Al?

0.500moles 6.02x10 23 atoms of Al = atoms of Al 1 mole

Ex: What is the number of moles of S in 1.8 x 1024 S atoms?

Molar Mass - that mass of one mole of any substance - found on the periodic table – atomic mass! amu=g/mole - round molar mass to two decimal places

Ex: 1 mole of Br atoms = 79.90amu = 79.90g/mole

For compounds add the atomic masses of all the atoms in compound!

Ex: 1 mole of H2O = 1.00794 + 1.00794 + 15.999 = 18.01g/mole Molar Mass is another conversion factor to use in this chapter! you can convert from grams to mole and moles to grams!

Ex: How many grams of Al are in 3 moles of Al?

__3 moles of Al______26.98 g____ = g of Al 1 mole

The molar mass of Al (26.98g/mole) was found on the periodic table!

Ex: The artificial sweetener aspartame (Nutra-Sweet) formula C14H18N2O5 is used to sweeten diet foods, coffee and soft drinks. How many moles of aspartame are present in 225 g of aspartame? (Hint: first you have to add all the atomic masses of all the atoms in aspartame to get your molar mass)