Counting of Atoms

Counting of Atoms Mole Avogadro’s number

I. ______a. Represented the number of protons and neutrons in an atom b. Reported in AMU’s i. Each unit having a mass of about 1.0 amu c. ______i. A unit used to represent the ______mass of a proton or neutron

II. The ______a. The same number of atoms in exactly ____ grams of carbon-12 b. The mole is the SI unit used for measuring the amount of a substance c. The mole is simply used as a ______.

III. ______a. The mass in grams of one mole of an element. i. Reported in ______b. The molar mass of 1 mole of anything is equal to the atomic mass of that element. i. Ex. 1. 1 mole of carbon has a molar mass of ______g 2. ___ moles of carbon has a molar mass of 24.0214g 3. 1 mole of Sodium has a molar mass of ______g

IV. Molar mass of molecules a. To find the molar mass of molecules and compounds. i. Add the atomic masses of each atom in the compound 1. Ex.

• H20 • Hydrogen = 1.007 X ___ atoms = 2.014g • Oxygen = 15.999 X ___ atom = 15.999g 18.013g

V. Avogadro’s Number a. The number of particles in 1 mole of a substance. i. ______particles ii. 1 mole of carbon has 6.0221367 x 1023 1. ___ moles of carbon has ______VI. Converting between Units a. Moles  grams i. Multiply the number of moles times molar mass 1. MOLES x MOLAR MASS

MolarMass( g ) #Moles * 1Mole

b. grams Moles i. Divided the number moles by molar mass 1. MOLES ÷ Molar mass

1Mole #grams * MolarMass( g )

c. Moles  Particles i. Number of moles multiplied by 6.0221367 x 1023 1. Moles X Avogadros number

6.022X 10 23 #Moles * 1Mole

d. Particles  Moles i. Number of Particles divided by 6.0221367 x 1023 1. Particles ÷ Avogadros number

1mole #particles * 6.022x 1023