 # The MOLE Mole The mole is a word

• Slides: 10 The MOLE ? Mole The mole is a word that means a very specific number. We know about the word “dozen” it means 12. The mole means 6. 0221367 x 1023, we just round it to 6. 02 x 1023. If we have a mole of anything we have 6. 02 x 1023 of them. That’s a lot of anything to have, unless you think about atoms and molecules. 1 mole = 602, 213, 670, 000, 000 particles Avogadro’s number Avogadro's number and is denoted by NA. It is derived from exactly 12 grams of carbon-12. 12 grams of carbon -12 has approximately 6. 02 x 1023. Amadeo Avogadro (1776 -1856) What do we do with it? It happens to be the SI unit of amount of anything. We use it in chemistry when working with chemical equations. It can stand for: atoms, molecules, or formula units. The mass of a mole of any one element is equal to its atomic mass. So… 1 mole “C” = 6. 02 x 1023 “C” atoms = 12. 01 grams 1 mole C 6. 02 x 1023 atoms 12. 01 g All of these can be filled around to make 3 more conversion factors, for a total of 6. What is the mass of 2. 5 moles of aluminum? We look on the Periodic table to find the atomic mass of Al. This tells us that 1 mole of Al = 26. 98 grams. Time for math: 2. 5 moles Al x 26. 98 g = 67. 45 g of Al 1 mole of Al The Key For an example lets use gold (Au). 1 mole of Au = 6. 02 x 1023 atoms of Au = 196. 97 grams of Au These three numbers are all we need to solve any molar equations dealing with gold. Examples: 1. What is the mass of 4. 5 moles of Au? 2. How many atoms of Au will have a mass of 89. 60 g? 3. How many moles of gold do you have if you have 5. 24 x 1026 atoms of gold? 4. What will be the mass of 5. 24 x 1026 atoms of Gold? What is the mass of 4. 5 moles of Au? 1 mole of Au = 6. 02 x 1023 atoms of Au = 196. 97 grams of Au 4. 5 mol Au x 196. 97 g = 886. 36 g Au 1 mol Au How many atoms of Au will have a mass of 89. 60 g? 1 mole of Au = 6. 02 x 1023 atoms of Au = 196. 97 grams of Au 89. 60 g Au X 6. 02 x 1023 Au atoms = 3. 06 x 1021 atoms Au 196. 97 Au You are going to need one of these!