The M & M Lab: What if we had 6.02 x M&M’s and we spread them out over the whole state of Washington, how deep would it be? Yum

The Mole 1 dozen = 1 gross = 1 ream = 1 mole = x That is a REALLY BIG number…

Suppose we invented a new collection unit called a Wik. One Wik contains 8 objects. 1. How many paper clips in 1 Wik? a) 1b) 4c) 8 2. How many oranges in 2.0 Wik? a) 4b) 8c) gummy bears is how many Wiks? a) 5b) 10c) 20 Learning Check

Just How Big is a Mole? Enough soft drink cans to cover the surface of the earth to a depth of over 200 miles. If you had Avogadro's number of unpopped popcorn kernels, and spread them across the United States of America, the country would be covered in popcorn to a depth of over 9 miles. If we were able to count atoms at the rate of 10 million per second, it would take about 2 billion years to count the atoms in one mole.

A mole = Avogadro’s Number 6.02 x Otherwise known as“Avogadro’s Number” in honor of the Italian chemist Amadeo Avogadro ( ). Amadeo Avogadro

The Mole 1 dozen cookies = 12 cookies 1 mole of cookies = 6.02 X cookies 1 dozen cars = 12 cars 1 mole of cars = 6.02 X cars 1 dozen Al atoms = 12 Al atoms 1 mole of Al atoms = 6.02 X Al atoms Note that the NUMBER is always the same, but the MASS is very different! Mole is abbreviated mol

= 6.02 x C atoms = 6.02 x H 2 O molecules = 6.02 x NaCl “molecules” A Mole of Particles A Mole of Particles Contains 6.02 x particles 1 mole C atoms 1 mole H 2 O molecules 1 mole NaCl molecules

6.02 x particles 1 mole particles or 1 mole particles 6.02 x particles Note that a particle could be anything! Avogadro’s Number as Conversion Factor

The Mole So how do we use the mole in Chemistry? There are 6.94 grams of lithium in one mole of Li atoms. If we have one mole of Carbon how many grams do we have? Notice, these are called atomic weights on your periodic charts

Using the Mole We use the mole to convert a measured mass of an element to find the # of atoms that are present. Ex: Mass 12g of carbon-12 and you know you’ll have 1 mole of carbon which is 6.02 x atoms of carbon. (cool, eh?)

Calculations with Moles: Converting moles to grams How many grams of lithium are in 3.50 moles of lithium? 3.50 mol Li = g Li 1 mol Li 6.94 g Li 24.3 There are 24.3 grams of lithium in 3.50 moles of lithium.

Calculations with Moles: Converting grams to moles How many moles of lithium are in 18.2 grams of lithium? 18.2 g Li = mol Li 6.94 g Li 1 mol Li 2.62 There are 2.62 moles of lithium in 18.2 grams of lithium.

Calculations with Moles: Using Avogadro’s Number How many atoms of lithium are in 3.50 moles of lithium? 3.50 mol Li = atoms Li 1 mol Li 6.02 x atoms Li 2.11 x There are 2.11 x atoms of lithium in 3.50 moles of lithium.

Calculations with Moles: Using Avogadro’s Number How many atoms of lithium are in 18.2 g of lithium? 18.2 g Li = atoms Li 1 mol Li6.02 x atoms Li 1.58 x g Li1 mol Li