Moles Part 1 – Particles

Aim CE3:How many different measures is a mole?

Intro to the Mole, the Chemist’s Dozen

•A mole - a given number of particleso A pair of shoes = 2 itemso A dozen roses = 12 itemso A mole of water = 6.02 x 1023 items or

particles

A mole measures the number of particles in different samples

•1 mole of iron (Fe) has 6.02 x 1023 atoms

•2 moles of iron has how many atoms? 2 x (6.02 x 1023) = 1.204 x 1024 atoms

•1 mole of sulfur (S) has 6.02 x 1023 atoms

•How many moles of sulfur are in 8 moles?2 x (6.02 x 1023) = 1.204 x 1024 atoms

•1 mole of water has 6.02 x 1023 molecules

•5 moles of water has how many molecules?5 x (6.02 x 1023) = 3.01 x 1024 molecules

•1 mole of water has 6.02 x 1023 molecules

•How many ATOMS are in 1 mole of water?

•This can be answered using proportions

•H2O = 3 atoms for each molecule

3 atoms = X moles atoms1 molecule 1 mole molecules X = 3 moles atoms

•How many atoms are in 3 moles of atoms? 3 moles atoms = X atoms 1 mole molecules 6.02 x 1023 moleculesX = 3x(6.02 x 1023) =18.06 x 1023 atoms

•Knowing that all moles have the same number of particles is important in chemical reactions

•It allows the chemist to determine how many particles will be reacting

•Example:2 H2 + O2 2 H2O

o The equation tells us that 2 molecules of H2 will react with 1 molecule of O2 to make 2 molecules of water

o It ALSO tells us 2 moles H2 and 1 mole O2 will produce 2 moles of water

o Remember, 1 mole = 6.02 x 1023 particles!o That’s a lot of molecules in this reaction!

Practice 1. How many atoms are in a 2.00 mole

sample of aluminum?

2. How many molecules are in a 0.500 mole sample of ammonia?

3. How many atoms are in a 1.00 mole sample of the compound hydrogen bromide (HBr)?

4. How many ions are in a 4.00 mole sample of sodium chloride (NaCl)?