UNIT 5: THE MOLE AND AVOGADRO’S NUMBER Chemical Quantities

Measurement of Matter  How do you measure matter?  How would you find the number of M&Ms?  Three ways to measure matter…  Count  Volume  Mass

Measurement of Matter  To measure matter in chemistry we use the mole???  Mole reading

Measurement of Matter  A mole of any substance contains Avogadro’s number of representative particles or 6.02 x units.  6.02 x = Avogadro’s Number = 1 mole  Units can be atoms, molecules, or anything else really.

Measurement of Matter  Converting Number of Particles to Moles  T-tables Yeah!  Converting Moles to Number of Particles ____ moles6.02 x units =??? units 1 mole

Measurement of Matter  Practice  Steps: 1. Identify what you need to convert to. 2. Use the numerical value given to start your t-table 3. Use the conversion 1mole = 6.02 x units making sure the units cancel (top to bottom). 4. Put your answer in scientific notation if needed (over 1,000 or smaller than 0.000…), round to two decimals or three numbers, and include your units!

Measurement of Matter  Practice  How many moles of magnesium is 1.25 x atoms of magnesium?  Answer:  mol 1.25 x atoms1 mole 6.02 x (atoms)

The Mole: Measurement of Matter  Practice  How many atoms are in 2.12 mole of propane (C 2 H 6 )  Hint it’s a compound so how many atoms do you have?  Answer:  1.02 x atoms 2.12 moles C 3 H x molecules C 3 H 8 8 atoms 1 mole C 3 H 8 Molecule C 3 H 8