A Mole is Many Things

1. A Mole is Many Things

2. How do you measure matter? Measuring by mass…. • Potatoes are measured by the pound. • Gold is measured by the ounce. Measuring by volume…. • Apples are measured by the bushel. • Soda is measured by the liter. • Gasoline is measured by the gallon.

3. How do you measure matter? Some items are measured by counting howmany you have. • Eggs are measured by the dozen. • Pencils are measured by the gross.

4. The “chemical counting unit” is the mole. • The mole is the SI unit for amount of substance. • The particles of a substance could be atoms, molecules, or ions, which are very small.

5. Just as a dozen eggs represents 12 eggs, a mole (mol) represents 6.02 x 1023 representative particles of a substance. • This number is called Avogadro’s number, in honor of Amedeo Avogadro, and it is a very large number.

6. The Mole • Avogadro’s number is 6.02 x 1023. • A mole is 6.02 x 1023 particles of a substance.

7. How big is a mole? • 602000000000000000000000 particles, which is… • 602,000 x 1 million x 1 million x 1 million

8. If you had a mole of watermelon seeds, you would have a melon slightly larger than the moon.

9. A mole of donut holes would cover the earth and be 5 miles deep.

10. If you had a mole of pennies and stacked them up, the stack would 7 times the distance from the Earth to the moon.

11. A mole of rice grains would cover the land area of the Earth to a depth of about 75 meters. • A mole of rice grains is more grains than all the grain that has been grown since the beginning of time. • A mole of rice would occupy a cube about 120 miles on each edge.

12. Assuming that each human has 60 trillion body cells (6 x 1013) and the Earth’s population is over 6.7 billion (6.7 x 109), the total number of living human body cells on the Earth at the present time is 4.02 x 1023, or only 2/3 of a mole.

13. If one mole of pennies were divided up among the Earth’s population, each person would receive 9 x 1013 pennies. Personal spending at the rate of one million dollars a day would use up each person’s wealth in 2500 years. • Life would not be comfortable because the surface of the Earth would be covered in copper coins to a depth of at least 400 meters.

14. A representative particle is… • The smallest unit into which a substance can be broken down without a change in composition. • The representative particle of most elements is the atom.

15. Substance Representative particle • Element Atom • Diatomic element Molecule (Br2, I2, N2, Cl2, H2, O2, F2) • Molecular compound Molecule • Ionic compound Formula Unit

16. Remember: • A formula unit is the lowest whole number ratio of ions in an ionic compound.

17. Mole-Particle Conversion PracticeMole Samples

18. If a carbon atom has an atomic mass of 12.01 amu and a hydrogen atom has an atomic mass of 1.008 amu, we could say one carbon atom is about 12 times as massive as one hydrogen atom.

19. Would 100 carbon atoms be about 12 times as massive as 100 hydrogen atoms? • Would 1 mole of carbon atoms be about 12 times as massive as 1 mole of hydrogen atoms?

20. Scientists define the mole as the amount of substance that contains as many particles (atoms, molecules, of formula units) as there are atoms in exactly 12 grams of the carbon-12 isotope.

21. Molar Mass… is the mass of a mole of a substance. Gram atomic mass is the mass of a mole of atoms. Gram molecular mass is the mass of a mole of molecules. Gram formula mass is the mass of a mole of a substance.

22. Molar Mass • What is the gram atomic mass of zinc? • What is the gram molecular mass of CO2? • What is the gram formula mass of NaCl? • What is the molar mass of titanium?

23. Mole Fact References: • Professor Mole, Quality Science & Software, Inc. • Doris Kolb. “The Mole,” J. Chem. Educ. • Reactions and Reason, Heikkinan and Atkinson