1. Chapter 8 Molecular & Formula Masses

2. How many minutes does it take light to reach us from the sun which is 93,000,000 miles distant.

3. The following information will be useful: –speed of light = 3.0 x 10 8 m/s –1km = 0.6214 mi

4. How many minutes does it take light to reach us from the sun which is 93,000,000 miles distant. 93,000,000 mi

5. How many minutes does it take light to reach us from the sun which is 93,000,000 miles distant. 93,000,000 mi 0.6214 mi km 1000 m 3.0 x 10 8 m s 60 s min = 8.3 min

6. Atomic mass The atomic mass is the average mass of an atom.

7. When using atomic masses make sure to round to at least one decimal place.

8. What is the atomic mass of actinium (Ac)? 227.0278 227.0

9. What is the atomic mass of hydrogen (H)? 1.00794 1.0

10. What is the mass of hydrogen (H 2 )? 2.0

11. Vitamin A: C 20 H 30 O The first of the 13 vitamins to be discovered, it plays a vital role in the growth and repair of body tissues, and is particularly important in maintaining good eyesight and healthy skin, as well as aiding in bone and teeth formation. Vitamin A-rich foods include: Liver, sweet potatoes, carrots, mangoes, spinach, cantaloupe, dried apricots, milk, egg yolks, mozzarella cheese.

12. Determine the Molecular Mass of Vitamin A C 20 H 30 O

13. Determine the Molecular Mass of Vitamin A C 20 H 30 O 20 x 12.0 = 240.0 30 x 1.0 = 30.0 1 x 16.0 = 16.0 = 286.0 amu

14. H H 2 ONaCl H is an atom and it would therefore have an atomic mass. H 2 O is a molecule and it would therefore have a molecular mass. NaCl is neither an atom or a molecule and would therefore have a formula mass.

15. Formula Mass The formula mass is the mass of an ionic compound. An ionic compound is formed from a combination of metals and nonmetals. Formula masses are calculated the same as molecular masses.

16. Determine the Formula Mass of Calcium Phosphate Ca 3 (PO 4 ) 2 3 x 40.1 = 120.3 2 x 31.0 = 62.0 8 x 16.0 = 128.0 = 310.3 amu

17. The Mole

18. A counting unit similar to a dozen, except instead of 12, it’s 602 billion trillion 602,000,000,000,000,000,000,000 6.02 X 10 23 (in scientific notation) Amedeo Avogadro (1776 – 1856)This number is named in honor of Amedeo Avogadro (1776 – 1856), and is called Avogadro’s Number.

19. The Mole (mol) 1 mole of cookies = 6.02 x 10 23 cookies 1 mole of cars = 6.02 x 10 23 cars 1 mole of Al = 6.02 x 10 23 ? 1 mole of Al = 6.02 x 10 23 Al atoms 1 mole of water = ? 1 mole of H 2 O = 6.02 x 10 23 H 2 O molecules

20. How big is a mole? How many cents are in one mole of pennies?

21. How big is a mole? How many cents are in one mole of pennies? 6.02 x 10 23 ¢

22. How big is a mole? How many dollars are in 6.02 x 10 23 ¢?

23. How big is a mole? How many dollars are in 6.02 x 10 23 ¢? = $6.02 x 10 21 6.02 x 10 23 ¢ 100¢ $1

24. How big is a mole? There are about 7.0 billion (7.0 x 10 9 ) people on earth. If we divided the 1 mole of pennies ($6.02 x 10 21 ) equally among all the people on earth how many dollars would you have?

25. How big is a mole? There are about 7.0 billion (7.0 x 10 9 ) people on earth. If we divided the 1 mole of pennies ($6.02 x 10 21 ) equally among all the people on earth how many dollars would you have? $6.02 x 10 21 7.0 x 10 9 people = $8.6 x 10 11 /person $860,000,000,000 = 860 billion dollars

26. How big is a mole? How many years would it take you to spend your 860 billion dollars ($8.6 x 10 11 ) if you spent $94,000 per day?

27. How big is a mole? How many years would it take you to spend your 910 billion dollars if you spent $100,000 per day? $8.6 x 10 11 $94,000 day 365 days year = 25,000 years

28. Neanderthals died out about 25,000 years ago

29. If you had one wish, what would it be?

30. Would you wish to be a “millionaire”?

31. “Mollionaire”

32. Homework Molecular and Formula Mass Worksheet. Don’t forget to show your work on your calculations.