1. Volume – Gas is $4.00 a gallon Mass – Apples are $1.49 a pound Count – Bananas are $0.79 each How do we measure?

2. Certain words represent a number Dozen = ? Couple = ? Score = ? Mole = ?

3. What is a Mole?

4. A number of particles 1 mole = 6.02x10 23 This is Avagadro’s Number

5. Conversion Problems… Dozen = 12 so…… 1 Dozen = 12 = 1 121 Dozen 1 mole = 6.02x10 23 so….. 1mole=6.02x10 23 particles = 1 6.02x10 23 particles 1 mole

6. Problems ①How many eggs are in 5.5 dozen? ②How many years is “four-score and seven years”? (Do you know who said this?)

7. Problems ①How many moles are in 3.80 x 10 24 atoms of Ca? ②How many molecules are in 0.280 mole of H 2 O?

8. Skittles How may schools could 1 mole of skittles fill? 1 liter = 1340 skittles 1 box = 28.4 liters 1 room = 14,000 boxes 1 school = 500 rooms

9. The Mass of a Mole of an Element Molar Mass: The mass of a mole of an element – Look at the Periodic Table 1 mole Carbon = 12.01g

10. What is the molar mass of…. ①Oxygen = ②Sulfur = ③Iron = ④Sodium =

11. The Mass of a Mole of a Compound Molar mass of a compound: 1)Find the number of grams of each element in the compound 2)Add the masses of all the elements in the compound

12. What is the molar mass of…. ①H 2 O =? ②SO 3 = ? ③NaCl = ?

13. Counting by measuring mass lab Paper Clips - Pg 286 Each group turns in 1 paper with your data and questions 1-3.

14. Mole – Mass Relationship Convert between the mass of a substance and the moles of a substance using the molar mass mass (grams) = # of moles x mass (grams) 1 mole moles = mass (grams) x 1 mole mass (grams)

15. Mass & Moles Problems ① What is the mass of 3 mol of NaCl? mass NaCl = ______ x _______ = ______ ②How many moles of (Fe 2 O 3 ) are in a 92.2 g sample? mol (Fe 2 O 3 ) = ________ x ________ = _______

16. Percent Composition of a Compound Percent Composition: Percent (by mass) of each element in a compound % mass of element = mass of element x 100% mass of compound

17. What is the percent composition of… ①A 13.60g sample containing only Mg and O is decomposed and 5.4g O 2 is obtained. What is the percent composition of the original compound?

18. Percent Composition If you don’t know the mass of the compound, use the molar mass: % mass = mass of element in 1 mol compound x 100% molar mass of compound ①What is the percent composition of H 2 O?

19. Percent Composition ①Calculate the amount of carbon in 2.56g Na 2 CO 2

20. Popcorn Lab 1.How many grams of water are in a kernel (average)? 2.What is the percent composition of water in an kernel? 3.How many moles of water (on average) are in a kernel? 4.How many moles of oxygen? 5.How many moles of hydrogen? 6.How many atoms of oxygen? 7.How many atoms of hydrogen? 8.How many grams of oxygen? 9.How many grams of hydrogen? 10.What is the percent composition of water (what percent by mass is H, O?)

21. Mole – Volume Relationship Avogadro’s hypothesis: equal volumes of gases at the same temperature and pressure contain equal numbers of particles – Standard Temperature and Pressure (STP): Temperature = 0°C Pressure = 1 atmosphere (atm) or 101.3 kPa – Molar Volume = 22.4L

22. Mole – Volume Relationship

23. Mass – Volume Relationship Volume of gas = moles of gas x 22.4 L 1 mole ①What is the volume of 0.6 mol SO 2 at STP? ②How many moles of O 2 gas are in 0.4L at STP?

24. Moles!

25. Molarity Calculating Concentrations Molarity = Number of mol of solute Number of L of solution Solute = The Dissolved Substance Ex: Sugar, Salt Solvent: The Dissolving Medium Ex: Water

26. Calculating Concentrations A saline solution contains 0.90g NaCl in exactly 100mL of solution. What is the molarity of the solution?

27. Calculating Concentrations 1.How many moles of solute are present in 1.5L of 0.70M NaClO? (bleach) If you were to add solvent to the solution, what would happen to the molarity?

28. Parts Per Million (ppm) Calculating Concentrations One part per million parts 1ppm = 1mg of solute 1 L of solution Because 1mL of water = 1mg So 1L of water would be 1,000,000mg.

29. Empirical Formulas The lowest whole-number ratio of elements in a compound Ex: empirical formula C 2 H 2 CH C 4 H 4 CH C 8 H 8 CH

30. What is the empirical formula… ①A compound is 25.9% nitrogen and 74.1% oxygen. What is the empirical formula? (Hint: Remember, percent composition is MASS) 1.Assume the compound is 100g. 2.Change ratio of masses to moles. 3. Reduce ratio to lowest whole-number ratio by dividing by molar quantity with smaller number of moles. 4.If ratios are still not a whole number, multiply each part of the ratio that will convert both to whole numbers

31. What is the empirical formula of… ①A compound that is 94.1% oxygen and 5.9% hydrogen.

32. Molecular Formulas Either: -the same as the empirical formula -a simple whole-number multiple of the empirical formula. Empirical FormulaMolecular Formula CH 2 OCH 2 O CH 2 Ox 2C 2 H 4 O 2 CH 2 Ox 6C 6 H 12 O 6

33. ①Calculate the molecular formula of a compound whose molar mass is 60.0g/mol and empirical formula is CH 4 N. 1.Calculate the mass of the empirical formula. 2.Divide the molar mass by the mass of the empirical formula to find a whole number 3.Multiply the subscripts by the whole number found

34. ①Find the molecular formula of ethylene glycol (used in antifreeze). The molar mass is 62g/mol and the empirical formula is CH 3 O.