1. Yes, more math!!

2. Plan of the Day Review Balancing equations Mass to mass problems Introduce Mass to Volume Equations Introduce Volume to Volume Equations HW Time

3. Plan of the Day 4/15/11 Review Molar Volume Lab Recalculations Review Ch 10 Test In groups, work through each problem Take notes as needed Questions??? Ch 10 Retest next class – best score Current HW Questions???

4. Plan of the Day 4/18/11 Review Molar Volume Lab Recalculations Review Ch 10 Test In groups, work through each problem Take notes as needed Questions??? Ch 10 Retest next class – best score Current HW Questions???

5. Plan of the Day 4/20/11 Ch 10 Retest Today – for best score Any last minute Questions? Continue w/ Ch 11 & 12 HW Mass/Volume Lab 4/22/11 Mass/Volume Lab 4/22/11 Chapter 11 & 12 Test 4/26/11 Chapter 11 & 12 Test 4/26/11

6. Plan of the Day 4/21/11 Mass/Volume Lab Conduct, calculate & turn in Continue w/ Ch 11 & 12 HW Chapter 11 & 12 Test 4/25/11 & HW Quiz

7. Plan of the Day 4/22/11 Mass/Volume Lab Conduct, calculate & turn in Continue w/ Ch 11 & 12 HW Ch 11 #1-11 & 15 Ch 12 #1-10 Chapter 11 & 12 Test 4/26/11 & HW Quiz

8. Balancing Equations What do you remember? (lets just brainstorm!) What do the balanced equations tell you? Why? Law of Conservation—who can explain? How do Chemists use this relationship? Like a recipe! Let’s try one: Ca + H 2 O  Ca(OH) 2 + H 2 Ca + 2 H 2 O  Ca(OH) 2 + H 2 And another : C 2 H 6 + O 2  CO 2 + H 2 O 2C 2 H 6 + 7O 2  4 CO 2 + 6 H 2 O

9. Balancing Equations Video’s? http://www.youtube.com/watch?v=RnGu3xO2h74&play next_from=TL&videos=h7PQ10ClYzI http://www.youtube.com/watch?v=RnGu3xO2h74&play next_from=TL&videos=h7PQ10ClYzI

10. Mass to Mass Example 1 Given a certain amount of a reactant how do we find the mass of a certain product? 2C 2 H 6 + 7O 2  4CO 2 + 6 H 2 O How much ethane would it take to get 20 grams of carbon dioxide? 1. Balance Equation 2. Identify known & unknown 3. Equation to solve a.Mass of known to moles of known b.Moles known to moles unknown c.Moles unknown to mass unknown Balance Equation

11. Using molecular mass g/mol Mass Using the ratio in a balanced equation allows us to convert from one substance to another. Moles Using molecular mass g/mol Mass

13. Mass to Mass Example 2 How many grams of glucose form when 88.0 g of CO 2 reacts? CO 2 + H 2 0  C 6 H 12 O 6 + 6 O 2 First what are the steps? Using words write them down. Now what purpose does each step serve? Using words! Share with the class! Calculate Answer is 60.0g C 6 H 12 O 6

14. Mass to Volume… Blue Book Ch. 11 What is the relationship between moles and volume with gases? How do we get from volume to mass and vice versa? What are the steps?

15. Mass to Volume cont.. 1. Balance Equation 2. Identify known & unknown 3. Mass to Moles (known) 4. Moles (known) to Moles (unknown) 5. Moles (unknown) to Volume of unknown (22.4 dm 3 = 1 mole) MolesVolumeMolesMass

16. Ch 11 Mass to Volume Example 1 Calculate the volume of oxygen produced at STP by the decomposition of 10.0 g of potassium chlorate, KClO 3. KClO 3  KCl + O 2 Hint Balance the equation I.D. known & unknown Convert the grams to moles Convert moles of KClO 3 to moles of O 2 Convert moles of oxygen to volume using our handy 22.4 dm 3 = 1 mol of any gas @STP! Answer: 2.74 dm 3 O 2

17. Ch 11 Mass to Volume Example 2 How many cubic centimeters of hydrogen are produced by the reaction of.750 grams of sodium metal with excess water? Na + H 2 O  NaOH + H 2 Hint Balance the equation Convert the sodium to moles Convert moles of sodium to moles of hydrogen Convert moles of hydrogen to volume using our handy 22.4 L = 1 mol of any gas! Throw in a cm to dm conversion Answer: 365 cm 3

18. Ch 11 Mass to Volume Example 3 Al reacts with HCl to produce aluminum chloride and hydrogen gas. How many dm 3 of hydrogen at STP are produced if Al reacts with an HCl solution which has a mass of 80.0g and contains 70.0% water? Al + HCl  AlCl 3 + H 2 If 80.0 g of a solution of HCl is 70% water then it is 30% pure HCl, use part to whole: 30g pure HCl/100 g solution of HCL ANSWER: 7.36dm 3 H 2

19. Ch 11 Mass to Volume Example 4 How many grams of ammonium sulfate must react with excess sodium hydroxide to produce 400 cm 3 of ammonia measured at 27 o C and 98.0 kPa? (NH 4 ) 2 SO 4 + NaOH  Na 2 SO 4 + NH 3 + H 2 O Answer: 1.04 g (NH 4 ) 2 SO 4

20. Ch. 12 Volume to Volume: Ch. 12 Volume to Volume: How do chemists convert volume to volume??? First Step? Balance the Equation Second Step? ID known & unknown Third Step Volume of known to Moles of known Fourth Step? Moles of known to moles of unknown Next? Moles of unknown to volume of unknown. Balance the Eqn Volume Moles (Ratio) Volume

21. Volume to Volume Example 4 If 6.00 dm 3 of oxygen are available to burn carbon disulfide, how many dm 3 (liters) of carbon dioxide are produced? The products of the combustion of carbon disulfide are carbon dioxide and sulfur dioxide. CS 2 + O 2  CO 2 + SO 2 1. Volume to Mole (known) 2. Mole (known) to Mole (unknown) 3. Mole (unknown) to Volume (unknown) 2.0 dm 3 CO 2

22. Anybody see a shortcut?? All gases So… 6.00dm 3 1 dm 3 CO2 3dm 3 O2 = 2.oo dm 3 CO 2 the known volume can be multiplied by the mole ratio to find unknown volume (see p. 120 in Blue Book) CAREFUL … only if the gases are measured under the same conditions of temperature & pressure

23. Chapter 12 – example 3 When a hydrocarbon such as ethylene burns complete in oxygen, the products are carbon dioxide and water. Calculate the liters of air required to burn completely 15.0 dm 3 of ethylene gas, C 2 H 4, measured at STP. Assume that air contains 21.0% oxygen by volume. C 2 H 4 + O 2  CO 2 + H 2 O *Hint: the answer needs to be stated in dm 3 of air – but only oxygen in the air reacts with ethylene gas. Answer: 214 dm 3 of air

24. Ch 12 Volume to Volume Example 5 How many liters (dm 3 ) of air measured at 98.5 kPa and 100 o C are required to produce 200dm 3 of CO2 measured at the same pressure and 20 o C? Assume that air contains 21% oxygen by volume and that the CO2 is being produced from CO. CO + O 2  CO 2 1. Balance Equation 2. Old/New Chart to find missing volume 3. Conversions? 1 dm 3 O 2 = 2 dm 3 CO 2 21 dm 3 O 2 = 100 dm 3 air 4. Put it all together ANSWER: 606 dm 3 air

25. Chapter 11 Mass-Volume HW #1-11 & 15 Chapter 12 Volume-Volume HW #1-10 *Chapter 11 & 12 Test: 4/19 & 4/20* (B-day) (A-day) (B-day) (A-day)