WELCOME! Lab notebooks out! Sit wherever you’d like. (Wooden tables must be filled)

WARM-UP What were the 3 conversion factors you learned in the moles unit? How did you figure out each one? (very brief) A furry mole rat

UNIT 6: STOICHIOMETRY Derived from the Greek words:Greek στοιχείον  stoikheion = elementelement + μέτρον  metron = measuremeasure

WHY STOICHIOMETRY? You’ve learned how to convert between g, moles, molecules, and atoms of ONE element or compound (not that useful) How can we convert between two elements or compounds?  How much of each ingredient do I need to make a bottle of Vitamin Water, can of Axe Body Spray, tube of lip gloss?

THE HAMBURGER ANALOGY My recipe for a bacon double cheeseburger is: 1 hamburger bun 2 hamburger patties 3 slices of cheese 4 strips of bacon 1bun + 2patties + 3cheese + 4bacon 1 BD-cheeseburger

1BUN + 2PATTIES + 3CHEESE + 4BACON 1 BD-CHEESEBURGER If I have 5 bacon double cheeseburgers:  How many hamburger buns do I have?  How many hamburger patties do I have?  How many slices of cheese do I have?  How many strips of bacon do I have? Solve with dimensional analysis!!!!!!!

THE HAMBURGER ANALOGY 1bun + 2patties + 3cheese + 4bacon 1 BDcheeseburger If I have 1 bun, 2 patties, 3 slices of cheese and 4 strips of bacon, how many BDcheeseburgers can I make? If I have 1 dozen buns, 2 dozen patties, 3 dozen slices of cheese and 4 dozen strips of bacon, how many BDcheeseburgers can I make?

EQUATION = A CHEMISTRY RECIPE! CO (g) + 2H 2 (g)  CH 3 OH (g)  Recipe with Molecules:  1 molecule of CO plus 2 molecules of H 2 will produce 1 molecule of CH 3 OH  Recipe with Dozen of Molecules:  1 dozen molecules of CO plus 2 dozen molecules of H 2 will produce 1 dozen molecules of CH 3 OH  Recipe with Moles:  1 mole of CO plus 2 moles of H 2 will produce 1 mole of CH 3 OH

CO (G) + 2H 2 (G)  CH 3 OH (G) What do the coefficients in an equation tell you about the reactants and products? THE MOLE RATIO! Ratio of reactants used : products made 1: 2 :1 Can be used to make Predictions ! Forwards  or  Backwards.

WHAT DO THE COEFFICIENTS “MEASURE”? Can Represent Moles, Molecules, and Atoms, But not grams!!! But not grams!!! … because different atoms have different weights. … because different atoms have different weights.

CO (G) + 2H 2 (G)  CH 3 OH (G) 1. How many moles of CH 3 OH would be produced if you started with 4 moles of H 2 ? 4mol H 2 x 1 mol CH 3 OH = 2 mol CH3OH 2 mol H 2 2. Backwards: How many moles of CO would you need if you wanted to produce 5 moles of CH 3 OH? 3. Forwards: If you had 3.5 moles of H 2 how many moles of CO would you need to react with it?

UNKNOWN CARBONATE LAB You will discover the identity of the unknown carbonate (either X 2 CO 3 ) by using mole ratios!  What must be the charge on the unknown metal?  How do you know that? Let’s do the pre-lab! We will check answers in a few minutes! X 2 CO 3(aq) + 2 HCl (aq)  2 XCl (aq) + CO 2(g) + H 2 O (l)

UNKNOWN CARBONATE LAB Once you have at least 1 trial, go to two other groups and swap data so that you have a total of 2 trials. Wear goggles when dealing with HCl! You can pour the results down the sink when finished. X 2 CO 3(aq) + 2 HCl (aq)  2 XCl (aq) + CO 2(g) + H 2 O (l)

PROCESS OF CALCULATIONS (#3-8) Mass of CO 2 Moles of CO 2 Moles of X 2 CO 3 Molar Mass of X 2 CO 3 Mass of X Identity of X Identity of X Use Molar Mass! Use Mole Ratios! Use Proportions! Subtract out the CO3! Use Mass # on Per. Table!

UNKNOWN CARBONATE LAB WRAP-UP: X 2 CO 3(aq) + 2 HCl (aq)  2 XCl (aq) + CO 2(g) + H 2 O (l) 1. What does the charge of X have to be? 2. If the Mass of flask + X 2 CO 3 + HCl = g and Mass of flask and reacted solution = g, How many grams of CO 2 were released? 3. How many moles of X 2 CO 3 were reacted? 4. If you actually started with 2.02 g of X 2 CO 3, what is the mass of X & what element is it?

EXIT TASK Consider this equation for respiration: C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 0 If I have 3 mol of C 6 H 12 O 6, how many mol of CO 2 will I make? Homework: Finish Lab WoC read Pg. 282 #5-7, 9-12