1. Agenda: Feb 25 th Monday Turn in Entry task sheets (If you were gone Friday) Pick up/Fill out/Turn in “I can” Sign up for a clicker

2. I Can… Describe how a mole is used in chemistry Relate a mole to common counting units. Calculate the number of moles  in a given mass Calculate the number of moles  particles. Calculate the molar mass of a compound. Calculate particles  moles  grams Explain what is meant by the percent composition of a compound. Determine the empirical and molecular formula for a compound from mass percent and actual mass data.

3. Break out: Scratch paper Calculator

4. How many atoms are there in 0.365 moles of calcium? 1.2.1973 x 10 23 2.2.20 x 10 23 3.6.06 x 10 -25 4.6.063 x 10 -25 Response Grid

5. How many moles are there in 1.265 x 10 34 formula units of potassium chloride? 1.7.62 x 10 -57 2.7.615 x 10 57 3.2.10 x 10 -10 4.2.101x 10 10 Response Grid

6. What is the mass of 4.7x10 22 formula units of lead II iodide? 1.26 2.6.1 x 10 43 3.36 4.25.5 Response Grid

7. Calculate the number of molecules in 34.5 grams of dicarbon heptahydride? 1.1.78 x 10 -21 2.6.70 x 10 23 3.1.8 x 10 -21 4. 6.70x 10 -23 Response Grid

8. Calculate the mass of 0.67 moles of iron III hydroxide? 1.72 grams 2.6.3 x 10 3 grams 3.50 grams 4. 71.6 grams Response Grid

9. How many moles are in 236 grams of tin IV oxide? 1.7.10 x10 4 moles 2.0.787 moles 3.1.56 moles 4. 1.567 moles Response Grid

10. What is the percent of carbon in barium carbonate? 1.3.0 % 2.6.1% 3.14% 4. 20% Response Grid

11. What if a substance contains 81.82% carbon and 18.18% hydrogen, what is the empirical formula? 1.C 2 H 2 2.C 3 H 3. C 3 H 8 4.C 2 H 5 Response Grid

12. A compound was found to contain 49.98g carbon and 10.47g hydrogen. The molar mass is found to be 58.12 g/mol. Determine the molecular formula. 1.C 2 H 5 2.C 4 H 10 3. C 5 H 10 4.C 2 H 5 Response Grid

13. 2.50 grams of copper II sulfate was heated to yield 1.59 grams of anhydrous copper II sulfate. Calculate the hydrate formula for copper II sulfate. 1.Copper II sulfate dihydrate 2.Copper II sulfate tetrahydride 3.Copper II sulfate pentahydrate 4.Copper II sulfate hexahydride Response Grid

14. If 2.28 grams of hydrated magnesium sulfate is placed in a 14.26 gram evaporation dish and heated. The cooled evaporation dish is weighed to be 15.46 grams, how much water was driven off and anhydrous magnesium sulfate remains- respectively. 1.1.2g and 1.08 g 2.1.08 g and 1.2 g 3.13.18 g and 1.08 g 4.15.46 g and 16.54g Response Grid

15. Look at Lab Data tables Definitions of terms (see notes) LABEL your set-ups (90% the battle) HAVE A CALCULATOR!! No cell phones PERIOD!!

16. STUDY YOUR NOTES!! Bring any late assignments in for ½ credit Go online for last minute cramming! I’m NOT available for “cramming”