1. 1. 294 g of sulfuric acid = ____ molecules 2. How many atoms of O? 1.8 * 10 24 molecules 7.2 * 10 24 atoms Day 5 10-14

3. A chemical reaction produces 98.0 mL of sulfur dioxide gas at STP. What was the mass (in grams) of the gas produced? 0.280 g SO 2

4. 896 dL of CO 2 gas contains how many atoms? 2.4e24 molecules 7.2e24 atoms

5. Converting: Mass to moles Moles to mass Moles to atoms / molecules / particles Atoms / molecules / particles to moles Moles to liters Liters to moles Changing a substance = = ______________ ___________ = _____________ = ________________

6. Percentage Composition Mass of element Mass of compound X (100) = % element in compound … tells how much an element contributes to the mass of the compound

7. Percentage Composition H 2 O??? 2 H: 2 * 1.0079 g = 2.0158 g 1 O: 1 * 15.999 g = 15.999 g 18.015 g (2.0158 g / 18.015 g) X 100 = 11.190% H (15.999 g / 18.015 g) X 100 = 88.810% O

8. Percentage Composition An unknown compound w/ a mass of 0.237 g is extracted from the roots of a plant. Decomposition of the sample produces 0.0948 g of C, 0.1264 g of O, and 0.0158 g of H. What is the % composition of the compound?

10. 1) 45 L of hydrogen gas = how many grams? Day 6 10-15 2) A sample of a compound contains 12.15 g of Mg and 19 g of F. What is the percent composition of this compound (SHOW WORK)?

11. Empirical formula – smallest whole- number mole ratio for a compound Empirical Formulas To Calculate: 1. Convert all elements involved to moles 2. Divide all elements by the smallest # of moles 3. Obtain smallest whole #ed ratio

12. A compound contains 13.5 g Ca, 10.8 g O, and 0.675 g H. What is the empirical formula? Empirical Formulas 1. Convert all eles. involved to moles 2. Divide all eles. by the smallest # of moles 3. Obtain smallest whole #ed ratio Ca = 0.337 moles O = 0.675 moles H =.675 moles Ca = 0.337 mols / 0.337 mols = 1 O = 0.675 mols / 0.337 mols = 2 H = 0.675 mols / 0.337 mols = 2 1 Ca : 2 O : 2 H CaO 2 H 2 Ca(OH) 2

13. Calculating Empirical Formulas In an unknown compound you find 4.04 g of N and 11.46 g O. Empirical formula?

14. Empirical formula – smallest whole- number mole ratio for a compound Empirical Formulas vs. Molecular Formulas Molecular formula – actual # of atoms of each ele. in a molecular compound Sometimes But not always! the same.

15. Molecular Formulas To Calculate: Compare the molar mass of the empirical formula to the molar mass of the molecular formula Molecular formula – actual # of atoms of each ele. in a molecular compound

16. Determine the molecular formula of the compound with an empirical formula of CH and a formula mass of 78.110 amu Empirical mass = 13.019 g/mol x = 6 Molecular formula = C 6 H 6 Determining Molecular Formulas

17. In an unknown compound you find 4.04 g of N and 11.46 g O. Empirical formula? This unknown compound has a molar mass of 108.0 g/mol. What is the molecular formula? Empirical formula = N 2 O 5 Empirical mass = 108.009 g/mol Molecular formula = N 2 O 5

19. What result do you expect from a match test if …. hydrogen is present? carbon dioxide is present? Day 1 10-16

20. 67.2 L of CH 4 gas = ___ grams 44.8 mg of solid Carbon = ___ L

21. Prelab # 5: According to the reaction in # 1, for every ___ pieces of cupric chloride ___ pieces of copper are produced. As a result we should expect to produce ___ of a mole of cpper in the first reaction, which would be ___ grams of Cu. SHOW YOUR WORK!

22. A sample of a compound contains 3.003 g of C, 0.504 g of H, and 4.000 g of O. If the molar mass is 180.157 g/mol what is the molecular formula. Empirical formula Molecular Formula Question of the Day Day 2 10-17

23. A sample of a compound contains 6.0 g of C and 16 g of O. The total sample is 22 g. The molecular molar mass is 44 grams Percentage Composition Empirical formula Molecular formula Determining Molecular Formulas Day 3 10-18

25. 56,000 mL of O 2 gas = how many molecules of O 2 ? How many atoms of O?

26. - 2 molar mass convs. - 2 Av.’s # convs. - 2 Av.’s law convs. - 2 multi-step convs. - 1 percentage comp. - 1 empirical formula - 1 molecular formula - 2 content ?s (no math) 13 questions

27. Review section 10.3 (if needed) and complete #s 45-49 for # 49 the %s can be treated as grams and used to find moles… Assignment due Tuesday 10-11

28. Book #s 45-49 = NOW Create-a-Test = momentarily Presentations = Wednesday 10-12 Chapter Quiz = Wednesday 10-12

29. Calculate the mass of Cu produced? Mass of beaker and Cu – mass of beaker

30. Calculating percent yield Percent yield – a way to compare how much you “should” get to how much you actually got Percent Yield = Actual yield Theoretic yield X 100

31. Desk clear and mentally prepare for Quest. Quest Group Quest Presentations

32. Day 6 10-5 0.112 kL of CO gas contains how many grams? How many atoms? 140 grams CO 6e24 atoms

33. Review (if needed) pages 325-327 AND complete #s 33, 34, 35, and 36 on pages 326 and 327. Day 5 10-4

34. Homework # 2 = now Postlabs = Friday 10-7 (tomorrow) Presentations = Wednesday 10-12 Chapter Quiz = Wednesday 10-12 Day 1 10-6

35. 1. A mole is a _________, plus it relates to ______. 2. Molar mass of Be(NO 3 ) 2 3. 3.0 grams of Be(NO 3 ) 2 = ___ moles 4. = ___ molecules?