Chapter 9 Reviewer 404k5p

9A. 1. 2. 3. 4. 5. 6. 7. 8.

What is Avogadro’s number, and what is its physical significance? How many atoms are found in 600.g of iron? Give one benefit and one disadvantage of using structural formulas. What is the difference between an empirical formula and molecular formula? Give the structured, molecular, and empirical formulas of hydrogen peroxide. How many moles of atoms are in 1.00 lb (454 g) of lead? Find the molar mass of vitamin A (C20H30O). DDT, an insecticide banned in the United States, has the formula C14 H9 Cl5. Find its percent composition. 9. Find the molecular formula for acetone (molar mass 58.0g/mol), used to make nail polish and other industrial products. Its composition is 62.0%carbon, 10.4% hydrogen, and 27.6% oxygen.

9B 

1. The reaction that occurs when iron rusts is shown below.4 4Fe (s) + 3O2 (g)  2Fe2O3 (s) a. b. c. d.

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How many moles of rust can be produced from3.2 moles of iron metal? How many moles of oxygen will be consumed in this process? What mall of iron metal is needed to form 100.0 g of rust? How many molecules of oxygen will be needed to react with 50.0 g iron metal?

2. In regard to the reaction introduced in Question 1: a. If 200.0G of Fe react fully with O2, what is the theoretical yield of Fe2O3? b. If the actual yield is 252.7 g, what is the percent yield?

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DS 3. If about 47 thousand metric tons of sulfuric acid is industrially produced every year in the United States, how many moles are produced? (I T =1000 kg) DS 4. Write the net reaction for the production of sulfuric acid. DS 5. About 60% of the sulfuric acid produced worldwide is used to produce phosphoric acid of fertilizers. That reaction is : Ca2F(PO4)3 + 5H2SO4 + 10H2O  5CaSO4 X 2H2O + HF + 3H3PO4 If about 16,000 metric tons of phosphoric acid is produced every year in the united states, how many metric tons of sulfuric acid are required?

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DS 6. Can you think of a way to reduce emissions from the contract process or to lower the cost of sulfuric acid production? DS 7. Since sulfuric acid is toxic and polluting, should Christians oppose its creation and use? Why or why not? In answering this question, consider the benefits of the products in which it is used. Consider also the benefits of not using the chemicals.

1.Describe the relationship between Avogadro’s number and a mole of a substance. 2. When determining a compound’s empirical formula, if your calculated mole amounts are not equal to whole numbers, what must you do? 3. What term describes the calculations used to relate the amounts of reactants and products in a chemical reactions? 4. Explain why excess reactants often remain in a chemical reaction. 5. Give at least two reasons why the actual yield of a chemical reaction is typically less than the calculated theoretical yield. 6. The molar mass of an element is obtained by taking its atomic mass from the periodic table and changing the unit from atomic mass units to grams per liter. 7. A compound’s empirical formula is in some cases the same as its molecular formula. 8. The coefficients in a balanced chemical equation show the mole ratio of the substances in the reaction. 9. Give the molar mass for H, Sc, As, I, and U. Give your answers with four significant digits and correct units. 10. How many atoms are in the following? a. 12.01 g of C b. 16.00 g of O c. 1.008 g of H 11. How many moles a. of Fe are in 37.0 g of Fe? b. of Kr are in 4.58 x 1020 Kr atoms? c. of NaIO3 are in 3.25 x 1026 formula units of NaIO3? 12. Calculate the molar mass of the following compounds: a. N2O3 b. Mg3N2 c. AgNO3

13. How many a. Fe atoms are in 0.256 mol of Fe? b. Kr atoms are in 3.87 g of Kr? c. AlCl3 formula units are in 6.17 mol of AlCl3? d. NaIO3 formula units are in 8.58 g of NaIO3? 14. What is the mass in grams of a. 6.58 mol Fe? b. 8.58 x 1028 atoms Kr? c. 1.05 mol AlCl3? d. 3.17 x 1018 formula units NaIO3? 15.

16. What mass of vitamin E contains 0.500 g of C, given that vitamin E is 80.8% C by mass?

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19. Aspirin is the common name for acetyl salicylic acid. If 100 g of aspirin contains 60.00 g C, 4.480 g H, and 35.53 g O, what is its empirical formula? 20. Lidocaine is a widely used local anesthetic. A laboratory analysis of lidocaine reveals that a 5.000 g sample of lidocaine contains 3.588 g C, 0.473 g H, 0.598g N, and 0.342 g O. A) What is the percent composition of lidocaine? B) What is the empirical formula of lidocaine? 21. Chlorine was the first of the halogens to be isolated. C. W. Scheele carried out of the following reaction in 1774: 4NaCl (aq) + 2H2SO4 (aq) + mNo2 (s)  2Na2SO4 (aq) + MnCl2 (aq) +2H2O (l) +Cl2 (g). a) If you start with1.00 g NaCl and an excess of the other reactants, how many grams of Cl2 will be produced? b) If you start with 1.0 g H2SO4 and an excess of the other reactants, how many grams of Cl2 will be produced?

c) If you start with 1.0 g MnO2 and an excess of the other reactants, how many grams of Cl2 will be produced? d) How many grams of NaCl must react to produce 1.00 g Cl2 ? e) How many grams of H2SO4 must react to produce 1.00 g of Cl2? f) How many grams of MnO2 must react to produce1.00 g of Cl2? g) How many grams of Na2SO4 will be produced along with 1.00 g of Cl2? h) How many grams ofMnCl2 will be produced along with 1.00 g of Cl2? i) How many grams of H2O will be produced along with 1.00 Cl2? j) Show that the law of mass conservation is upheld in the production of 1.00 g Cl2.

22. Hematite (Fe2O3) is converted to molten iron in a blast furnace and is then poured into molds. The balanced equation is Fe2O3 (s) + 3CO (g)  2Fe (l) +3CO2 (g) a. b. c. d. e.

How many moles of Fe2O3 must react to produce 262 mol of Fe? How many moles of CO2 are produced by the reaction of 64.0 mol of CO? How many moles of Fe2O3 must react to produce 760 kg of Fe? How many grams of CO2 will be produced when 40.0 mol of CO react? What mass (in kg) of Fe is produced when 299 kg of Fe2O3 react?

23. Bleach is an aqueous solution of sodium Hypochlorite. A bleach solution may be prepared when chlorine gas is bubbled to aqueous sodium hydroxide to the