Chemistry I Exam 1 review Name: For the multiple choice problems, mark the correct answer on the scantron with the corresponding problem number. For the open ended problems, show your work on the test, and make certain units are present in all responses. 1. The distance between carbon atoms in ethylene is 134 picometers. Which of the following expresses that distance in meters? A) 1.34 10 13 m B) 1.34 10 12 m C) 1.34 10 10 m D) 1.34 10 7 m E) 1.34 10 6 m 2. A large pizza has a diameter of 15 inches. Express this diameter in centimeters. A) 38 cm B) 24 cm C) 18 cm D) 9.3 cm E) 5.9 cm 3. A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H 2 SO 4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? (Assume water has a density of 1.00 g/cm 3 at the temperature of the measurement.) A) 1.992 g/cm 3 B) 1.840 g/cm 3 C) 1.729 g/cm 3 D) 1.598 g/cm 3 E) 0.543 g/cm 3 4. Acetone, which is used as a solvent and as a reactant in the manufacture of Plexiglas, boils at 56.1 C. What is the boiling point in degrees Fahrenheit? A) 159 F B) 133 F C) 101 F D) 69.0 F E) 43.4 F Page 1
5. Isopropyl alcohol, commonly known as rubbing alcohol, boils at 82.4 C. What is the boiling point in kelvins? A) 387.6 K B) 355.6 K C) 323.6 K D) 190.8 K E) 190.8 K 6. Select the answer that expresses the result of this calculation with the correct number of significant figures. 13.602 1.90 3.06 = 4.2 1.4097 A) 13.3568 B) 13.357 C) 13.36 D) 13.4 E) 13 7. Express 96,342 m using 2 significant figures. A) 9.60 10 4 m B) 9.6 10 4 m C) 9.60 10-4 m D) 9.6 10-4 m E) 96000. m 8. Kaolinite, a clay mineral with the formula Al 4 Si 4 O 10 (OH) 8, is used as a filler in slick-paper for magazines and as a raw material for ceramics. Analysis shows that 14.35 g of kaolinite contains 8.009 g of oxygen. Calculate the mass percent of oxygen in kaolinite. A) 1.792 mass % B) 24.80 mass % C) 30.81 mass % D) 34.12 mass % E) 55.81 mass % Page 2
9. Iodine pentafluoride reacts slowly with glass and violently with water. Determine its molecular mass. A) 653.52 amu B) 259.89 amu C) 221.90 amu D) 202.90 amu E) 145.90 amu 10. Which one of the following combinations of names and formulas is incorrect? A) H 3 PO 4 phosphoric acid B) HNO 3 nitric acid C) NaHCO 3 sodium carbonate D) H 2 CO 3 carbonic acid E) KOH potassium hydroxide 11. What is the name of the acid formed when HClO 4 liquid is dissolved in water? A) hydrochloric acid B) perchloric acid C) chloric acid D) chlorous acid E) hydrochlorate acid 12. Iron (III) chloride hexahydrate is used as a coagulant for sewage and industrial wastes. What is its formula? A) Fe(Cl 6H 2 O) 3 B) Fe 3 Cl 6H 2 O C) FeCl 3 (H 2 O) 6 D) Fe 3 Cl(H 2 O) 6 E) FeCl 3 6H 2 O 13. The substance, KClO 3, is a strong oxidizer used in explosives, fireworks, and matches. What is its name? A) potassium chlorite B) potassium chloride C) potassium(i) chlorite D) potassium(i) chlorate E) potassium chlorate Page 3
14. Calculate the molar mass of (NH 4 ) 3 AsO 4. A) 417.80 g/mol B) 193.03 g/mol C) 165.02 g/mol D) 156.96 g/mol E) 108.96 g/mol 15. Magnesium fluoride is used in the ceramics and glass industry. What is the mass of 1.72 mol of magnesium fluoride? A) 43.3 g B) 62.3 g C) 74.5 g D) 92.9 g E) 107 g 16. Potassium dichromate, K 2 Cr 2 O 7, is used in tanning leather, decorating porcelain and water proofing fabrics. Calculate the number of chromium atoms in 78.82 g of K 2 Cr 2 O 7. A) 9.490 10 25 Cr atoms B) 2.248 10 24 Cr atoms C) 1.124 10 24 Cr atoms D) 3.227 10 23 Cr atoms E) 1.613 10 23 Cr atoms 17. Calculate the mass in grams of 8.35 10 22 molecules of CBr 4. A) 0.0217 g B) 0.139 g C) 7.21 g D) 12.7 g E) 46.0 g Page 4
21. In the combustion analysis of 0.1127 g of glucose (C 6 H 12 O 6 ), what mass, in grams, of CO 2 would be produced? A) 0.0451 g B) 0.0825 g C) 0.1652 g D) 0.4132 g E) 1.466 g Open ended problems: SHOW YOUR WORK! 27. An evacuated 276 ml glass bulb weighs 129.6375 g. Filled with an unknown gas, the bulb weighs 130.0318 g. Calculate the gas density in g/l, and express it with an appropriate number of significant figures. Page 5
28. Fill in the blank spaces and write out all the symbols in the left hand column in full,in the A form Z X (i.e. include the appropriate values of Z and A as well as the correct symbol X). Symbol # protons # neutrons # electrons 17 18 Au 118 20 20 29. a. Give the names of the following ions: (i) NH 4 + (ii) SO 3 2- b. Write down the formulas of the following ions: (i) aluminum (ii) carbonate 30. For each of the following names, write down the corresponding formula, including charge where appropriate (atomic numbers and mass numbers are not required): a. zinc ion b. nitrite ion c. carbonic acid d. cyanide ion 31. For each of the following elements, indicate next to the symbol whether it is a metal, a non-metal or a metalloid: a. S b. Ge c. Hg d. H e. I f. Si Page 6
35 17 Cl 17 18 17 Answer Key 1. C 2. A 3. B 4. B 5. B 6. E 7. B 8. E 9. C 10. C 11. B 12. E 13. E 14. B 15. E 16. D 17. E 18. A 19. B 20. D 21. C 22. A 23. C 24. C 25. A 26. a. 0.0444 mol DDT b. Chlorobenzene is the limiting reagent. c. 77.2% 27. 1.43 g/l 28. Symbol # protons # neutrons # electrons 197 79 Au 40 20 Ca 29. a. (i) ammonium (ii) sulfite b. (i) Al 3+ (ii) CO 3 2-30. a. Zn 2+ b. NO 2 - c.h 2 CO 3 d.cn - 79 20 118 20 79 20 Page 7
31. a. nonmetal b. metalloid c. metal d. nonmetal e. nonmetal f. metalloid Page 8