Midterm Exam 1 C. a) Midterm 1 A b) Midterm 1 B c) Midterm 1 C d) Midterm 1 D e) Midterm 1 E

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1 1. Which Exam are you taking? Midterm Exam 1 C a) Midterm 1 A b) Midterm 1 B c) Midterm 1 C d) Midterm 1 D e) Midterm 1 E 2. Which of the following organic compounds has the lowest molecular weight? (Atomic weights: C = 12.01, O = 16.00, F = 19.00, H = 1.008) a) C 4 H 8 F 2 O 2 b) C 3 H 5 F 3 O 2 c) C 5 H 8 FO 2 d) C 4 H 7 FO 3 e) C 3 H 6 F 2 O 3 3. A sample of the compound M 2 SO 4 weighing g reacts with BaCl 2 to give g BaSO 4. What is the atomic weight of the element M? (Atomic weights: S = 32.06, O = 16.00, Ba 137.3) a) 6.94 b) 23.0 c) 39.1 d) 24.3 e)

2 4. Silicon (atomic weight ) has three naturally-occurring isotopes with isotopic weights , and The abundance of the lightest isotope is 92.21%. What is the percentage abundance of the heaviest isotope? a) 6.3 b) 5.2 c) 3.9 d) 3.1 e) What is the chemical name of Sc 2 (CrO 4 ) 3? a) scandium (II) chromate b) scandium (II) dichromate c) scandium (III) chromate d) scandium (III) dichromate e) scandium (II) chromite 6. What is the symbol for the bisulfite ion? a) HSO 4 b) HSO 3 c) HSO 3 2 d) HSO 4 2 e) H 2 SO 4 2

3 32 7. The species 16 S2- contains: a) 16 protons and 18 neutrons b) 18 protons and 16neutrons c) 16 protons and 18 electrons d) 18 electrons and 32 neutrons e) 16 protons and 16 electrons 8. Which of the following samples has the largest mass? a) 25 g lead (density = 11.3 g/cm 3 ) b) 15 cm 3 aluminum (density = 2.70 g/cm 3 ) c) 4.0 cm 3 chromium (density = 7.20 g/cm 3 ) 9. Oil spreads on water to form a film 110 nm thick. How many square kilometers of ocean will be covered by a slick formed from one barrel of oil (126 liters)? a) 1.15 b) 1.15 x 10 6 c) 1.15 x 10 4 d) 1.15 x 10 2 e) 1.15 x

4 10. A crucible is known to weigh g. Three students in the class determine the weight of the crucible by repeated weighing on a simple balance. Using the following information, which student has done the most precise determination? Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 a) b) c) Do the indicated arithmetic and give the answer to the correct number of significant figures. ( x 54.6) a) 1.0 b) 1.01 c) d) e) Gases and liquids share the property of. a) Compressibility b) Definite volume c) Incompressibility d) Indefinite shape e) Definite shape 4

5 13. Which one of the following is not an intensive property? a) Density b) Temperature c) Melting point d) Mass e) Boiling mass 14. The name of PCl 3 is. a) Potassium chloride b) Phosphorus trichloride c) Phosphorous (III) chloride d) Monophosphorous trichloride e) Trichloro potassium 15. When aqueous solutions of are mixed, a precipitate forms. a) NiBr 2 and AgNO 3 b) NaI and KBr c) K 2 SO 4 and CrCl 3 d) KOH and KNO 3 e) Li 2 CO 3 and NaI 5

6 16. Based on the activity series, which one of the reactions below will occur? a) Zn (s) + MnI 2 (aq) ZnI 2 (aq) + Mn (s) b) SnCI 2 (aq) + Cu (s) Sn (s) + CuCI 2 (aq) c) 2AgNO 3 (aq) + Pb (s) 2Ag (s) + Pb(NO 3 ) 2 (aq) d) 3Hg (1) + 2Cr(NO 3 ) 3 (aq) 3Hg(NO 3 ) 2 + 2Cr (s) 17. The spectator ions in the reaction between aqueous perchloric acid and aqueous barium hydroxide are. a) OH and CIO 4 b) H +,OH,CIO 4, and Ba 2+ c) H + and OH - d) H + and Ba 2+ e) CIO 4 and Ba Which are the following are weak electrolytes? 1) HCl 2) HC 2 H 3 O 2 3)NH 3 4) KCl a) HCl, KCl b) HCl, HC 2 H 3 O 2, NH 3, KCl c) HC 2 H 3 O 2, NH 3, KCl d) HC 2 H 3 O 2, NH 3 e) HCl, HC 2 H 3 O 2, KCl 6

7 19. Crystalline potassium hydrogen phthalate KHC 8 H 4 O 4 is used to standardize basic solutions. If g of this salt is titrated with a solution of Ca(OH) 2, the end point is reached when ml of the solution has been added. What is the molarity of the Ca(OH) 2 solution? (Atomic weights: C = 12.01, O = 16.00, H = 1.008, Ca = 40.08, K = 39.10) 2 KHC 8 H 4 O 4 + Ca(OH) 2 Ca(KC 8 H 4 O 4 ) H 2 O a) x 10-2 b) x 10-2 c) x 10-2 d) x 10-1 e) x Determine the mass (g) of solute required to form ml of a M MgCl 2. (Atomic weights: Mg = 24.30, Cl = 35.45) a) 19.8 b) 21.1 c) 22.8 d) 24.2 e) The equation for the reduction of iron ore in a blast furnace is given below. How many kilograms of iron can be produced by the reaction of 7.00 kg of Fe 2 O 3 and 3.00 kg of CO? (Atomic weights: Fe = 55.85, O = 16.00, C = 12.01) Fe 2 O CO 2 Fe + 3 CO 2 a) 3.65 b) 3.98 c) 4.20 d) 4.32 e)

8 22. Balance the following equation. What is the sum of the coefficients of the reactants and products? I 2 O 5 + BrF 3 IF 5 + O 2 + Br 2 a) 25 b) 32 c) 45 d) 56 e) During naval battle in the South Pacific in WW2, the U.S. navy produced smokescreens by spraying titanium tetrachloride into the moist air to produce TiO 2. How many grams of TiO 2 are produced from 14.4 moles of TiCl 4? (Atomic weights: Ti = 47.90, O = 16.00) TiCl H 2 O TiO HCl a) 5.68 b) 79.9 c) 5.75 x 10 2 d) 1.15 x 10 3 e) 2.30 x A package of aluminum foil contains 12 ounces of aluminum ( 1 oz = 28.4 g). How many moles of aluminum atoms are in the package? (Atomic weight: Al = 26.98) a) 1.2 b) 4.5 c) 0.45 d) 12 e) 13 8

9 25. Aziridine contains only carbon, hydrogen and nitrogen. When a g sample is burned completely in oxygen, g of CO 2 and g of H 2 O are formed. What is the empirical formula? (Atomic weights: C = 12.01, H = 1.008, O = 16.00, N = 14.01) a) C 2 H 3 N b) C 2 H 4 N c) CHN d) C 2 H 4 N 3 e) C 3 H 6 N 26. An oxide of lead is converted by hydrogen gas to lead metal and water. One mole of the oxide reacts with 8.1 g of H 2 and forms 622 g of lead. What is the empirical formula of the oxide? (Atomic weights: Pb = 207.2, O = 16.00, H = 1.008) a) PbO b) PbO 2 c) PbO 3 d) Pb 3 O 4 e) Pb 2 O 5 9