Practice Midterm 1 Chem 001B PDF

CHEM 001B EXAM COVER SHEET 20 multiple choice questions worth 7.5 points each Time: 70 minutes Instructions (read carefully) Write your name, NetID, TA Name, and Section number on the bubble sheet. Make sure to bubble in your exam version (A, B, or C) on the bubble sheet. Bubble in your an...

CHEM 001B EXAM COVER SHEET 20 multiple choice questions worth 7.5 points each Time: 70 minutes Instructions (read carefully) Write your name, NetID, TA Name, and Section number on the bubble sheet. Make sure to bubble in your exam version (A, B, or C) on the bubble sheet. Bubble in your answer to each question directly on the bubble sheet. Answers written on the exam itself will not be graded. No cell phones, tablets, laptops, or wireless devices other than a calculator are allowed during exam. Use of a prohibited device will result in a zero for the exam. If you need to use the restroom, hand in your cell phone and exam materials to a TA. When time is called, stop writing immediately, and turn in your exam to your specific TA at the front of room. Show your UCR ID to the TA once you hand in your exam. You may rip off this cover page. Equations: C1V1 = C2V2 PV = nRT P = F/A [P + a(n/V)2](V-nb) = nRT Ptotal = PA+PB +PC d = µP/RT PA = Xi·Ptotal RateA/RateB = sqrt(µB/µA) Xi = ni/ntotal KEavg = ½µνrms2 P1V1/T1 = P2V2/T2 νrms = sqrt(3RT/µ) Constants and units: 101.3 J = 1 L atm 1 atm = 760 mmHg = 760 Torr M = mol solute / L solution 1 atm = 14.7 psi R = 0.0821 L·atm/mol·K = 8.31 J/mol·K 1 L = 1000 cm3 = 8.314 kg·m2/s2·mol·K 0˚C = 273.15 K  Name Version A B C D E ID Other Section Marking Instructions Be sure to completely fill in the ap- Example propriate bubble. A B C D E Date A B C D E A B C D E A B C D E A B C D E 1 A B C D E 26 A B C D E 51 A B C D E 76 A B C D E 2 A B C D E 27 A B C D E 52 A B C D E 77 A B C D E 3 A B C D E 28 A B C D E 53 A B C D E 78 A B C D E 4 A B C D E 29 A B C D E 54 A B C D E 79 A B C D E 5 A B C D E 30 A B C D E 55 A B C D E 80 A B C D E 6 A B C D E 31 A B C D E 56 A B C D E 81 A B C D E 7 A B C D E 32 A B C D E 57 A B C D E 82 A B C D E 8 A B C D E 33 A B C D E 58 A B C D E 83 A B C D E 9 A B C D E 34 A B C D E 59 A B C D E 84 A B C D E 10 A B C D E 35 A B C D E 60 A B C D E 85 A B C D E 11 A B C D E 36 A B C D E 61 A B C D E 86 A B C D E 12 A B C D E 37 A B C D E 62 A B C D E 87 A B C D E 13 A B C D E 38 A B C D E 63 A B C D E 88 A B C D E 14 A B C D E 39 A B C D E 64 A B C D E 89 A B C D E 15 A B C D E 40 A B C D E 65 A B C D E 90 A B C D E 16 A B C D E 41 A B C D E 66 A B C D E 91 A B C D E 17 A B C D E 42 A B C D E 67 A B C D E 92 A B C D E 18 A B C D E 43 A B C D E 68 A B C D E 93 A B C D E 19 A B C D E 44 A B C D E 69 A B C D E 94 A B C D E 20 A B C D E 45 A B C D E 70 A B C D E 95 A B C D E 21 A B C D E 46 A B C D E 71 A B C D E 96 A B C D E 22 A B C D E 47 A B C D E 72 A B C D E 97 A B C D E 23 A B C D E 48 A B C D E 73 A B C D E 98 A B C D E 24 A B C D E 49 A B C D E 74 A B C D E 99 A B C D E 25 A B C D E 50 A B C D E 75 A B C D E 100 A B C D E Bubble Sheet v2020.05.01 Page 1 Name: ______________________ Class: _________________ Date: _________ ID: B Practice Midterm 1 Multiple Choice Identify the choice that best completes the statement or answers the question. ____ 1. Balance the following redox reaction under acidic aqueous conditions using the smallest whole-number coefficients possible. What is the coefficient of HSO3 −? 2+ 3− MnO4−(aq) + HSO3−(aq) → Mn (aq) + SO4 (aq) a. 3 d. 2 b. 5 e. 10 c. 1 ____ 2. Stomach acid is approximately 0.10 M HCl. How many mL of stomach acid can be neutralized by one regular antacid tablet that contains 500 mg of solid CaCO3 (100.09 g/mol)? Recall that carbonate anions can react with two equivalents of acid. a. 50 mL d. 100 mL b. 200 mL e. 500 mL c. 1000 mL ____ 3. Select the net ionic equation for the reaction of rubidium hydroxide with nitric acid. + a. Rb OH(aq) → Rb (aq) + OH − (aq) + b. H (aq) + OH − (aq) → H 2 O(™) + + c. Rb (aq) + OH − (aq) + H (aq) + NO 3− (aq) → H 2 O(™) + RbNO 3 (aq) + d. HNO 3 (aq) → H (aq) + NO 3− (aq) + e. Rb (aq) + NO 3− (aq) → RbNO3 (aq) ____ 4. In which of the following does manganese have the highest oxidation number? a. Mn(NO3 ) 2 d. K2 MnO4 b. MnO2 e. Ba(MnO4 ) 2 c. MnF3 ____ 5. Which of the following represents the maximum mercury levels in drinking water, which is approximately 2 ppb? Assume the density of drinking water is 1 g/mL. a. 10 µM d. 1 nM b. 1 µM e. 10 nM c. 20 pM 1 Name: ______________________ ID: B ____ 6. The thermite reaction is used in welding applications and chemistry demonstrations because it releases a tremendous amount of energy. Which of the following statements is NOT correct regarding this reaction? 8 Al(s) + 3 Fe3O4 (s) → 9 Fe(s) + 4 Al 2 O3(s) a. The oxidation number of Al changes from 0 to +3. b. Aluminum is the reducing agent. c. Iron is reduced. d. Electrons are transferred only from the aluminum atoms to the oxygen atoms. e. Aluminum is oxidized. ____ 7. Suppose 3.95% of 521 g of PCl5 (208.2 g/mol) initially present in a 10.0 L reaction vessel at 300°C decomposes to form PCl3 (137.3 g/mol) and Cl2 (70.90 g/mol). What is the resulting pressure of PCl3 ? PCl 5 (g) → PCl 3 (g) + Cl 2 (g) a. 4.66 atm d. 0.243 atm b. 6.15 atm e. 11.8 atm c. 0.465 atm ____ 8. During the decomposition of KClO3 (s) into KCl(s) and O2 (g), 100.0 mL of gas is collected by the displacement of water in a flask at 25°C with an atmospheric pressure of 755 mmHg. The vapor pressure of water at this temperature is 23.8 mmHg. What mass of O2 is collected? a. 0.679 mg d. 0.807 mg b. 21.7 mg e. 12.9 mg c. 126 mg ____ 9. The following graph shows the distribution of molecular speeds for CO2 at four different temperatures. Which of the curves corresponds to the lowest temperature? a. A d. More information is needed. b. C e. B c. D 2 Name: ______________________ ID: B ____ 10. N2 O (laughing gas) is used as an anesthetic. A dentist has a 2.00 L flask of N2 O at a pressure of 1.00 atm and a 3.00 L flask of nitrogen gas at 2.00 atm that are separated by a valve. What is the final pressure in the flasks when the valve is opened and the gases mix together? Both flasks are at the same temperature, and the temperature does not change when the gases mix. a. 1.60 atm d. 3.00 atm b. 1.50 atm e. 1.00 atm c. 1.20 atm ____ 11. A sample of argon gas at 2.90 atm and 35.0 mL is heated from 20.0°C to 50.0°C. If the pressure remains constant, what is the final volume of the gas? a. 87.5 mL d. 31.8 mL b. 35.0 mL e. 38.6 mL c. 52.5 mL ____ 12. The van der Waals constants for NO2 are a = 5.28 L2 ⋅ atm/mol2 and b = 0.04424 L/mol. What is the pressure of 2.00 mol of NO2 in a 3.00 L container at 173.15 K when the gas is treated as real? a. 6.24 atm d. 9.47 atm b. 7.42 atm e. 9.76 atm c. 12.1 atm ____ 13. In an experiment, hydrogen sulfide gas is collected in a 1.25 L flask at 21.0°C and 758 torr. How many grams of H2 S (34.08 g/mol) are obtained? a. 1.76 g d. 1.36 g b. 39.3 g e. 24.7 g c. 0.0517 g ____ 14. What is the density of sulfur hexafluoride (SF6 , 146.1 g/mol) in a cylinder at 1.5 atm and 22°C? a. 0.062 g/L d. 16 g/L b. 0.11g/L e. 9.1 g/L c. 0.83 g/L ____ 15. What is the root-mean-square speed of HF at 37.5°C? a. 216 m/s d. 622 m/s b. 6.84 m/s e. 61.8 m/s c. 19.7 m/s ____ 16. Silver salts are used in black-and-white photography. Ag+ ions left in developing solutions are often collected by precipitation reactions. A 4.5 L bottle of a developing solution was treated with an excess of sodium chloride, and 2.86 g of dry silver chloride was collected. What was the molar concentration of the silver ions in the developing solution? −3 a. 2.9 M d. 4.4 × 10 M −3 b. 5.9 × 10 M e. 4.4 M −3 c. 2.9 × 10 M 3 Name: ______________________ ID: B ____ 17. Balance the following redox reaction under acidic aqueous conditions using the smallest whole-number coefficients possible. On which side does H2 O(l) appear, and what is its coefficient? 2+ MnO4 −(aq) + I −(aq) → I 2 (aq) + Mn (aq) a. left; 16 d. right; 8 b. right; 16 e. right; 4 c. left; 8 ____ 18. Which expression best represents the ionization of formic acid, HCO2 H, in water? + a. HCO2 H(aq) + H 2 O(™) → HCO 3− (aq) + H (aq) + b. HCO2 H(aq) + H 2 O(™) → CO 2− (aq) + 2 H 3 O (aq) + c. HCO 2 H(aq) + 2 H 2 O(™) H 2CO 3 (aq) + H3 O (aq) + d. HCO2 H(aq) + H 2O(™) → CO2 (aq) + H3 O (aq) + e. HCO2 H(aq) + H2 O(™) HCO2− (aq) + H3 O (aq) ____ 19. Which of the following items does NOT characterize an oxidizing agent? a. An oxidizing agent gains electrons. b. An oxidizing agent causes another species to be oxidized. c. The oxidation number of an oxidizing agent decreases. d. A good oxidizing agent is a metal in a high oxidation state, such as Mn7 +. e. An example of a good oxidizing agent is an alkali metal, such as Na. ____ 20. What is the oxidizing agent in the reaction 2 NO2 (g) + O3(g) → N2O5 (s) + O2 (g)? a. NO2 d. O2 b. O3 e. This is not a redox reaction. c. N2 O5 4