ACP Chemistry Exam 2: Chapters 4, 5 & 15

Name: ______Period: _____ Date: ______This exam is worth 90 points with each correct response worth 2 points. Only those exams completed in black ink will be graded. Good luck!

1) According to the following balanced reaction, how many moles of NO are formed from 8.44 moles of NO2 if there is plenty of water present?

3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g)

A) 2.81 moles NO B) 25.3 moles NO C) 8.44 moles NO D) 5.63 moles NO E) 1.83 moles NO

2) Consider the following balanced reaction. How many grams of water are required to form 75.9 g of HNO3? Assume that there is excess NO2 present. The molar masses are as follows: H2O = 18.02 g/mol, HNO3 = 63.02 g/mol.

3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g)

A) 38.0 g H2O B) 21.7 g H2O C) 43.4 g H2O D) 10.9 g H2O E) 26.5 g H2O

3) Determine the theoretical yield of HCl if 60.0 g of BCl3 and 37.5 g of H2O are reacted according to the following balanced reaction. A possibly useful molar mass is BCl3 = 117.16 g/mol.

BCl3(g) + 3 H2O(l) → H3BO3(s) + 3 HCl(g)

A) 75.9 g HCl B) 132 g HCl C) 187 g HCl D) 56.0 g HCl E) 25.3 g HCl

1 4) Determine the percent yield of a reaction that produces 28.65 g of Fe when 50.00 g of Fe2O3 react with excess Al according to the following reaction.

Fe2O3(s) + 2 Al(s) → Al2O3(s) + 2 Fe(s) A) 61.03 % B) 28.65 % C) 57.30 % D) 20.02 % E) 81.93 %

5) Determine the concentration of a solution prepared by diluting 25.0 mL of a stock 0.188 M Ca(NO3)2 solution to 150.0 mL. A) 1.13 M B) 0.0887 M C) 0.0313 M D) 0.0199 M E) 0.0501 M

6) What mass (in g) of AgCl is formed from the reaction of 75.0 mL of a 0.078 M AgC2H3O2 solution with 55.0 mL of 0.109 M MgCl2 solution?

2 AgC2H3O2(aq) + MgCl2(aq) → 2 AgCl(s) + Mg(C2H3O2)2(aq)

A) 0.838 g B) 1.72 g C) 0.859 g D) 2.56 g E) 1.70 g

7) Which of the following is considered a STRONG electrolyte? A) NH4NO3 B) C12H22O11 C) PbCl2 D) HC2H3O2 E) CH3OH

8) Which of the following compounds is soluble in water? A) CaS B) MgCO3 C) PbCl2 D) BaSO4 E) None of these compounds is soluble in water.

2 9) Which of the following pairs of aqueous solutions will form a precipitate when mixed? A) NH4NO3 + Li2CO3 B) Hg2(NO3)2 + LiI C) NaCl + Li3PO4 D) AgC2H3O2 + Cu(NO3)2 E) None of the above solution pairs will produce a precipitate.

10) Give the complete ionic equation for the reaction (if any) that occurs when aqueous solutions of lithium sulfide and copper (II) nitrate are mixed. A) Li+ (aq) + SO42-(aq) + Cu+(aq) + NO3-(aq) → CuS(s) + Li+(aq) + NO3-(aq) B) Li+ (aq) + S-(aq) + Cu+(aq) + NO3-(aq) → CuS(s) + LiNO3(aq) C) 2 Li+(aq) + S2-(aq) + Cu2+(aq) + 2 NO3-(aq) → Cu2+(aq) + S2-(aq) + 2 LiNO3(s) D) 2 Li+(aq) + S2-(aq) + Cu2+(aq) + 2 NO3-(aq) → CuS(s) + 2 Li+(aq) + 2 NO3-(aq) E) No reaction occurs.

11) Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of Na2CO3 and HCl are mixed. A) 2 H+(aq) + CO32-(aq) → H2CO3(s) B) 2 Na+(aq) + CO32-(aq) + 2 H+(aq) + 2 Cl-(aq) → H2CO3(s) + 2 NaCl(aq) C) 2 H+(aq) + CO32-(aq) → H2O(l) + CO2(g) D) 2 Na+(aq) + CO32-(aq) + 2 H+(aq) + 2 Cl-(aq) → H2CO3(s) + 2 Na+(aq) + 2 Cl-(aq) E) No reaction occurs.

12) Which of the following is an acid base reaction? A) C(s) + O2(g) → CO2(g) B) 2 HClO4(aq) + Ca(OH)2(aq) → 2 H2O(l) + Ca(ClO4)2(aq) C) Fe(s) + 2 AgNO3(aq) → 2 Ag(s) + Fe(NO3)2(aq) D) MgSO4(aq) + Ba(NO3)2(aq) → Mg(NO3)2(aq) + BaSO4(s) E) None of the above are acid base reactions.

13) The titration of 25.0 mL of an unknown concentration H2SO4 solution requires 83.6 mL of 0.12 M LiOH solution. What is the concentration of the H2SO4 solution (in M)? A) 0.20 M B) 0.40 M C) 0.10 M D) 0.36 M E) 0.25 M

3 14) Determine the oxidation state of P in PO33-. A) +3 B) +6 C) +2 D) 0 E) -3

15) Determine the oxidizing agent in the following reaction.

Ni(s) + 2 AgClO4(aq) → Ni(ClO4)2(aq) + 2 Ag(s)

A) Ag B) Ni C) Cl D) O E) This is not an oxidation-reduction reaction.

16) The volume of a gas is proportional to the temperature of a gas is known as A) Avogadro's Law B) Ideal Gas Law C) Charles's Law D) Boyle's Law E) Dalton's Law

17) What volume will a balloon occupy at 1.0 atm, if the balloon has a volume of 7.6 L at 3.8 atm? A) 2.0 L B) 5.0 L C) 29 L D) 35 L E) 17 L

18) If a sample of 0.29 moles of Ar occupies 3.8 L under certain conditions, what volume will 0.66 moles occupy under the same conditions? A) 12 L B) 8.6 L C) 17 L D) 5.0 L E) 15 L

4 19) A syringe initially holds a sample of gas with a volume of 285 mL at 355 K and 1.88 atm. To what temperature must the gas in the syringe be heated/cooled in order to have a volume of 435 mL at 2.50 atm? A) 139 K B) 572 K C) 175 K D) 466 K E) 721 K

20) What is the volume of 9.783 x 1023 atoms of He at 9.25 atm and 512K? A) 7.38 L B) 3.69 L C) 1.85 L D) 15.4 L E) 30.8 L

21) Which of the following gas samples would be most likely to behave ideally under the stated conditions? A) Ne at STP B) CO at 200 atm and 25°C C) SO2 at 2 atm and 0 K D) N2 at 1 atm and -70°C E) O2 at 400 atm and 25°C

22) Using the graph below, determine the gas that has the lowest density at STP.

A) A B) B C) C D) D E) All of the gases have the same density at STP.

5 23) The density of a gas is 1.43 g/L at STP. What is the gas? A) Cl2 B) S C) O2 D) Ne E) None of the above

24) In a container containing CO, H2, and O2, what is the mole fraction of CO if the H2 mole fraction is 0.22 and the O2 mole fraction is 0.58? A) 0.20 B) 0.30 C) 0.10 D) 0.50 E) 0.88

25) A mixture of 0.220 moles CO, 0.350 moles H2 and 0.640 moles He has a total pressure of 2.95 atm. What is the pressure of CO? A) 1.86 atm B) 0.649 atm C) 0.536 atm D) 1.54 atm E) 0.955 atm

26) Determine the volume of SO2 (at STP) formed from the reaction of 96.7 g of FeS2 and 55.0 L of O2 (at 398 K and 1.20 atm). The molar mass of FeS2 is 119.99 g/mol.

4 FeS2(s) + 11 O2(g) → 2 Fe2O3(s) + 8 SO2(g)

A) 36.1 L B) 45.3 L C) 18.1 L D) 27.6 L E) 32.9 L

27) Identify the gas particle that travels the slowest. A) H2 B) O2 C) Ne D) N2 E) CO

6 28) Which of the following compounds will behave LEAST like an ideal gas at low temperatures? A) He B) SO2 C) H2 D) N2 E) F2

29) Which of the following samples will have the greatest average speed at 355 K? A) Ne B) C2H4 C) Cl2 D) CH4 E) All of these samples will have the same average speed at the same temperature.

30) This equation is used to calculate the properties of a gas under nonideal conditions. A) Charles's Law B) Avogadro's Law C) Boyle's Law D) van der Waals equation E) Dalton's Law

31) Identify the acid that is in vinegar. A) H2SO4 B) HNO3 C) H2CO3 D) CH3COOH E) HF

32) Which of the following is an Arrhenius acid? A) H2SO4 B) LiOH C) NH2CH3 D) CH3CH3 E) More than one of these is an Arrhenius acid.

33) Which of the following is a Bronsted-Lowry base? A) CH4 B) HCN C) NH3 D) Cl2 E) None of the above are Bronsted-Lowry bases.

7 34) Which of the following species is amphoteric? A) CO32- B) HF C) NH4+ D) HPO42- E) None of the above are amphoteric.

35) The stronger the acid, then which of the following is TRUE? A) The stronger the conjugate acid. B) The stronger the conjugate base. C) The weaker the conjugate base. D) The weaker the conjugate acid. E) None of the above.

36) What is the pH of pure water at 40.0°C if the Kw at this temperature is 2.92 × 10-14? A) 6.767 B) 0.465 C) 7.000 D) 7.233 E) 8.446

37) Calculate the pH of a solution that contains 2.4 × 10-5 M H3O+ at 25°C. A) 2.40 B) 9.38 C) 4.62 D) 11.60 E) 4.17

38) Calculate the hydroxide ion concentration in an aqueous solution with a pH of 9.85 at 25°C. A) 7.1 × 10-5 M B) 4.2 × 10-10 M C) 8.7 × 10-10 M D) 6.5 × 10-5 M E) 1.4 × 10-10 M

39) Which of the following acids is the WEAKEST? The acid is followed by its Ka value. A) HC2H3O2, 1.8 × 10-5 B) HIO, 2.3 × 10-11 C) HBrO, 2.3 × 10-9

8 D) HClO, 2.9 × 10-8 E) C6H5CO2H, 6.3 × 10-5 40) Determine the pH of a 0.188 M NH3 solution at 25°C. The Kb of NH3 is 1.76 × 10-5. A) 5.480 B) 2.740 C) 8.520 D) 11.260 E) 12.656

41) Which one of the following will form an acidic solution in water? A) NH4Cl B) NaF C) LiI D) KNO3 E) None of the above solutions will be acidic.

42) In a triprotic acid, which Ka has the highest value? A) Ka1 B) Ka2 C) Ka3 D) Kb1 E) Kb2

43) Identify the strongest acid. A) H2O B) H2S C) H2Se D) H2Te E) not enough information is available

44) Which of the following is a polyprotic acid? A) HF B) H2SO4 C) HCN D) CH4 E) HC2H3O2

45) Determine the pH of a 0.18 M H2CO3 solution. Carbonic acid is a diprotic acid whose Ka1 = 4.3 × 10-7 and Ka2 = 5.6 × 10-11. A) 11.00 B) 10.44 C) 5.50 D) 4.31

9 E) 3.56