Chemistry A.P. Tutoring Quiz

CHEMISTRY A.P. TUTORING QUIZ

Reference elements and atomic weights:

H: 1.008 C: 12.01 N: 14.01 O: 16.00

F: 19.00 Ne: 20.18 Na: 22.99 Mg: 24.31

Al: 26.98

1) How many O atoms are there in 36.5 g of aluminum nitrate?

A) 1.15 x 1022 B) 9.29 x 1023 C) 4.65 x 1023

D) 2.81 x 1023 E) 5.89 x 1023

2) A newly installed water heater is filled to its full 120.0 L capacity. How much energy is required to heat the water from 25.0º C to 74.5º C? Assume the specific heat capacity of water is 4.18 J/g • ºC at 298 K.

A) 2.48 x 107 kJ B) 1.42 x 106 kJ C) 1.42 x 103 kJ

D) 2.48 x 10 kJ E) 2.48 x 104 kJ

3) What is the hybridization of the carbon atom in the molecule COCl2?

A) sp2d B) sp C) sp3

D) sp2 E) not hybridized

4) H2O2 is used as an oxygen source at a wastewater treatment plant. It decomposes according to the following reaction:

2 H2O2 (aq) → 2 H2O (l) + O2 (g)

What volume of oxygen at 25.0º C and 760 mmHg can be liberated from 30.0 g of H2O2? Assume R = 62.4 L•torr / K•mol.

A) 21.6 L B) 0.905 L C) 10.8 L

D) 43.2 L E) 0.0927 L

5) 0.125 g of sodium hydroxide is dissolved in water and the final volume is brought to 50.0 mL. What is the pH of the resulting solution?

A) 12.8 B) 1.20 C) 0.204

D) 13.8 E) 13.6

6) What is the balanced overall reaction given the following half reactions:

Al(s) → Al+3(aq) + 3e-

2H+(aq) + 2e- → H2(g)

A) Al(s) + 4 H+(aq) → Al+3(aq) + 2 H2(g) B) Al(s) + H2(aq) → Al+3(aq) + 2 H+(aq) + e-

C) Al(s) + 2 H+(aq) → Al+3(aq) + H2(g) + e- D) 2 Al(s) + 6 H+(aq) → 2 Al+3(aq) + 3 H2(g)

E) none of the above

7) A compound of an unknown formula has a molar mass of 97 g/mol. The composition is 73.1% chlorine, 24.8% carbon, and the rest is hydrogen. Which of the following is TRUE?

A) There are 2 moles of chlorine in every mole of the compound

B) The empirical formula is C2H2Cl2.

C) The molecular formula is CHCl.

D) The mole ratio of chlorine to carbon is approximately 3 to 1.

E) The empirical formula is CH2Cl.

8) Hydrobromic acid is mixed with a solution of sodium carbonate. Which of the following is NOT a product of the acidic reaction?

A) CO2 B) NaBr C) H2CO3

D) Br– ions E) H2O

9) What is the hybridization of the central atom and bond angle for BrF3?

A) sp3d, 120º B) sp3d, 90º C) sp2, 90º

D) sp2d2, 120º E) sp2, 120º

10) What is the molecular geometry for the compound in question 9 above?

A) Triangular pyramidal

B) T-shaped

C) Trigonal planar

D) Trigonal pyramidal

E) Trigonal bipyramidal

11) Sulfur burns to SO2 emitting a beautiful deep blue-purple flame, but with a foul odor:

2 S + O2 → 2 SO2. How many liters of oxygen gas are needed to form 35.2 L of SO2 at standard temperature and pressure?

A) 70.4 L B) 35.2 L C) 8.8 L

D) 26.4 L E) 17.6 L

12) The following equilibrium is reached when sodium cyanide solution is added to silver nitrate solution: Ag+(aq) + 2 CN–(aq) ⇌ Ag(CN)2–(aq). If Keq = 5.6 x 1018, which of the following is TRUE?

A) The equilibrium will be favored in the forward direction.

B) The equilibrium will be favored in the reverse direction.

C) The cyanide ion concentration will be greater than the silver cyanide concentration at equilibrium.

D) The silver cyanide concentration will be less than the silver nitrate concentration at equilibrium.

E) The silver ion concentration will be higher than all the other ions at equilibrium.

13) If 3.00 moles of helium gas and 3.00 moles of radon gas are compared at STP, the two gases, in terms of their particles, will have equal:

A) density B) volume C) rates of diffusion

D) probable velocities E) average molecular velocities

14) The chloride ion concentration of a saturated solution of silver chloride is 1.3 x 10–5 M. Calculate the Ksp for silver chloride.

A) 1.3 x 10–5 B) 1.7 x 10–5 C) 2.2 x 10–15

D) 1.7 x 10–10 E) 2.9 x 10–20

15) From the following chemical equations:

2 SO2(g) + O2(g) → 2 SO3(g) ∆Hºrxn = -197.8 kJ

2 NO(g) + O2 (g) → 2 NO2(g) ∆Hºrxn = -114.14 kJ

calculate ∆Hºrxn for the reaction:

SO2(g) + NO2(g) → SO3(g) + NO(g)

A) -311.9 kJ B) -83.66 kJ C) -41.83 kJ

D) -155.9 kJ E) +155.9 kJ

16) A solution containing 7.25 g of barium chloride is added to a second solution containing excess sodium sulfate; barium sulfate precipitates as a result. Calculate the theoretical yield of barium sulfate.

A) 7.57 g B) 6.47 g C) 8.12 g

D) 7.01 g E) 9.80 g

17) The reaction in question 16 is experimentally observed to result in an actual yield of 7.12 g of barium sulfate. Calculate the percent yield.

A) 98.5% B) 90.9% C) 94.1%

D) 87.7% E) 72.7%

18) Which of the following statements is NOT true?

A) Alpha particles are electrons being ejected from the nucleus.

B) Positron emission is a form of decay related to beta particle decay.

C) Beta particles are less energetic compared to nuclear decay involving gamma rays.

D) A nucleus can gain a proton as a result of nuclear decay.

E) Alpha particles have the same mass as a helium-4 nuclide.

19) Which of the following statements is TRUE?

A) NH3 is a strong electrolyte.

B) Acetic acid is a weak electrolyte.

C) Ethanol acts as a strong electrolyte.

D) Sulfuric acid is a weak electrolyte.

E) Hard tap water is a non-electrolyte.

20) An atom has 32 neutrons and 23 electrons. If it is a cation with a +2 charge, what is its correct symbol?

A) Mn+2 B) Sc+2 C) Cu+2

D) Mn+2 E) Sc+2

21) Carbon tetrachloride gas decomposes in the following reaction:

CCl4(g) → C(s, graphite) + 2 Cl2(g) ∆H = +95.7 kJ; ∆S = +142.2 J/K

Calculate ∆G at 25ºC and determine whether the reaction is spontaneous.

A) +28.5 x 106 J; spontaneous

B) +28.5 x 106 J; not spontaneous

C) +92.1 x 103 J; not spontaneous

D) +53.3 x 103 J; spontaneous

E) +53.3 x 103 J; not spontaneous

22) For the following redox reaction occurring in basic solution, what are the coefficients of the chlorite ions and oxygen molecules produced, respectively, when the reaction is balanced:

H2O2(aq) + ClO2(aq) → ClO2–(aq) + O2(g)

A) 1 and 2 B) 2 and 2 C) 2 and 1

D) 1 and 1 E) 2 and 4

23) For the following redox reaction occurring in acidic solution, what are the coefficients for the sulfate ions and water molecules produced, respectively, when the reaction is balanced:

SO3–2(aq) + MnO4–(aq) → SO4–2(aq) + Mn+2(aq)

A) 5 and 3 B) 5 and 6 C) 3 and 5

D) 4 and 4 E) 4 and 6

24) A cylinder filled with carbon dioxide expands against an external pressure of 1.58 atm, pushing a piston outward. If the initial gas volume is 0.485 L and the final volume is 1.245 L, how much work is done? Assume 101.3 J = 1 L•atm.

A) -1.18 x 10–2 J B) +1.20 J C) -1.20 J

D) -122 J E) +122 J