Directions: Nongraphing calculators are permitted for the Chemistry individual exam. Graphing and programmable calculators are NOT allowed. Prohibited calculators include but are not limited to TI- Nspire, TI-84 Plus Silver edition, TI-83 Plus, and TI-89. For all questions select the answer that best fits the questions using correct significant figures where appropriate. For all questions, NOTA represents none of the above answers is correct. 1) What is the coefficient of O 2 (g) when the following equation is balanced? C 2 H 6 (g) + O 2 (g) CO 2 (g) + H 2 O (g) a) 1 b) 3 c) 5 d) 7 2) What is the percent yield of the reaction if 18.20 g nitrogen gas with excess hydrogen produces 11.25 g NH 3 (g)? N 2 (g) + 3 H 2 (g) 2 NH 3 (g) a) 11.45% b) 50.83% c) 62.91% d) 82.25% 3) The distance from the earth to the moon is 250,000 miles. Calculate the in meters 1km = 0.62137 mi a) 402,336,771.97 m b) 4.0 X 10 8 m c) 402 million meters d) 402 thousand meters 4) Which of the following molecules is the most soluble in H2O? a) CH3CH2OH b) CH3OCH3 c) CH3CH2Cl d) CH3CH2CH3 5) The decomposition of N 2 O to nitrogen and oxygen is zero order with a rate constant, k = 0.0150 M s -1. If the initial concentration of N 2 O is 0.224 M, what would be [N 2 O] after 10 seconds? a) 0.185 M b) 0.209 M c) 0.0740 M d) 0.0922 M 6) Which one of the following pairs cannot be mixed together to form a buffer solution? a) NH 3, NH 4 Cl b) NH 3, NaOH c) HF, NaF d) HF, NaOH Page 1 of 7
7) When a copper pipe is heated with a torch, copper oxide forms and its color changes to black: a) This is only a chemical change b) This is only a physical change c) This is both a physical and chemical change d) Physical and chemical changes cannot occur simultaneously 8) Which of the following reactions corresponds to the electron affinity for bromine? a) Br (g) + e - Br - (g) b) Br (g) Br + (g) + e - c) Br - (g) Br (g) + e - d) Br + (g) + 2 e - Br - (g) 9) Based on data in the table below, calculate the value of equilibrium constant for the following reaction. N 2 O 4 (g) 2 NO 2 (g) Experiment Initial [N 2 O 4 ] (M) Initial [NO 2 ] (M) Equilibrium Equilibrium [N 2 O 4 ] (M) [NO 2 ] (M) 1 0.0 0.0200 0.00140 0.0172 2 0.0 0.0300 0.00280 0.0243 a) 0.211 b) 12.3 c) 0.115 d) 8.68 10) Yttrium forms +3 cation. Which one of the following is a likely formula for its salts? a) Y 3 I 2 b) Y 2 S 3 c) YBr d) Y 3 PO 4 11) What is the ph of an aqueous solution at 25.0 C in which [OH - ] is 0.0025 M? a) 2.60 b) -2.60 c) 11.40 d) 1.60 12) Which bond in the molecule shown below is sp hybridized? a) Bond 1 b) Bond 3 c) Bond 4 d) Bond 5 Page 2 of 7
13) What is the net ionic equation for the reaction of aqueous Co(NO 3 ) 2 with aqueous Na 2 S? a) Co(NO 3 ) 2 (aq) + Na 2 S (aq) CoS (s) + 2 NaNO 3 (aq) b) Co 2+ (aq) + S 2- (aq) CoS (s) c) Na + (aq) + NO - 3 (aq) NaNO 3 (aq) d) Co 2+ (aq) + 2 Na + (aq) + 2 NO - 3 (aq) + S 2- (aq) CoS (s) + 2 Na + (aq) + 2 NO - 3 (aq) 14) What is the frequency (s -1 ) of a photon of yellow-orange light with wavelength 589 nm? a) 1.12 x 10-27 b) 5.09 c) 1.77 x 10 2 d) 5.09 x 10 14 15) What is the ground state electronic configuration for bromine? a) 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5 b) 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 4p 5 c) 1s 2 2s 2 2p 6 3s 2 3p 5 d) 1s 2 2s 2 2p 6 3s 2 3p 5 3d 10 16) Which of the following groups are not isotopes? a) b) c) d) 17) A student wants to measure the density of a metal rod. He transfers 11.25 ml of water into a graduated cylinder. He gently drops the rod in the cylinder and the water level rises to 14.25 ml. If the weight of the rod is 5.1230 g, calculate the density (in g/ml). a) 1.71 b) 0.360 c) 15.4 d) 0.586 18) On a cold winter s day up north a student on his school break at his parents is enjoying the outdoor hot tub. He looks at the steam rising from the tub and the snow as far as he can see. How many phases of water is he witnessing? a) 1 b) 2 c) 3 d) 4 Page 3 of 7
19) An inflated balloon has a volume of 5.0 L at sea level (1.0 atm) and is allowed to ascend in altitude until the pressure is 0.35 atm. During ascent the temperature of the gas falls from 22 C to 21 C. Calculate the volume of the balloon at its final altitude. a) 4.3 L b) 12 L c) 14 L d) 17 L 20) The molecular geometry of the CHCl 3 molecule is, and the molecule is. a) trigonal pyramidal, polar b) tetrahedral, nonpolar c) seesaw, nonpolar d) tetrahedral, polar 21) Calculate the mass percent of sulfur in aluminum sulfate. a) 28% b) 43% c) 96% d) Cannot be calculated since the total mass of the sample is not given 22) The gas pressure in an aerosol can is 2.0 atm at 25 C. Assuming that the gas inside obeys the ideal-gas equation, what would the pressure be if the can were heated to 450 C? a) 3.6 atm b) 8.2 atm c) 4.9 atm d) 4.5 atm 23) Which of the following formula/name pairs is correct? a) Mn 2 O 7 is Manganese (VIII) oxide b) Fe 2 S is Iron (II) sulfide c) FePO 4 is Iron (III) phosphite d) CuSO 4 is copper (II) sulfate Page 4 of 7
24) A pill contains 50 mg of active ingredient, 3.5 g flour and 500 mg sugar. The percent by mass of the active ingredient is: a) 1% b) 9% c) 20% d) Percent active ingredient cannot be calculated 25) Which of the following reactions is/are oxidation-reduction reaction(s)? a) AgNO 3 (aq) + CaCl 2 (aq) AgCl (s) + Ca(NO 3 ) 2 (aq) b) KOH (aq) + H 2 SO 4 (aq) K 2 SO 4 (aq) + 2 H 2 O (l) c) O 2 (aq) + N 2 H 4 (aq) 2 H 2 O (l) + N 2 (g) d) All of the above are oxidation reduction reactions 26) Which of the following sets of atoms is correctly ranked according to increasing atomic size? a) C < Ge < S < Po b) C < S < Ge < Po c) Po < Ge < C < S d) Ge < Po < S < C 27) Compare the numbers 3400 and 34.0 for significant figures: a) Both numbers have the same number of significant figures b) 3400 has more significant figures than 34.0 c) The product of 34.0 multiplied by 3400 will contain the same number of significant figures as in 34.0 d) If we place a decimal point after 34 in 3400 it will have the same number of significant figures as the 34.0 Page 5 of 7
23) Consider the phase diagram for a substance (Figure below). Which statement is FALSE? a) A B represents solid-vapor equilibrium. b) A D represents solid-liquid equilibrium. c) A represents the triple point d) C represents the melting point 29) The Millikan oil drop experiment: a) Determined the charge of an electron b) Calculated the new mass for the electrons to be twice that of a proton c) Confirmed Bohr s theory about the orbitals of hydrogen d) Culminated in Millikan becoming known as the father of modern chemistry 30) A mixture of iron filings and sulfur powder is a. a) homogenous mixture b) heterogeneous mixture c) solution of a metal and a non-metal d) compound Page 6 of 7
Constants Equations R = 8.314 J mol -1 K -1 ln k = - + ln A = kt + R = 0.0821 L atm mol -1 K - 1 1 F = 96,500 J V -1 mol -1 t 1/2 = [A] t = -kt + [A] 0 N A = 6.022 x 10 23 mol -1 h = 6.626 x 10-34 J s t 1/2 = Rate = k[a] m [B] n c = 2.998 x 10 8 m s -1 0 C = 273.15 K ln[a] t ln[a] 0 = -kt k = Ae -Ea/RT Page 7 of 7
FGCU Invitational Chemistry: Useful Equations and Constants Constants Equations R = 8.314 J mol -1 K -1 ln k = - + ln A = kt + R = 0.0821 L atm mol -1 K -1 1 F = 96,500 J V -1 mol -1 N A = 6.022 x 10 23 mol -1 t 1/2 = [A] t = -kt + [A] 0 h = 6.626 x 10-34 J s c = 2.998 x 10 8 m s -1 t 1/2 = Rate = k[a] m [B] n 0 C = 273.15 K ln[a] t ln[a] 0 = -kt k = Ae -Ea/RT