Chem 1120 final exm
For which of the following entries does the molecule labeled A not have the higher boiling point? (i) A. HOCH2CH2OH or B. CH3CH2CH2CH2OH (ii) A. Cl2 or B. SO2 (iii) A. KCl or B. ClBr (iv) A. NH3 or B. Ar (v) A. ClF or B. Cl2 Select one: (i) (ii) (iii) (iv) (v)
(ii)
Determine the value of ∆G˚ (in kJ/mol) for the following reaction using data from the table below. 2H2O (g) + O2 (g) -> 2H2O2 (g) Substance ∆Gf˚ (kJ/mol) H2O (g) -228 H2O2 (g) -105 Select one: +246 -246 -666 +666 None of these
+246
What is the oxidation number of Cl in HClO3? Select one: +5 +7 +4 +3 none of the above
+5
Consider the following product-favored reaction occurring in an automobile engine (C8H18 is gasoline) The signs for ΔH, ΔS, and ΔG would be: 2 C8H18(l) + 25 O2(g) -> 16 CO2(g) = 18 H2O(g) Select one: -, +, + +, -, - -, -, - +, +, - -, +, -
-, +, -
The volume of an ideal gas is zero at ______. Select one: -273 K -363 K -45 °F -273 °C 0 °C
-273 °C
Calculate Gibbs free energy for the following reaction. Mg (s) + Pb2+(aq) -> Mg2+(aq) + Pb(s) Eocell = +2.24 V Select one: +216 kJ/mol None of these +423 kJ/mol -423 kJ/mol -216 kJ/mol
-423 kJ/mol
The equilibrium constant at 25oC for the reaction 2NO(g)+O2(g) -> 2NO2(g) is Kp = 1.65 x 10^12. Calculate Delta G for the reaction at this temp Select one -4.09 kJ/mol 1.65 kJ/mol 5.85 kJ/mol -69.7 kJ/mol -5.85 kJ/mol
-69.7 kJ/mol
Ethyl chloride, C2H5Cl was used to make leaded gasoline back in the "good old days". C2H5Cl decomposes (via first order kinetics) upon heating to yield ethene, C2H4 and HCl.C2H5Cl -> C2H4 + HClThis process has a measured half-life of 772 seconds at 350 °C. Suppose 0.451 M C2H5Cl is placed in a container and allowed to decompose at 350 °C. What is the concentration of C2H5Cl after 55.0 minutes? Select one: 0.0233 M 0.429 M 0.0855 M 0.421 M 0.415 M
0.0233 M
A solution of fructose, C6H12O6 (molar mass = 180.16), a sugar found in many fruits, is made by dissolving 24.0 g of fructose in 1 kg of water. If the density of this solution is 1.0078 g/mL, what is the molarity of the fructose solution? Select one: 5.84 M 0.521 M 0.584 M 10.0 M 0.131 M
0.131 M
Which aqueous solution should have the highest boiling point? Select one: 0.100 molar CaCl2 0.150 molar Ba(NO3)2 0.100 molar Al(NO3)3 0.200 molar NH3 0.150 molar NaCl Feedback
0.150 molar Ba(NO3)2
Consider the reaction between nitrogen dioxide and carbon monoxide: NO2(g) + CO(g) -> NO(g) + CO2(g) The initial rate of the reaction is measured at several different concentrations of the reactants with the results show below: From this data the rate law was determined to be: Rate = k[NO2]2. What is the value of k? Select one: 0.82 M-1s-1 0.21 M-1s-1 2.1 x 10-5 M-1s-1 476.2 M2s 30.3 s-1
0.21 M-1s-1
The value of ΔG° for a reaction conducted at 25 °C is 3.05 kJ/mol. The equilibrium constant for a reaction is ________ at this temperature. Select one: -4.20 0.292 More information is needed 0.320 -1.13 Feedback
0.292
Nitrogen gas is easy to generate by numerous different chemical reactions. Suppose you generate some N2 (g) and collect the gas over water into a 753 mL flask at 50.0 °C. The barometric pressure during the experiment was 651.1 mm Hg. How many grams of N2 (g) are in the container? (The vapor pressure of water is 92.51 torr at 50.0)°C. Select one: 259 0.681 0.780 518 0.584
0.584
A sample of a gas (5.0 mol) at 1.0 atm is expanded at constant temperature from 10 L to 15 L. The final pressure is ______ atm. Select one: 1.5 7.5 0.67 3.3 15
0.67
The solubility of PbI2 (Ksp = 9.8 x 10-9) varies with the composition of the solvent in which it was dissolved. In which solvent mixture would PbI2 have the lowest solubility at identical temperatures? Select one: 1.0 M HCl(aq) pure water 1.5 M KI(aq) 0.8 M MgI2(aq) 1.0 M Pb(NO3)2(aq)
0.8 M MgI2(aq)
For the following, in which case would the buffer capacity not be exhausted either by the addition of 0.5 moles of HCl or by the addition of 0.5 moles of NaOH? Select one: 0.10 M HF and 0.60 M NaF 0.80 M HF and 0.90 M NaF 0.80 M HF and 0.20 M NaF 0.10 M HF and 0.20 M NaF None of these
0.80 M HF and 0.90 M NaF
The barometric pressure in a cavern was measured using a mercury barometer. A value of 74.2 cm of Hg was obtained. How many atmospheres is this? Select one: 9.76 atm 1.024 atm 0.0976 atm 0.976 atm 5.64 atm
0.976 atm
A generic reaction was studied and the rate data obtained is tabulated below. A + Y -> B + C Determine the order with respect to [Y]. Select one: 0 2 2.37 1 3
1
Which of the following statements are true. 1. catalysts speed up the rate of a reaction without themselves being consumed2. a plot of ln[concentration] vs. time produces a straight line for overall first order reactions3. a plot of ln[concentration] vs. time produces a straight line for overall second order reactions4. the activation energy, Ea, is obtained by a graph of ln[concentration] vs. time (in seconds) Select one: 1 and 2 1, 2, 4 1, 3, 4 3 and 4 1, 2, 3 Feedback
1 and 2
Of the following species below, which ones are STRONG acids?1. HNO3 2. CH3COOH 3. HF 4. H2SO4 5. HNO2 Select one: 1, 3 and 4 2 and 5 1 and 3 4 and 5 1 and 5 1 and 4 3 and 4 2 and 3 1, 3, and 5 2, 3 and 4
1 and 4
This balanced reaction is known to achieve equilibrium: PCl3 (g) + Cl2 (g) ⇌ PCl5 (g) Visualize four separate containers. Each container is initially charged as follows:Container 1: PCl3 and PCl5 Container 2: PCl3Container 3: PCl3 and Cl2 Container 4: PCl5 Equilibrium, as given in the above reaction, can be established in which containers? Select one: only 3 2, 3, and 4 1 and 2 1 and 3 only 4 3 and 4 1, 2, 3, and 4 1 and 4 1, 3 and 4 1, 2, and 3
1,3,4
Which of the following statements are true. 1. as temperature increases, the rate of a reaction typically increases2. the rate constant, k, varies with reactant concentration3. the rate constant, k, varies with temperature4. the units for the rate constant, k, is always 1/time for overall first order reactions Select one: 1 and 3 1, 2, 3 2 and 3 1 and 2 1, 3, 4
1,3,4
Which statements below are true: 1. the average kinetic energy of gas particles is proportional to temperature 2. the average kinetic energy of gas particles is inversely proportional to temperature 3. gas particles are in continuous motion with varying velocities 4. a gas with a smaller molecular weight (MW) will diffuse faster than one with a larger MW 5. a gas with a larger molecular weight (MW) will diffuse faster than one with a smaller MW Select one: 2, 3, 4 1, 3, 4 1, 3, 5 2, 5 2, 3, 5
1,3,4
Which one of the following cannot act as a buffer solution? Select one: 0.20 M NH3 and 0.25 M NH4Cl 0.50 M HCN and 0.10 NaCN 0.40 M HNO2 and 0.10 NaNO2 0.10 M HC2H3O2 and 0.10 M NaC2H3O2 1.0 M KCl and 1.0 M HCl
1.0 M KCl and 1.0 M HCl
How many grams of lead(II) chloride would dissolve in 100 mL of water? The Ksp for lead(II) chloride is 2.4 x 10-4 and the molar mass is 278.1 g/mol. Select one: 1.1 g 1.4 x 10-4 g 4.3 g 0.039 g 10.9 g
1.1 g
Given the following information: H2 (g) + C2H4 (g) ⇌ C2H6 (g) Kc = 9.4 x 1013 (at some temp) What is the numerical value of the equilibrium constant, Kc for the reverse reaction above at the same temperature. C2H6 (g) ⇌ H2 (g) + C2H4 (g) Kc = ? Select one: -1.1 x 10-14 1.1 x 10-14 -9.4 x 10-13 9.4 x 1013 -1.1 x 1014 -9.4 x 1013 9.4 x 10-12 1.1 x 1014 9.4 x 10-13
1.1 x 10-14
An aqueous solution, made by dissolving 168 mg of an unknown compound (a nonelectrolyte) in enough water to make 500.0 mL of solution, develops an osmotic pressure of 5.22 torr at a temperature of 23.5°C. What is the molecular mass of this unknown compound? Select one: 94.3 g mol-1 943 g mol-1 124 g mol-1 1.57 x 103 g mol-1 1.19 x 103 g mol-1
1.19 x 103 g mol-1
Balance the reaction and determine Eo for the following unbalanced reaction. Al + Co2+ -> Al3+ + Co ΔGo = -799 kJ Select one: +2.55 V +0.490 V +1.38 V None of these +0.275 V
1.38 V
If the OH‑ ion concentration in an aqueous solution at 25.0o C is 6.6 x 10‑4 M, what is the molarity of the H+ ion? Select one: 6.6 x 10‑10 M 1.5 x 10‑1 M 1.5 x 10‑4 M 6.6 x 10‑11 M 1.5 x 10-11 M Feedback
1.5 x 10-11 M
What is the pH of a 1.00 molar solution of nitrous acid? HONO (aq) ⇌ H+ (aq) + ONO- (aq) Ka = 7.1 x 10-4 Select one: 1.93 2.04 2.67 3.15 1.57
1.57
What is the solubility, in moles per liter, of AgCl (Ksp = 1.8 × 10‑10) in 0.0100 molar aqueous potassium chloride solution? Select one: 1.3 × 10‑6 mol L-1 7.5 × 10‑5 mol L-1 3.6 × 10‑8 mol L-1 1.5 × 10‑7 mol L-1 1.8 × 10‑8 mol L-1
1.8 × 10‑8 mol L-1
Calculate the value of Eo for the reaction shown, given the standard reduction potentials: Reduction Potentials Br2 -> 2Br- Eo = +1.08 V Zn2+ -> Zn Eo = -0.76V Overall Reaction Zn + Br2 -> ZnBr2 Eo = ? Select one: -0.38 V 1.84 V +0.38 V None of these 0.68 V
1.84 V
An aqueous solution of glycerol, C3H8O3 (92.09 g/mol), is 48.0% glycerol by mass and has a density of 1.120 g mL-1. Calculate the molality of the glycerol solution. Select one: 0.131 m 10.0 m 5.84 m 0.584 m 0.521 m
10.0 m
A solution is 30.5% by mass of antifreeze (C2H6O2, MW = 62.07) in water. For this solution calculate the the boiling point. Select one: 96.38oC 103.62oC 102.52oC 97.48oC 101.86oC
103.62oC
Imagine that you live in a small cabin deep in the woods. The interior volume of the cabin is 475 m3 (that's cubic meters). On a cold morning in February, the indoor temperature of the cabin is 2.3 °C, and the barometric pressure is 0.933 atm. By afternoon the sun has warmed the cabin to a balmy 24.5 °C and the barometric pressure is 747 mm Hg. The cabin is not air tight, so some air obviously "leaks" out of the cabin. How many cubic meters, m3, of air has been forced out of the cabin at these afternoon conditions? Select one: 463 m3 487 m3 474 m3 12 m3 0.64m3
12 m3
Given the following solutions: 0.20 M NaOH(aq) 0.20 M HCl(aq) A mixture is made using 50.0 mL of the NaOH solution and 25.0 mL of the HCl solution. What is its pH at 25.0 °C? Select one: 12.52 13.30 12.82 13.00 7.00
12.82
What is the value for ∆H˚ for this reaction at 25˚C? C(s) + H2O (g) -> CO (g) + H2 (g) ∆G˚ = +91.2 kJ/mol; ∆S˚ = 135 J/K. mol Select one: 91 kJ/mol 40321 kJ/mol 226 kJ/mol 40 kJ/mol 131 kJ/mol
131 kJ/mol
17.8 g of iron(II) sulfate is dissolved into 75.5 g of water. Determine the mass percentage of the aqueous iron(II) sulfate in the solution. Select one: 1.55% 19.1% 23.6% 4.24% 80.9%
19.1%
A generic reaction was studied and the rate data obtained is tabulated below. A + Y -> B + C Determine the reaction order with respect to [A]. Select one: 2.37 0 3 2 1
2
After balancing the following redox reaction, what is the coefficient for H2O? H2CrO4 + Fe -> Cr2O3 + Fe2O3 + H2O Select one: 8 5 1 2 None of these
2
Which statements below are true: 1. as altitude increases, atmospheric pressure increases. 2. as altitude increases, atmospheric pressure decreases. 3. the volume of a gas is directly proportional to temperature (assuming constant P and n). 4. the volume of a gas is inversely proportional to temperature (assuming constant P and n). 5. 1 mole of gas will occupy 22.4 L at STP. Select one: 2 and 3 2, 3, and 5 4 and 5 2, 4, and 5 1 and 3
2,3,5
The Ka of hydrocyanic acid (HCN) is 4.9 x 10-10. What is the Kb of CN-? Select one: 9.1 x 10-10 4.9 x 104 4.9 x 10-10 2.0 x 10-5 9.3
2.0 x 10-5
Given the following reduction potentials, what would be the Eo for a cell for a product-favored reaction involving the chemicals shown? Cl2 + 2 e- -> 2 Cl- Eo = +1.32 V Cr3+ + 3 e- -> Cr Eo = -0.74 V Select one: 4.9 V 1.72 V 0.58 V None of these 2.1 V
2.1 V
The reaction 2NO (g) + 2H2 (g) -> N2 (g) + 2H2O (g) was found to follow the rate law, rate = k[NO]2[H2]. By what factor will the rate of reaction increase when the pressure of NO gas is increased from 2.0 M to 3.0 M? Assume all other conditions are held constant Select one: 3 2 1 1.5 2.25
2.25
A vessel contains a mixture of 34.9 grams of H2 (g) and 17.7 grams of CH4. If the total pressure inside the vessel is measured at 2.92 atm, the partial pressure of H2 (g) must be _____ atm. Select one: 2.75 5.53 50.5 53.8 0.175
2.75
A solution is prepared by dissolving 40.0 g of sucrose, C12H22O11 (MW = 342.30), in 250. g of water at 25°C. What is the vapor pressure of the solution if the vapor pressure of water at 25°C is 23.76 mm Hg? Select one: 23.6 mm Hg 24.0 mm Hg 0.008 mm Hg 0.198 mm Hg 20.5 mm Hg
23.6 mm Hg
Some bacteria have the ability to decompose simple sugars into methane, CH4 and carbon dioxide, CO2. How many liters of methane will be produced by the decomposition of 555 g of glucose, C6H12O6 (s) at 41 °C and 668.0 mm Hg ? The MW of C6H12O6 (s) is 180.16 g/mole. C6H12O6 (s) -> 3 CH4 (g) + 3 CO2 (g) (it's balanced) Select one: 30.1 210 90.4 25.0 271
271
An exothermic reaction generates KBr(g) according to the following equation: K(g) + Br2(g) -> KBr(g) + Br(g) If the energy of activation of this reaction is + 12.7 kJ/mol, what is the energy of activation (in kJ/mol) for the reverse reaction? Select one: 33.7 8.0 -33.4 -8.0 33.4 Feedback
33.4
A gas sample weighing 3.78 grams occupies a volume of 2.28 L at STP. What is the molar mass of the sample in g/mol? Select one: 37.1 51.1 8.54 13.5 193 Feedback
37.1
If the concentration of a reactant is 6.25%, how many half-lives has it gone through? Select one: 10 4 7 3 5
4
The solubility product for PbBr2 is: Ksp = 6.6 × 10‑6. Which of the following represents the solubility of PbBr2? Select one: 4.3 g/L 4.7 × 10-1 g/L 2.4 × 10-3 g/L 6.1 × 10-4 g/L 6.0 × 10-4 g/L Feedback
4.3 g/L
The solubility of scandium(III) fluoride, ScF3, in pure water is 2.0 × 10‑5 moles per liter. Calculate the value of Ksp for scandium(III) fluoride from this data. Select one: 1.6 × 10‑19 1.3 × 10‑17 4.8 × 10‑19 4.3 × 10‑18 1.4 × 10‑18
4.3 × 10‑18
Calculate the pH of a beer in which the hydrogen ion concentration is 3.9 x 10-5 M. Select one: 9.6 10.1 5. 3.9 4.4
4.4
A buffer solution is prepared by taking 0.400 moles of acetic acid (pKa = 4.76) and 0.250 moles of sodium acetate in sufficient water to make 1.400 liters of solution. Calculate the pH of this solution. Select one: 4.66 4.86 4.56 4.96 4.46
4.56
2.50 kilograms of wastewater from a cement factory was analyzed and found to contain 1.24 g of Mg2+(aq). What is the ppm (parts per million) concentration of Mg2+(aq) in the wastewater? Select one: 2016 4.96 x 105 0.496 496 0.0411 Feedback
496
Nitrosyl chloride, NOCl (g), decomposes to NO (g) and Cl2 (g). Suppose a container is initially charged with 3.4 M NOCl and then allowed to decompose to NO (g) and Cl2 (g) until equilibrium is established. At equilibrium, the [Cl2] = 0.23 M. What is the numerical value for Kc for this reaction at this temperature ? The reaction is indeed balanced. 2 NOCl (g) ⇌ 2 NO (g) + Cl2 (g) Select one: 1.0 x 10-2 6.7 x 10-2 4.2 5.6 x 10-3 1.8 x 102
5.6 x 10-3
How many grams of Zn metal (65.4 g/mol) will be produced by passing a current of 6.6 amps through a solution of ZnI2 for 45 minutes? Select one: 6.6 g 6.0 g None of these 3.3 g 0.111 g Feedback
6.0 g
Glutamic acid, HC5H8NO4 is a weak acid. A 0.298 M HC5H8NO4 (aq) solution of glutamic acid has a pH = 1.40. What is the Ka of glutamic acid? Select one: 4.0 x 10-2 2.1 x 10-2 5.2 x 10-3 1.6 x 10-3 6.1 x 10-3
6.1 x 10-3
Determine the value of Kp for the balanced reaction below at equilibrium. 3 NO (g) ⇌ N2O (g) + NO2 (g) Kc = 2.7 x 105 (at 225 °C) Select one: 6.6 x 103 1.4 x 102 5.0 x 106 2.7 x 105 5.4 x 10-2
6.6 x 103
The pH at the equivalence point of the titration of a nitric acid solution by sodium hydroxide is Select one: > 11.0 < 2.00 7.00 7.00 < pH < 11.00 4.00 < pH < 7.00
7.00
What is the pH of a 1.00 molar solution of KCl (assume 25oC)? Select one: 7.00 13.00 6.90 7.10 0.00
7.00
How much energy (in kJ) is required to vaporize 98.6 g of ethanol (C2H5OH) at its boiling point, if its ΔHvap is 40.5 kJ/mol? Select one: 11.5 86.7 52.8 39.9 18.9
86.7
Consider the equilibrium reaction of elemental carbon and carbon dioxide to produce carbon monoxide. Choose the correct answer for each question below. C (s) + CO2 (g) ⇌ CO (g) How will the reaction respond to an increase in temperature? A. Reaction will shift to the right B. Reaction will shift to the left C. No effect D. Can't tell
A
Consider the equilibrium reaction of elemental carbon and carbon dioxide to produce carbon monoxide. Choose the correct answer for each question below. C (s) + CO2 (g) ⇌ CO (g) How will the reaction respond to the removal of C (s)? A. Reaction will shift to the right B. Reaction will shift to the left C. No effect D. Can't tell
A
Which of the following is TRUE? Select one: A neutral solution contains [H2O] = [H3O+] A basic solution does not contain H3O+ An acidic solution has [H3O+] > [OH⁻] None of these statements is true. A neutral solution does not contain any H3O+ or OH⁻
An acidic solution has [H3O+] > [OH⁻]
Consider the equilibrium reaction of elemental carbon and carbon dioxide to produce carbon monoxide. Choose the correct answer for each question below. C (s) + CO2 (g) ⇌ CO (g) How will the reaction respond to an increase in pressure? A. Reaction will shift to the right B. Reaction will shift to the left C. No effect D. Can't tell
B
Consider the equilibrium reaction of elemental carbon and carbon dioxide to produce carbon monoxide. Choose the correct answer for each question below. C (s) + CO2 (g) ⇌ CO (g) How will the reaction respond to the addition of CO (g)? A. Reaction will shift to the right B. Reaction will shift to the left C. No effect D. Can't tell
B
Given the following substances and their normal boiling points, in °C: C: 43.8°C D: 93.7°C M: 56.7°C T: 83.5°C R: 63.6°C Which ranking correctly lists some of these liquids in order of decreasing intermolecular forces at 20°C? A: C > R > D B: D > R > M c: D > C > R D: C > D > M E: R > T > D
B: D>R>M
Which one of the following salts has the highest solubility in water, expressed in moles per liter? Select one: Ag2CrO4, Ksp = 1.2 × 10‑12 BaF2, Ksp = 1.7 × 10‑6 PbI2, Ksp = 7.9 × 10‑9 PbF2, Ksp = 3.6 × 10‑8 CaF2, Ksp = 3.9 × 10‑11
BaF2, Ksp = 1.7 × 10‑6
Consider the equilibrium reaction of elemental carbon and carbon dioxide to produce carbon monoxide. Choose the correct answer for each question below. C (s) + CO2 (g) ⇌ CO (g) How will the reaction respond to the addition of a catalyst? A. Reaction will shift to the right B. Reaction will shift to the left C. No effect D. Can't tell
C
What compound will not exhibit hydrogen bonding in the liquid state? Select one: CH3-NH-CH3 CH3-CH2-CH2-OH NH2-OH CH3-CH2-NH2 CH3-CH2-Br Feedback
CH3-CH2-Br
Which compound should have the highest vapor pressure at a temperature at which all these substances are in the liquid state? Select one: CH3-CH2-S-H CH3-CH2-CH2-CH3 CH3-O-CH3 CH3-CH2-CH3 CH3-CH3
CH3-CH3
Consider a solution prepared by adding 0.50 moles of CH3COONa (sodium acetate) to 1.00 L of 1.00M CH3COOH (acetic acid, Ka = 1.8 x 10-5). If 0.050 moles of HCl is added to this buffer solution, the pH of the solution will drop slightly. The pH does not drastically decrease because the HCl reacts with the ______ present in the buffer solution. Select one: None of these CH3COONa H2O H+ CH3COOH
CH3COONa
Of the following gases, ________ will have the greatest rate of effusion at a given temperature. Select one: Ar NH3 HCl HBr CH4
CH4
Which reaction is accompanied by an increase in entropy? Select one: N2(g) + 3 H2(g) -> 2 NH3(g) Na2CO3(s) + CO2(g) + H2O(g) -> 2 NaHCO3(s) ZnS(s) + 3/2 O2(g) -> ZnO(s) + SO2(g) BaO(s) + CO2(g) -> BaCO3(s) CH4(g) + H2O(g) -> CO(g) + 3H2(g)
CH4(g) + H2O(g) -> CO(g) + 3H2(g)
Arrange the following gases in order of increasing average molecular speed at 25 °C. He, O2, CO2, N2 Select one: He < O2 < N2 < CO2 He < N2 < O2 < CO2 CO2 < He < N2 < O2 CO2 < O2 < N2 < He CO2 < N2 < O2 < He
CO2 < O2 < N2 < He
Which solid would be more soluble in a strong acid solution than in pure water? Select one: LiNO3 CaCO3 AgBr MgBr2 NaCl Feedback
CaCO3
Which species is being oxidized in the galvanic cell composed of these two half cells, with the standard potentials shown? Co2+(aq) + 2 e‑ -> Co(s) ‑0.28 volt Cd2+(aq) + 2 e‑ -> Cd(s) ‑0.40 volt Select one: Cd2+ Co2+ Cd Co
Cd
Which statement about chemical equilibrium is not true? Select one: At equilibrium, the forward reaction rate equals the reverse reaction rate. Chemical equilibrium can only be attained by starting with reagents from the reactant side of the equation. The same equilibrium state can be attained starting either from the reactant or product side of the equation. At equilibrium, the reactant and the product concentrations show no further change with time. At equilibrium, the reactant and product concentrations are constant.
Chemical equilibrium can only be attained by starting with reagents from the reactant side of the equation.
Which set below has the species listed in order of increasing standard entropy, S°? Select one: Cr(s) < NaHCO3(aq) < C2H5OH(l) < N2(g) Cr(s) < N2(g) < NaHCO3(aq) < C2H5OH(l) Cr(s) < C2H5OH(l) < NaHCO3(aq) < N2(g) NaHCO3(aq) < C2H5OH(l) < Cr(s) < N2(g) N2(g) < NaHCO3(aq) < Cr(s) < C2H5OH(l)
Cr(s) < C2H5OH(l) < NaHCO3(aq) < N2(g)
Which substance is the oxidizing agent in the following reaction? 3Mg + 2FeBr3 -> 3MgBr2 + 2 Fe Select one: Fe None of these FeBr3 Mg MgBr2
FeBr3
Which transformation could take place at the anode of an electrochemical cell? Select one: H2SO4 to H2S2O3 None of these H2O to O2 Mn2+ to Mn Br2 to Br-
H2O to O2
Which species is the strongest acid? Select one: NH3 H2O H2Te H2S H2Se
H2Te
Which of the following acids will have the strongest conjugate base? Select one: HCN HClO4 H2SO4 HCl HNO3
HCN
Of the following, which is the weakest acid? Select one: HIO HIO2 HIO3 HIO4 All of these acids have the same strength
HIO
Which substance has greatest amount of viscosity at 25 °C? Select one: HOCH2CH2CH2OH (l) CH3CH2CH2CH2CH2CH3 (l) CH3CH2CH2CH2OH (l) Feedback
HOCH2CH2CH2OH (l)
Which substance has largest surface tension at 25 °C? Select one: CH3CH2CH2CH2OH (l) CH3CH2CH2CH2CH2CH3 (l) HOCH2CH2CH2OH (l)
HOCH2CH2CH2OH (l)
Which of the following species is amphoteric (can serve as an acid or a base)? Select one: NH4+ CO32- None of these are amphoteric HF HPO42-
HPO42-
Which one of the following statements is true about the equilibrium constant for a reaction if ΔG° for the reaction is negative? Select one: K=0 K>1 K=1 K<1 More information needed
K>1
Consider the following balanced reaction. What is the equilibrium expression, Kc, that describes the reaction. I2 (s) + 5 F2 (g) ⇌ 2 IF5 (g)
Kc = [IFe]2/[F2]5
Which of the following is the expression for the solubility product of Ca3(PO4)2? Select one: Ksp= [3 x Ca2+]3 × [2 x PO43‑]2 Ksp=3[Ca2+] × 2[PO43‑] Ksp= [Ca2+]3 × [PO43‑]2 Ksp=3[Ca2+]3 + 2[PO43‑]2 Ksp= [Ca2+]3 × [PO43‑]2
Ksp= [Ca2+]3 × [PO43‑]2
For small molecules of comparable molecular weight, which one of the following choices lists the intermolecular forces in the order of increasing strength? Select one: hydrogen bonds < dipole-dipole forces < London dispersion forces dipole-dipole forces < hydrogen bonds < London dispersion forces London dispersion forces < hydrogen bonds < dipole-dipole forces hydrogen bonds < London dispersion forces < dipole-dipole forces London dispersion forces < dipole-dipole forces < hydrogen bonds
London dispersion forces < dipole-dipole forces < hydrogen bonds
A reaction is determined to have the rate law, Rate = k [B]2. What are the units of k? Select one: M-1s-1 M-2s-1 s-1 M-3s-1 M-4s-1
M-1s-1
Which of the following is the best sacrificial electrode for iron? Select one: Au Cu Pb Ni Mg
Mg
Which of the following species would be suitable for a salt bridge in a galvanic cell? Select one: H2O C6H6 C12H22O11 NaNO3 AgCl
NaNO3
Given the following reduction potentials, which species would react with Cu2+? Select one: None of these Cd and Al only Br- only Ni, Cd and Al Cd2+ and Al3+ only
Ni, Cd and Al
Given 0.01 M solutions of each of the following acids, which solution would have the lowest pH? Select one: Nitrous acid (HNO2), pKa = 3.34 Hydrofluoric acid (HF), pKa = 3.46 Phenol (HC6H5O), pKa = 9.89 Acetic acid (HC2H3O2), pKa = 4.74 Formic acid (HCHO2), pKa = 3.74
Nitrous acid (HNO2), pKa = 3.34
Consider this reaction: F2 (g) + Cl2 (g) ⇌ ClF3 (g) Kp = 58 (at some temp) A sample from a reaction vessel running the above reaction is analyzed and the partial pressures (or pp) of each species are found to be: pp F2 = 0.16 atm; pp Cl2 = 0.29 atm; and pp ClF3 = 0.33 atm. Which answer below best describes the situation occurring inside the reaction vessel? Select one: Q = 6.7 and the reaction will shift to the Left to attempt to establish equilibrium Q = 6.7 and the reaction will shift to the Right to attempt to establish equilibrium Q = 92 and the reaction will shift to the Right to attempt to establish equilibrium Q = 92 and the reaction will shift to the Left to attempt to establish equilibrium Q = 58 and equilibrium is established and will remain as is unless disturbed by some outside force
Q = 92 and the reaction will shift to the Left to attempt to establish equilibrium
In which of the following reactions will Kc = Kp? Select one: 2 SO2(g) + O2(g) ⇌ 2 SO3(g) 4 NH3(g) + 3 O2(g) ⇌ 2 N2(g) + 6 H2O(g) None of the reactions have Kp = Kc 2 N2(g) + O2(g) ⇌ 2 N2O(g) SO3(g) + NO(g) ⇌ SO2(g) + NO2(g)
SO3(g) + NO(g) ⇌ SO2(g) + NO2(g)
Molten PbCl2 is subjected to electrolysis in order to form elemental lead and chlorine. Which of the following is false? Select one: Electrons flow from the anode to the cathode None of these Elemental lead metal is formed and deposited at the cathode. Elemental chlorine gas is formed at the cathode and bubbles away.
The correct answer is: Elemental chlorine gas is formed at the cathode and bubbles away.
A real gas behaves most nearly like an ideal gas under conditions of Select one: high temperature and low pressure low temperature and high pressure low temperature and low pressure STP high temperature and high pressure
The correct answer is: high temperature and low pressure
Which of the following is a condition that must be met for a gas to be considered as "ideal"? Select one: The gas sample must not contain water vapor. The gas must contain carbon The gas must have a small molar mass. The gas molecules must have no intermolecular attractive forces between themselves. The gas sample must be enclosed in a large container. Feedback
The gas molecules must have no intermolecular attractive forces between themselves.
The scattering of light by a collodial dispersion is known as: Select one: Tyndall effect. an emulsion. an aerosol. Brownian motion. micellar repulsion.
Tyndall effect.
Which of the following statements is TRUE? Select one: Vapor pressure increases with temperature. None of these statements are true. Dispersion forces are generally stronger than dipole-dipole forces. Intermolecular forces hold the atoms in molecules together. Hydrogen bonds are stronger than covalent bonds.
Vapor pressure increases with temperature.
When a nonvolatile solute such as ammonium sulfate is dissolved in a solvent like water, one of the observed effects is: Select one: an increase in the freezing point of the liquid. a decrease in the vapor pressure of the solvent. scattering of light beams by the solute particles in the solution. a decrease in the boiling point of the liquid. an increase in the vapor pressure of the solute.
a decrease in the vapor pressure of the solvent.
Which of the following is not one of the five factors mentioned in the text that can affect the rate at which a reaction proceeds? Select one: concentration of reactants catalysts all of these temperature the ability of reactants to come into contact with each other Feedback
all of these
Which statements about viscosity are true? (i) Viscosity increases as temperature decreases. (ii) Viscosity increases as molecular weight increases. (iii) Viscosity increases as intermolecular forces increase. Select one: (i) only (i) and (iii) (ii) and (iii) none of these statements is true all of these statements are true
all of these statements are true
The critical temperature of a substance is Select one: the temperature below which the substance cannot be supercooled. the temperature below which the substance cannot be liquefied by increasing the pressure. always higher than the triple point temperature. the temperature below which the substance cannot exist in the liquid state. the temperature which is always higher than the Kelvin point.
always higher than the triple point temperature.
Consider the following information and given equilibrium constant for the balanced reaction. H2 (g) + C2H4 (g) ⇌ C2H6 (g) Kc = 9.4 x 1013 (at some temp) What is the physical meaning of the equilibrium constant, Kc for the above reaction? Select one: at equilibrium, the container will have slightly more products and slightly less reactants at equilibrium, the container will have slightly more reactants and slightly less products at equilibrium, the container will have roughly the same amount of reactants and products at equilibrium, the container will have mostly reactants and very little products at equilibrium, the container will have mostly products and very little reactants
at equilibrium, the container will have mostly products and very little reactants
Which of the following will always cause an increase in the solubility of a gas in a solvent (in which the gas does not react with the solvent) to form a new substance? Select one: increasing the temperature of the solvent while maintaining the pressure of the gas in the space above the solvent at a set value. decreasing the temperature of the solvent and simultaneously increasing the pressure of the gas in the space above the solvent. decreasing the temperature of the solvent and simultaneously decreasing the pressure of the gas in the space above the solvent. increasing the temperature of the solvent and simultaneously increasing the pressure of the gas in the space above the solvent. increasing the temperature of the solvent and simultaneously decreasing the pressure of the gas in the space above the solvent.
decreasing the temperature of the solvent and simultaneously increasing the pressure of the gas in the space above the solvent.
Wax is a solid mixture of hydrocarbon compounds consisting of molecules with long chains of carbon atoms. Which solvent would you expect to be most capable of dissolving wax? Select one: c a d e b
e
The thermodynamic quantity that expresses the extent of randomness in a system is ________. Select one: internal energy enthalpy heat flow bond energy entropy
entropy
Heat of sublimation can be approximated by adding together ________ and ________. Select one: heat of fusion, heat of condensation heat of freezing (solidification), heat of condensation heat of freezing (solidification), heat of vaporization heat of deposition, heat of vaporization heat of fusion, heat of vaporization
heat of fusion, heat of vaporization
Fluids used for an intravenous transfusion must be ________ with bodily fluids. Select one: hypertonic platonic isotonic neotonic hypotonic
isotonic
The rate of a chemical reaction in solution can be measured in the units: Select one: s‑2 sec L‑1 mol‑1 L2 mol‑1 s‑1 mol s L‑1 mol L‑1 s‑1
mol L‑1 s‑1
Determine the pH of a 0.371 M aqueous solution of the base aziridine, C2H4NH (aq). The pKb of aziridine is 5.95. Select one: pH = 11.06 pH = 10.81 pH = 3.19 pH = 7.61 pH = 13.57
pH = 10.81
What is the pH of a 0.027 M KOH (aq) solution at 25 °C? Select one: pH = 13.95 pH = 12.43 pH = 11.30 pH = 10.39 pH = 1.57
pH = 12.43
Consider the Haber process for the production of NH3. At a certain instance in time, the concentration of H2 is decreasing at a rate of 0.024 M/sec. At this same time, what is the rate that NH3 is increasing? N2 + 3 H2 -> 2 NH3 Select one: 0.0080 M/sec 0.016 M/sec 0.072 M/sec 0.024 M/sec 0.036 M/sec
rate of appearance of NH3 = 2/3(0.024 M/sec) = 0.016 M/sec 0.016 M/sec
The strongest intermolecular attractive forces exist between particles of a ________, and the weakest intermolecular attractive forces exist between particles of a ________. Select one: solid, gas solid, liquid gas, solid liquid, solid liquid, gas
solid, gas
Is the following reaction spontaneous and what is its standard cell potential? 2H2O2(aq) + S(s) → SO2(g) + 2H2O H2O2(aq) + 2H+(aq) + 2e - → 2H2O E ° = +1.77 V SO2(g) + 4H+(aq) +4e - → S(s) + 2H2O E ° = +0.45 V Select one: spontaneous; +1.32 V spontaneous; +2.22 V non-spontaneous; -1.32 V None of these spontaneous; +3.09 V
spontaneous; +1.32 V
Given the phase changes: condensation, freezing, fusion, sublimation, vaporization. Which (set) of these phase changes is (are) endothermic? Select one: fusion and vaporization only sublimation, fusion, and vaporization only fusion only fusion and sublimation only condensation and freezing only Feedback
sublimation, fusion, and vaporization only
NH3 can react with BF3, forming NH3-BF3. In this reaction, Select one: NH3 acts as a Brønsted base, accepting a proton from the BF3 molecule. the BF3 molecule acts as a Lewis base, donating an electron pair to the NH3 molecule to form a coordinate covalent bond. NH3 acts as a Lewis base, donating a proton to the BF3 molecule. NH3 acts as a Brønsted acid, donating a proton to the BF3 molecule. the BF3 molecule acts as a Lewis acid, accepting an electron pair from the NH3 molecule to form a coordinate covalent bond.
the BF3 molecule acts as a Lewis acid, accepting an electron pair from the NH3 molecule to form a coordinate covalent bond.
If container "A" is occupied by 1.00 mole of nitrogen gas while container "B" is occupied by 20.0 grams of oxygen gas and both containers are maintained at 0.00oC and 650 torr then, Select one: container "B" must be larger than container "A". container "A" must have a volume of 22.4 L. the number of atoms in container "B" is greater than the number of atoms in container "A". the average speed of the molecules in container "B" is less than that of the molecules in container "A". the average kinetic energy of the molecules in "A" is equal to the average kinetic energy of the molecules in "B".
the average kinetic energy of the molecules in "A" is equal to the average kinetic energy of the molecules in "B".
A negative sign for ΔG indicates that, at constant temperature and pressure, Select one: the reaction is spontaneous. the reaction must be exothermic. the reaction must be endothermic. the reaction must be fast. ΔS must be greater than zero.
the reaction is spontaneous.
For a certain chemical reaction, ΔH is < 0 and ΔS is < 0. This means that Select one: we conclude the reaction must be spontaneous regardless of temperature and becomes even more so at higher temperatures. we conclude the reaction may or may not be spontaneous, but spontaneity is favored by high temperatures. we cannot make any conclusion about spontaneity or even tendencies from the limited information presented. we conclude the reaction must be spontaneous regardless of temperature and becomes even more so at lower temperatures. we conclude the reaction may or may not be spontaneous, but spontaneity is favored by low temperatures.
we conclude the reaction may or may not be spontaneous, but spontaneity is favored by low temperatures.
A reaction that is spontaneous as written __________. Select one: is very rapid. has an equilibrium position that lies far to the left. is also spontaneous in the reverse direction. will proceed without outside intervention. exhibits all of these listed traits.
will proceed without outside intervention.