Chemistry Final Exam Study Problems
Which one of the following is a Bronsted-Lowry base? A. (CH3)3N B. CH3COOH C. HF D. HNO2
(CH3)3N
43. A .1 M solution of _________ has a pH of 7.0?
LiCLO4
An aqueous solution of ________ will produce a neutral solution. A. LiNO3 B. NaNO2 C. KF D. Rb2CO3 E. NH4NO3
LiNO3
How can we measure pH?
Litmus paper, indicator, pH meter
The overall order of a reaction is 2. The units of the rate constant for the reaction are ________.
M-1 s-1
Which of these metals will be oxidized by the ions of aluminum? A. magnesium B. zinc C. chromium D. iron E. nickel
Magnesium
The purpose of the salt bridge in an electrochemical cell is to __________
Maintain electrical neutrality in the half cells via migration of ions
The reaction between strontium hydroxide and chloric acid produces ________.
a molecular compound and a strong electrolyte
An aqueous solution of ________ will produce a basic solution. A. sodium sulfite B. rubidium bromide C. magnesium perchlorate D. ammonium nitrate E. potassium nitrate
sodium sulfite
Is osmotic pressure net movement of solute or solvent?
solvent
An ideal gas differs from a real gas in that the molecules of an ideal gas
Have no attraction for one another
45. What would happen to the height of a mercury column in a barometer as the altitude increases?
Height would decrease
Which behaves more like an ideal gas, helium or chlorine?
Helium
Alpha Particle
Helium nucleus
What makes a hydrogen bond?
Hydrogen bound to a F, O, N that can bind to another hydrogen bound to an F, O, N
Phase changes are not associated with temperature increases because the heat energy is used up to
Increase distance between molecules
26. The effect of a catalyst on an equilibrium is to
Increase the rate at which equilibrium is achieved without changing the composition of the equilibrium mixture
A reaction was found to be second order in carbon monoxide concentration. The rate of reaction ___________ if the [CO] is doubled with everything else kept the same.
Increased by a factor of 4
How does viscosity change as the IMFs become stronger?
Increases
20. What are never included in rate laws?
Intermediates
Hydrophobic colloids can be stabilized in solution by:
Ions burying a nonpolar region in the hydrophobic colloid and leaving a charged region on the surface to interact with water AND adsorption of ions onto the surface
Which of the following is most likely not a gas at room temperature? A. KBr B. F2 C. HCN D. SO2 E. CH4
KBr
A 1.35 m aqueous solution of compound X had a boiling point of 101.4 °C. Which one of the following could be compound X? The boiling point elevation constant for water is 0.52 °C/m. A. CH3CH2OH B. C6H12O6 C. Na3PO4 D. KCl E. CaCl2
KCl
The amount of gas that occupies 60.82 L at 31.0 °C and 367 mm Hg is ________ mol.
1.18
The pH of a solution prepared by mixing 40.0 mL of 0.125 M Mg(OH)2 and 150.0 mL of 0.125 M HCl is ________.
1.34
Using the van der Waals equation, the pressure in a 22.4 L vessel containing 1.00 mol of neon gas at 100 degrees C is ________ atm. (a = 0.211 L2-atm/mol2, b = 0.0171 L/mol)
1.37
The following reaction is second order in [A] and the rate constant is 0.025 M-1s-1: A → B The concentration of A was 0.65 M at 33 s. The initial concentration of A was ________ M.
1.4
Calculate the concentration (in M) of hydronium ions in a solution at 25.0 °C with a pOH of 4.223.
1.67 x 10^-10
The Ka of hydrofluoric acid (HF) at 25.0 °C is 6.8 × 10^-4. What is the pH of a 0.45 M aqueous solution of HF?
1.76
Acetic acid is a weak acid that dissociates into the acetate ion and a proton in aqueous solution: HC2H3O2 (aq) <---> C2H3O2- (aq) + H+ (aq) At equilibrium at 25 °C a 0.100 M solution of acetic acid has the following concentrations: [HC2H3O2] = 0.0990 M, [C2H3O2-] = 1.33 × 10-3 M and [H+] = 1.33 × 10-3 M. The equilibrium constant, Keq, for the ionization of acetic acid at 25 °C is ________.
1.79 x 10^-5
Sodium bicarbonate is reacted with concentrated hydrochloric acid at 37.0 °C and 1.00 atm. The reaction of 6.00 kg of bicarbonate with excess hydrochloric acid under these conditions will produce ________ L of CO2.
1.82 x 10^3
A reaction vessel is charged with hydrogen iodide, which partially decomposes to molecular hydrogen and iodine: 2HI (g) <---> H2(g) + I2(g) When the system comes to equilibrium at 425 °C, PHI = 0.708 atm, and PH2 = PI2 = 0.0960 atm. The value of Kp at this temperature is ________.
1.84 x 10^-2
Gallium crystallizes in a primitive cubic unit cell. The length of the unit cell edge is 3.70 Å. The radius of a Ga atom is ________ Å.
1.85
A solution is prepared by dissolving 2.60 g of a strong electrolyte (formula weight = 101 g/mol) in enough water to make 1.00 L of solution. The osmotic pressure of the solution is 1.25 atm at 25.0 °C. What is the van't Hoff factor (i) for the unknown solute?
1.98
The enthalpy change for converting 1.00 mol of ice at -25.0 °C to water at 50.0 °C is ________ kJ. The specific heats of ice, water, and steam are 2.09 J/g-K, 4.18 J/g-K, and 1.84 J/g-K, respectively. For H2O, ΔHfus = 6.01 kJ/mol, and ΔHvap = 40.67 kJ/mol.
10.71
A 25.0 mL sample of 0.150 M hydrazoic acid is titrated with a 0.150 M NaOH solution. What is the pH after 26.0 mL of base is added? The Ka of hydrazoic acid is 1.9 × 10^-5.
11.47
A sealed 1.0 L flask is charged with 0.500 mol of I2 and 0.500 mol of Br2. An equilibrium reaction ensues: I2 (g) + Br2 (g) <---> 2IBr (g) When the container contents achieve equilibrium, the flask contains 0.84 mol of IBr. The value of Keq is ________.
110
The pH of a solution prepared by mixing 50.0 mL of 0.125 M NaOH and 40.0 mL of 0.125 M HNO3 is ________.
12.14
A 1.0 × 10^-2 M aqueous solution of Ca(OH)2 at 25.0 °C has a pH of ________.
12.30
Five solution pH values are listed below. Which solution has the highest concentration of hydroxide ions? A. 12.5 B. 11 C. 8.3 D. 6.0 E. 3.0
12.5
An aqueous solution contains 0.100 M NaOH at 25.0 °C. The pH of the solution is ________.
13.00
A balloon originally had a volume of 4.39 L at 44 °C and a pressure of 729 torr. The balloon must be cooled to ________ °C to reduce its volume to 3.99 L (at constant pressure).
15.1
30.0 grams of argon and 15.0 grams of xenon are placed in a 170.9 ml container at 21.8 °C. The partial pressure of xenon is ________ atm.
16.1
Given the following reaction: CO (g) + 2 H2(g) <---> CH3OH (g) In an experiment, 0.42 mol of CO and 0.42 mol of H2 were placed in a 1.00-L reaction vessel. At equilibrium, there were 0.29 mol of CO remaining. Keq at the temperature of the experiment is ________.
17.5
At 200 °C, the equilibrium constant (Kp) for the reaction below is 2.40 × 10^3. 2NO (g) <---> N2 (g) + O2 (g) A closed vessel is charged with 36.1 atm of NO. At equilibrium, the partial pressure of O2 is ________ atm.
17.9
A tank containing both HF and HBr gases developed a leak. The ratio of the rate of effusion of HF to the rate of effusion of HBr is ________.
2.01
The acid-dissociation constant, Ka, for gallic acid is 4.57 × 10^-3. What is the base-dissociation constant, Kb, for the gallate ion?
2.19 x 10^-12
Potassium metal crystallizes in a body-centered cubic structure with a unit cell edge length of 5.31 Å. The radius of a potassium atom is ________ Å.
2.30
SO2 (5.00 g) and CO2 (5.00 g) are placed in a 750.0 mL container at 50.0 °C. The partial pressure of SO2 in the container was ________ atm.
2.76
At 24° C, Kp = 0.080 for the equilibrium: NH4HS (s) <---> NH3 (g) + H2S (g) A sample of solid NH4HS is placed in a closed vessel and allowed to equilibrate. Calculate the equilibrium partial pressure (atm) of ammonia, assuming that some solid NH4HS remains.
2.8
The pH of an aqueous solution at 25.0 °C is 10.55. What is the molarity of H+ in this solution?
2.8 x 10^-11
Consider the following reaction: 3A → 2B The average rate of appearance of B is given by Δ[B]/Δt. Comparing the rate of appearance of B and the rate of disappearance of A, we get Δ[B]/Δt = ________ × (-Δ[A]/Δt).
2/3
The vapor pressure of pure water at 25 °C is 23.8 torr. Determine the vapor pressure (torr) of water at 25 °C above a solution prepared by dissolving 25 g of urea (a nonvolatile, non-electrolyte, MW = 60.0 g/mol) in 75 g of water.
22
Standard volume of gases:
22.4 L
A vessel contained N2, Ar, He, and Ne. The total pressure in the vessel was 987 torr. The partial pressures of nitrogen, argon, and helium were 44.0, 486, and 218 torr, respectively. The partial pressure of neon in the vessel was ________ torr.
239
If 50.75 g of a gas occupies 10.0 L at STP, 129.3 g of the gas will occupy ________ L at STP.
25.5
Standard temperature of gases:
273.15 K or 0C
A sample of oxygen gas (O2) was found to effuse at a rate equal to three times that of an unknown gas. The molecular weight of the unknown gas is ________ g/mol.
288
How many milliliters of 0.0839 M NaOH are required to titrate 25.0 mL of 0.0990 M HBr to the equivalence point?
29.5
A 25.0 mL sample of 0.723 M HClO4 is titrated with a 0.27 M KOH solution. The H3O+ concentration after the addition of 80.0 mL of KOH is ________ M.
3 x 10^-13
The rate constant of a first-order process that has a half-life of 3.50 min is ________ s-1.
3.3 x 10^-3
A particular first-order reaction has a rate constant of 1.35 × 10^2 1/s at 25.0 °C. What is the magnitude of k at 75.0 °C if Ea = 55.3 kJ/mol?
3.34 x 10^3
A sample of He gas (3.0 L) at 5.6 atm and 25 °C was combined with 4.5 L of Ne gas at 3.6 atm and 25 °C at constant temperature in a 9.0 L flask. The total pressure in the flask was ________ atm. Assume the initial pressure in the flask was 0.00 atm and the temperature upon mixing was 25 °C.
3.7
Calculate the pH of a solution that is 0.278 M in sodium formate (NaHCO2) and 0.222 M in formic acid (HCO2H). The Ka of formic acid is 1.77 × 10^-4.
3.84
A pressure of 0.500 atm is the same as a pressure of ________ of mm Hg.
380
Calculate the pH of a solution prepared by dissolving 0.150 mol of benzoic acid and 0.300 mol of sodium benzoate in water sufficient to yield 1.00 L of solution. The Ka of benzoic acid is 6.30 × 10^-5.
4.50
The Ka of hypochlorous acid (HClO) is 3.00 × 10^-8. What is the pH at 25.0 °C of an aqueous solution that is 0.0200 M in HClO?
4.61
How many milliliters of 0.120 M NaOH are required to titrate 50.0 mL of 0.0998 M hypochlorous acid to the equivalence point? The Ka of hypochlorous acid is 3.0 × 10^-8.
41.6
A 25.0-mL sample of 0.150 M hydrocyanic acid is titrated with a 0.150 M NaOH solution. What is the pH before any base is added? The Ka of hydrocyanic acid is 4.9 × 10^-10.
5.07
Kp = 0.0198 at 721 K for the reaction 2HI (g) <---> H2 (g) + I2 (g) In a particular experiment, the partial pressures of H2 and I2 at equilibrium are 0.678 and 0.788 atm, respectively. The partial pressure of HI is ________ atm.
5.19
A sample of O2 gas (2.0 mmol) effused through a pinhole in 5.0 s. It will take ________ s for the same amount of CO2 to effuse under the same conditions.
5.9
Ethanol (C2H5OH) melts at -114 °C. The enthalpy of fusion is 5.02 kJ/mol. The specific heats of solid and liquid ethanol are 0.97 J/g-K and 2.3 J/g-K, respectively. How much heat (kJ) is needed to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -60 °C?
6.34
HZ is a weak acid. An aqueous solution of HZ is prepared by dissolving 0.020 mol of HZ in sufficient water to yield 1.0 L of solution. The pH of the solution was 4.93 at 25.0 °C. The Ka of HZ is ________.
6.9 x 10^-9
The pH of a solution prepared by mixing 50.0 mL of 0.125 M KOH and 50.0 mL of 0.125 M HCl is ________.
7.00
The half-life of a first-order reaction is 13 min. If the initial concentration of reactant is 0.085 M, it takes ________ min for it to decrease to 0.055 M.
8.2
What is the pH of an aqueous solution at 25.0 °C that contains 3.98 × 10^-9 M hydronium ion?
8.40
A 25.0 mL sample of 0.150 M benzoic acid is titrated with a 0.150 M NaOH solution. What is the pH at the equivalence point? The Ka of benzoic acid is 6.25 × 10^-5.
8.54
An unknown metal is arranged in a lattice of face-centered cubic unit cells. The density is 2.64 g/cm3, and the atomic radius is 0.215 nm. What is the atomic weight in g/mol?
89.4
A sample of He gas (2.35 mol) occupies 57.9 L at 300.0 K and 1.00 atm. The volume of this sample is ________ L at 469 K and 1.00 atm.
90.5
The temperature of a sample of CH4 gas (10.34 g) in a 50.0 L vessel at 1.33 atm is ________ °C.
984
What must a Bronsted Lowry base have?
A pair of nonbonding electrons to accept the proton
42. A 0.0035 M aqueous solution has a pH of 2.46. The compound is
A strong acid
39. CH3- is the conjugate base of CH4. CH4 shows no evidence of being an acid in water. How would you characterize CH3-?
A strong base
44. What happens to our blood pH when we hold our breath?
Becomes more acidic
A possible mechanism for the overall reaction Br2 (g) + 2NO (g) → 2NOBr (g) is NO (g) + Br2 (g) <---> NOBr2 (g) (fast, equilibrium) NOBr2 (g) + NO (g) → 2NOBr (slow) The rate law for formation of NOBr based on this mechanism is rate =
(k2 k1/k-1) [NO]^2 [Br2]
35. For a reaction to be spontaneous under standard conditions at all temperatures, the signs of ΔH and ΔS must be ________ and _________ respectively
-, +
The value of ΔG° at 25 °C for the following reaction: C2H4 (g) + H2 (g) → C2H6 (g) is ________ kJ/mol. At 298 K, ΔH° for this reaction is -137.5 kJ/mol, and ΔS° is +120.5 J/K.
-173.4
What is the freezing point (°C) of a solution prepared by dissolving 11.3 g of Ca(NO3)2 (formula weight = 164 g/mol) in 115 g of water? The molal freezing point depression constant for water is 1.86 °C/m.
-3.34
Phosphorous and chlorine gases combine to produce phosphorous trichloride: P2 (g) + 3Cl2 (g) → 2PCl3 (g) ΔG° at 298 K for this reaction is -642.9 kJ/mol. The value of ΔG at 298 K for a reaction mixture that consists of 1.9 atm P2, 1.6 atm Cl2, and 0.65 atm PCl3 is ________.
-650.1
A 50.0 mL sample of an aqueous H2SO4 solution is titrated with a 0.375 M NaOH solution. The equivalence point is reached with 62.5 mL of the base. The concentration of H2SO4 is ________ M.
.234
Nitrosyl bromide decomposes according to the following equation. 2NOBr (g) <---> 2NO (g) + Br2 (g) A sample of NOBr (0.64 mol) was placed in a 1.00-L flask containing no NO or Br2. At equilibrium the flask contained 0.16 mol of NOBr. How many moles of NO and Br2, respectively, are in the flask at equilibrium?
.48 and .24
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.
.67
STP is _____________ oC and ________ atm.
0, 1
What is the osmotic pressure of a solution formed by dissolving 45.0 mg of aspirin (C9H8O4) in 0.250 L of water at 25 °C? All answers in units of atm.
0.0245
A 25.0 mL sample of an acetic acid solution is titrated with a 0.175 M NaOH solution. The equivalence point is reached when 10.2 mL of the base is added. What was the concentration of acetic acid in the sample? The Ka of acetic acid is 1.77 × 10^-5.
0.0714
At elevated temperatures, methylisonitrile (CH3NC) isomerizes to acetonitrile (CH3CN): CH3NC (g) → CH3CN (g) At the start of an experiment, there are 0.200 mol of reactant and 0 mol of product in the reaction vessel. After 25 min, 0.121 mol of reactant (CH3NC) remain. There are ________ mol of product (CH3CN) in the reaction vessel.
0.079
The rate of disappearance of HBr in the gas phase reaction 2HBr (g) → H2 (g) + Br2 (g) is 0.190 M s-1 at 150 °C. The rate of appearance of Br2 is ________ M s-1.
0.095
Which solution will be the most basic? A. 0.10 M Ba(OH)2 B. 0.10 M KOH C. 0.10 M H2O D. 0.10 M CH3OH E. All solutions have equal basicity.
0.10 M Ba(OH)2
The Ka of hypochlorous acid (HClO) is 3.0 × 10^-8 at 25 °C. What is the percent ionization of hypochlorous acid in a 0.015 M aqueous solution of HClO at 25 °C?
0.14
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.
0.292
The pressure of a sample of CH4 gas (6.022 g) in a 30.0 L vessel at 402 K is ________ atm.
0.413
In a gas mixture of He, Ne, and Ar with a total pressure of 8.40 atm, the mole fraction of Ar is ________ if the partial pressures of He and Ne are 1.50 and 2.00 atm, respectively.
0.583
An aqueous solution contains 0.150 M HCl at 25.0 °C. The pH of the solution is ________
0.82
Dinitrogentetraoxide partially decomposes according to the following equilibrium: N2O4 (g) <---> 2 NO2 (g) A 1.00-L flask is charged with 0.0400 mol of N2O4. At equilibrium at 373 K, 0.0055 mol of N2O4 remains. Keq for this reaction is ________.
0.87
What is the osmotic pressure of a 0.040 M solution of a non-electrolyte at 30.0 °C?
1.0 atm
The molar concentration of hydroxide ion in pure water at 298 K is:
1.0 x 10^-7
Crystalline solids differ from amorphous solids in that crystalline solids have
A long range repeating pattern of atoms, molecules, or ions
41. The conjugate base of a strong acid is
A negligible base
The concentration of CO2 in a soft drink bottled with a partial pressure of CO2 of 4.0 atm over the liquid at 25 °C is 1.2 × 10-1 M. The Henry's law constant for CO2 at this temperature is ________.
A. 3.0 × 10-2 mol/L-atm
Which of the following is an oxidation-reduction reaction? A. Cu (s) + 2AgNO3 (aq) → 2Ag (s) + Cu(NO3)2 (aq) B. HCl (aq) + NaOH (aq) → H2O (l) + NaCl (aq) C. AgNO3 (aq) + HCl (aq) → AgCl (s) + HNO3 (aq) D. Ba(C2H3O2)2 (aq) + Na2SO4 (aq) → BaSO4 (s) + 2NaC2H3O2(aq) E. H2CO3 (aq) + Ca(NO3)2 (aq) → 2HNO3 (aq) + CaCO3 (s)
A. Cu (s) + 2AgNO3 (aq) → 2Ag (s) + Cu(NO3)2 (aq)
What can stop a gamma particle?
Almost nothing
40. In water, most weak acids exist
As mostly molecular acids with some dissociated ions
Consider the following equilibrium. 2 SO2 (g) + O2 (g) <---> 2 SO3 (g) The equilibrium cannot be established when ________ is/are placed in a 1.0-L container. A. 0.25 mol SO2 (g) and 0.25 mol O2 (g) B. 0.75 mol SO2 (g) C. 0.25 mol of SO2 (g) and 0.25 mol of SO3 (g) D. 0.50 mol O2 (g) and 0.50 mol SO3 (g) E. 1.0 mol SO3 (g)
B. 0.75 mol SO2 (g)
Of the following solutions, which has the greatest buffering capacity? A. 0.521 M HC2H3O2 and 0.217 M NaC2H3O2 B. 0.821 M HC2H3O2 and 0.713 M NaC2H3O2 C. 0.365 M HC2H3O2 and 0.497 M NaC2H3O2 D. 0.121 M HC2H3O2 and 0.116 M NaC2H3O2
B. 0.821 M HC2H3O2 and 0.713 M NaC2H3O2
ΔS is positive for the reaction ________. A. 2NO (g) + O2 (g) → 2NO2 (g) B. C3H8 (g) + 5 O2 (g) → 3CO2 (g) + 4 H2O (g) C. 2N2 (g) + 3H2 (g) → 2NH3 (g) D. Mg (s) + Cl2 (g) → MgCl2 (s) E. C2H4 (g) + H2 (g) → C2H6 (g)
B. C3H8 (g) + 5 O2 (g) → 3CO2 (g) + 4 H2O (g)
Which reaction produces a decrease in the entropy of the system? A. 4 NH3 (g) + 5 O2 (g) → 4 NO (g) + 6 H2O (g) B. Na (s) + 1/2 Cl2 (g) → NaCl (s) C. 2 HgO (s) → 2 Hg (l) + O2 (g) D. UF6 (s) → U (s) + 3F2 (g) E. H2O (s) → H2O (g)
B. Na (s) + 1/2 Cl2 (g) → NaCl (s)
Of the following, ________ is a valid statement of Charles' law. A. P/T = constant B. V/T = constant C. PV = constant D. nV = constant E. P = V x constant
B. V/T = constant
Consider the following reaction at equilibrium: 2NH3 (g) <---> N2 (g) + 3H2 (g) Le Châtelier's principle predicts that the moles of H2 in the reaction container will increase with ________. A. some removal of NH3 from the reaction vessel (V and T constant) B. a decrease in the total pressure (T constant) C. addition of some N2 to the reaction vessel (V and T constant) D. a decrease in the total volume of the reaction vessel (T constant) E. an increase in total pressure by the addition of helium gas (V and T constant)
B. a decrease in the total pressure (T constant)
One significant difference between gases and liquids is: A. a gas is made up of molecules B. a gas expands to fill its container C. a gas may consist of both elements and compounds D. gases are always mixtures E. all of the above
B. a gas expands to fill its container
"Like dissolves like" means:
B. polar solvents dissolve polar solutes and nonpolar solvents dissolve nonpolar solutes
List the 6 strong bases:
Ba(OH)2 KOH NaOH Sr(OH)2 Ca(OH)2 LiOH
Which of the following molecules has hydrogen bonding as the strongest IMF present? A. CH4 B. CH3CN (acetonitrile) C. CH3CH2OH D. NaCl E. CH3F
C. CH3CH2OH
Which one of the following statements is true about the equilibrium constant for a reaction if ΔG° for the reaction is negative? A. K = 0 B. K = 1 C. K > 1 D. K < 1
C. K > 1
Which statement about atmospheric pressure is false? A. as air becomes thinner, its density decreases B. air actually has weight C. air pressure increases as altitude increases D. the warmer the air, the lower the atmospheric pressure E. atmospheric pressure prevents the water in lakes and oceans from boiling away
C. air pressure increases as altitude increases
Consider the following reaction at equilibrium: 2CO2 (g) <---> 2CO (g) + O2 (g) ΔH° = -514 kJ Le Châtelier's principle predicts that an increase in temperature will ________. A. increase the partial pressure of O2 (g) B. decrease the partial pressure of CO2 (g) C. decrease the value of the equilibrium constant D. increase the value of the equilibrium constant E. increase the partial pressure of CO
C. decrease the value of the equilibrium constant
Which one of the following substances is more likely to dissolve in CCl4? A. CBr4 B. HBr C. HCl D. CH3CH2OH E. NaCl
CBr4
Which of the following choices has the compounds correctly arranged in order of increasing solubility in water? (least soluble to most soluble) CH4 < NaNO3 < CHCl3 LiF < NaNO3 < CHCl3 CH3OH < CH4 < LiF CCl4 < CHCl3 < NaNO3 CH3OH < CCl4 < CHCl3
CCl4 < CHCl3 < NaNO3
Order the following compounds by their predicted boiling point, from lowest to highest. (CH3)2NH, CH3NH2, CF4, CH3F
CF4, CH3F, (CH3)2NH, CH3NH2
Of the following gases, ________ will have the greatest rate of effusion at a given temperature. A. NH3 B. CH4 C. Ar D. HBr E. HCl
CH4
Which of the following molecules has London dispersion forces as the strongest IMF present? A. CH3CN (acetonitrile) B. CH3F C. CH4 D. NaCl E. CH3CH2OH
CH4
A mixture of carbon dioxide and an unknown gas was allowed to effuse from a container. The carbon dioxide took 1.25 times as long to escape as the unknown gas. Which one could be the unknown gas? A. Cl2 B. CO C. HCl D. H2 E. SO2
CO
22. Which one of the following will change the value of an equilibrium constant?
Changing temperature
Catalysts speed up reactions by
Changing the reaction mechanism
Which of the following ions will act as a weak base in water? A. OH- B. Cl- C. NO3- D. ClO- E. None of the above will act as a weak base.
ClO-
Integrated rate laws are used to relate what?
Concentration of reactants and time
32. The entropy of the universe is
Continually increasing
Which is stronger, IMFs or covalent bonds?
Covalent bonds because they involve the sharing of valence electrons
A gas reacts with a solid that is in one large lump. In a second experiment the solid is crushed. Which reaction will have a faster rate?
Crushed solid
Which melts at a specific temperature, crystalline or amorphous solids?
Crystalline solids
The mechanism for formation of the product X is: A + B → C + D (slow) B + D → X (fast) What is the intermediate in the reaction?
D
Which of the following are weak acids? A. HF, HBr B. HI, HNO3, HBR C. HI, HF D. HF
HF
At 400 K, the equilibrium constant for the reaction Br2 (g) + Cl2 (g) <---> 2BrCl (g) is Kp = 7.0. A closed vessel at 400 K is charged with 1.00 atm of Br2 (g), 1.00 atm of Cl2 (g), and 2.00 atm of BrCl (g). Which statement below is true? A. The equilibrium partial pressures of Br2, Cl2, and BrCl will be the same as the initial values. B. The equilibrium partial pressure of Br2 will be greater than 1.00 atm. C. At equilibrium, the total pressure in the vessel will be less than the initial total pressure. D. The equilibrium partial pressure of BrCl (g) will be greater than 2.00 atm. E. The reaction will go to completion since there are equal amounts of Br2 and Cl2.
D. The equilibrium partial pressure of BrCl (g) will be greater than 2.00 atm.
In a saturated solution of a salt in water: A. the rate of crystallization > the rate of dissolution B. the rate of dissolution > the rate of crystallization C. seed crystal addition may cause massive crystallization D. the rate of crystallization = the rate of dissolution E. addition of more water causes massive crystallization
D. the rate of crystallization = the rate of dissolution
How does viscosity change as temperature increases?
Decreases
37. What is a characteristic of a Bronsted Lowry base?
Has a nonbonding pair of electrons
Which of the following liquids will have the lowest freezing point? A. pure water B. aqueous 0.60 m glucose C. aqueous 0.60 m sucrose D. aqueous 0.24 m ferric iodide E. aqueous 0.50 m potassium fluoride
E. aqueous 0.50 m potassium fluoride
Is the melting of ice exothermic or endothermic?
Endothermic
For a very dilute aqueous solution, is the molarity greater than, less than, or equal to the molality?
Equal
Which of the following molecules contain London dispersion forces? A. H2O B. CH3Br C. CO2 D. NaCl in water E. All of the above contain London dispersion forces.
Everything has LDFs
Which of the following has hydrogen bonding as its ONLY intermolecular force? A. NH3 B. H2O C. C3H7OH D. CH4 E. none of the above
Everything will have LDFs
Which kind of cubic unit cell has the greatest packing efficiency?
Face centered
29. If a process is nonspontaneous, that means that the process cannot occur under any conditions, true or false?
False
T/F: An intermediate is the same thing as the transition state.
False
T/F: At constant temperature, reducing the volume of a gaseous equilibrium mixture causes the reaction to shift in the direction that increases the number of moles of gas in the system.
False
True of False: Pure water will conduct electricity?
False
True or false An intermediate in a reaction is the same thing as a transition state?
False
T/F: The effect of a catalyst on a chemical reaction is to react with product, effectively removing it and shifting the equilibrium to the right.
False; catalysts have no effect on the equilibrium
T/F: The quantity of energy gained by a system equals the quantity of energy gained by its surroundings.
False; one is greater
T/F: The entropy of a pure crystalline substance at 0C is zero
False; should be 0K
Pressure has an appreciable effect on the solubility of ________ in liquids
Gases
The net ionic equation for the reaction between aqueous sulfuric acid and aqueous sodium hydroxide is ________.
H+ (aq) + OH- (aq) → H2O( l)
The balanced molecular equation for complete neutralization of H2SO4 by KOH in aqueous solution is ________.
H2SO4 (aq) + 2KOH (aq) → 2H2O (l) + K2SO4 (aq)
List the 7 strong acids:
HCl HNO3 HClO4 HClO3 H2SO4 HI HBR
What are three types of pH indicators?
Methyl red Bromthymol blue Phenolphthalein
Which compound has the atom with the highest oxidation number? A. CaS B. Na3N C. MgSO3 D. Al(NO2)3 E. NH4Cl
MgSO3
What is the conjugate acid of NH3?
NH4+
An aqueous solution of ________ will produce an acidic solution. A. NH4I B. KBr C. Sr(ClO4)2 D. K2CO3 E. NaNO3
NH4I
The volume of a sample of gas (2.49 g) was 752 mL at 1.98 atm and 62 °C. The gas is ________. A. SO2 B. SO3 C. NH3 D. NO2 E. Ne
NO2
Which gas will effuse faster, neon or xenon?
Neon
Which molecule is moving faster at 298K, neon or xenon?
Neon
In the following reaction, which species is reduced? Au(s) + 3NO3-(aq) + 6H+(aq) → Au3+(aq) + NO(g) + 3H2O (l)
Nitrogen
Are hydrogen bonds the same as covalent bonds?
No
Can sodium chloride dissolve in hexane?
No
18. Does a catalyst increase reaction rate by the same means as a rise in temperature does?
No, they act in different ways.
A solution containing which one of the following pairs of substances will be a buffer solution? A. KI, HI B. AgBr, HBr C. CuCl, HCl D. CsI, HI E. none of the above
None
What units are associated with K and Q?
None
Which hydroxides are weak bases? A. KOH B. Ba(OH)2 C. RbOH D. CsOH E. None
None
31. The reverse of a spontaneous process is
Nonspontaneous
Which substance in the reaction below either appears or disappears the fastest? 4NH3 + 7O2 → 4NO2 + 6H2O
O2
Use can use stoichiometry to predict the rate law ONLY when and WHY
You know that the reaction is elementary because rate law is governed by elementary steps, not their sum
Why does H2O form hydrogen bonds, but not H2Se?
Oxygen is both smaller and electronegative than selenium, so hydrogen is attracted to the long pair more strongly in H2O as opposed to H2Se
How is the partial pressure of one gas changed by the addition of another gas into the system?
Partial pressure does not change
The ease with which the charge distribution of the electron cloud in a molecule can be distorted by an external electrical field is called the
Polarizability
Which will affect colligative properties more, adding 1 mole of potassium chloride to water, or adding 1 mole of glucose to the same amount of water?
Potassium chloride
36. What is a Bronsted Lowry acid?
Proton donor
34. If the entropy of a system is zero, what do you know about the system?
Pure, crystalline solid at 0 K
As the temperature of a reaction is increased, the rate of the reaction increases because the
Reactant molecules collide more frequently and with greater energy per collision
A reaction is carried out with water as a solvent. More water is added to the reaction vessel. What happens to the reaction rate.
Reaction slows down
Does the thing being oxidized or reduced gain mass?
Reduced
30. What kinds of motion could a molecule undergo that a single atom cannot?
Rotational and vibrational
We never include ________ in reaction quotient or equilibrium expressions.
Solids and liquids
Which of the following statements is true? A. Processes that are spontaneous in one direction are spontaneous in the opposite direction. B. Processes are spontaneous because they occur at an observable rate. C. Spontaneity can depend on the temperature. D. All of the above statements are true.
Spontaneity can depend on the temperature
21. The equilibrium constant expression depends on the _________ of the reaction
Stoichiometry
27. In equilibrium problems, we need to use ____________ to find the relationship between the change in reactants and products
Stoichiometry
What factor does not necessarily affect reaction rate?
Stoichiometry of the overall reaction
In general, the vapor pressure of a substance increases as _____ increases
Temperature
k in a rate law varies with what?
Temperature
33. What can we conclude about the entropy change of the surroundings?
The entropy change of surroundings increases more than the entropy of the system decreases
The mechanism for formation of the product X is: A + B → C + D (slow) B + D → X (fast) What is rate limiting step?
The first step
19. What quantities are equal in dynamic equilibrium?
The forward and reverse rates of reactions?
One difference between first and second order reactions is that
The half life of a first order reaction does not depend on starting concentration; the half life of a second order reaction does depend on starting concentration
What does n represent in the equation for ∆G for electrochemical cells?
The number of moles of electrons in the balanced equation
Assuming temperature remains constant, which reaction will be faster: one with a higher activation energy, or one with a lower activation energy?
The one with the lower activation energy
Write the correct equilibrium-constant expression for the reaction below: (NH4)2Se (s) <---> 2NH3 (g) + H2Se (g)
[NH3]^2 [H2Se]
24. How is the reaction quotient used to determine whether a system is at equilibrium?
The reaction is at equilibrium when Q=K
25. If the numerical value of the reaction quotient is greater than the value of the equilibrium constant for a reaction at constant temperature, how will the reaction proceed?
The reaction will shift to form reactants
Define viscosity
The resistance to flow
The rate-limiting step is
The slowest step of a reaction
23. How does the value of K depend on the starting concentrations?
The starting concentrations have no effect on the value of k
Why does reaction rate slow down as time goes on?
There are fewer molecules that can collide
Common solvents for experiments include acetone (CH3COCH3), methanol (CH3OH), water, and toluene (C6H5CH3). Which of these is the best solvent for nonpolar solutes?
Toluene
How can a molecule move to increase entropy?
Translational, vibrational, rotational
What is an activated complex (transition state)?
Unstable combination of reactant species representing the highest energy state of a reaction
46. What would happen to the volume of a gas if the pressure is doubled (say from 1 atm to 2 atm)? Assume temperature is constant.
Volume is halved
38. The magnitude of Kw indicates that
Water autoionizes only to a very small extent
28. A reaction that is spontaneous
Will proceed without outside intervention
Which noble gas is expected to show the largest deviations from the ideal gas behavior? A. He B. Ne C. Ar D. Kr E. Xe
Xenon
Which of the following aqueous solutions has the lowest [OH-]? A. a solution with a pH of 3.0 B. a 1 x 10^-4 M solution of nitric acid C. a solution with pOH of 12.0 D. pure water E. a 1 x 10^-3 M solution of ammonium chloride
a solution with a pOH of 12.0
Lower blood pH leads to:
acidosis
Higher blood pH leads to:
alkalosis
Large intermolecular forces in a substance are manifested by ________. A. low vapor pressure B. high boiling point C. high heat of fusion D. high heat of vaporization E. all of the above
all of the above
The van der Waals equation for real gases recognizes that ________. A. gas particles have non-zero volumes and interact with each other B. molar volumes of gases of different types are different C. the non-zero volumes of gas particles effectively decrease the amount of "empty space" between them D. the molecular attractions between particles of gas decreases the pressure exerted by the gas E. all of the above statements are true
all of the above
What can stop a beta particle?
aluminum
What is solvation?
an exothermic process in which intermolecular attractive forces between solute and solvent are established
Mean free path
average distance a molecule travels between collisions
For the elementary reaction NO3 + CO → NO2 + CO2 what is the molecularity of the reaction?
bimolecular
A reversible process is one that ________. A. can be run backward with no net change in either system or surroundings B. happens spontaneously C. is spontaneous in both directions D. is spontaneous at only high temperatures E. is spontaneous at only low temperatures
can be run backward with no net change in either the system or the surroundings
Closed system:
can exchange energy with the surroundings, but not matter
What is a polyproptic acid?
capable of dislocating more than one proton in water (H2SO4)
The rate of a reaction depends on ________.
collision frequency, collision energy, collision orientation
Graph of a zero order reaction is linear if:
concentration of reactant v. time
Metallic solid conductive or not? why?
conductive; tons of delocalized electrons
The entropy of the universe is ________.
continually increasing
What does a hypertonic solution lead to?
crenation; red blood cells shrivel due to loss of water by osmosis
As the concentration of a solute in a solution increases, the freezing point of the solution ________ and the vapor pressure of the solution ________.
decreases, decreases
Hydrogen bonding is a special case of:
dipole-dipole forces
What types of intermolecular forces are present between a molecule of NH3 and a molecule of H2S?
dispersion and dipole-dipole
Which one of the following processes produces a decrease of the entropy of the system? A. dissolving oxygen gas in water B. sublimation of naphthalene C. dissolving sodium chloride in water D. boiling of alcohol E. exploding of nitroglycerin
dissolving oxygen gas in water
What accompanies the loss of a nuclear particle (alpha and beta decay)?
gamma emission
In general, as activation energy increases, reaction rate ________.
goes down regardless of whether the reaction is exothermic or endothermic
In general, as temperature goes up, reaction rate ________.
goes up regardless of whether the reaction is exothermic or endothermic
metallic solid melting and boiling point
high
Gamma rays are also known as
high energy photons; electromagnetic radiation
Beta particles are also known as:
high speed electrons
A solution is prepared by dissolving 0.23 mol of hypochlorous acid and 0.27 mol of sodium hypochlorite in water sufficient to yield 1.00 L of solution. The addition of 0.05 mol of HCl to this buffer solution causes the pH to drop slightly. The pH does not decrease drastically because the HCl reacts with the ________ present in the buffer solution. The Ka of hypochlorous acid is 1.36 × 10^-3.
hypochlorite ion
Red blood cells are placed in a ___________ solution, leading to hemolysis.
hypotonic (meaning higher solute concentration inside the cell than outside)
A reaction was found to be third order in A. Increasing the concentration of A by a factor of 3 will cause the reaction rate to ________.
increase by a factor of 27
How to increase number of micro states?
increase temperature, increase molecules, increase volume
Consider the following reaction at equilibrium: 2CO2 (g) <---> 2CO (g) + O2 (g) ΔH° = -514 kJ Le Châtelier's principle predicts that removing O2 (g) from the reaction container will ________. A. increase the partial pressure of CO B. decrease the partial pressure of CO C. increase the partial pressure of CO2 D. increase the value of the equilibrium constant E. decrease the value of the equilibrium constant
increase the partial pressure of CO
For the endothermic reaction CaCO3 (s) <---> CaO (s) + CO2 (g) Le Châtelier's principle predicts that ________ will result in an increase in the number of moles of CO2. A. increasing the temperature B. decreasing the temperature C. increasing the pressure D. removing some of the CaCO3(s) E. none of the above
increasing the temperature
Metallic solid soluble or not
insoluble
covalent network solid soluble or not
insoluble
Is a spontaneous process irreversible or reversible?
irreversible
If the rate law for the reaction 2A + 3B → products is second order in A and first order in B, then the rate law is rate = ________.
k[A]2[B]
Oxidation is the ________ and reduction is the ________.
loss of electrons, gain of electrons
molecular solid melting point
low
When do gases behave ideally?
low pressure and high temperature
metallic solid malleable or not
malleable
Alpha particles are attracted to
negatively charged plates
Are gamma rays charged?
no
Can reaction rate be negative?
no
covalent network solid conductive or not? why?
not; no delocalized electrons
molecular solid conductive or not? why?
not; no free ions
Hypertonic:
of greater osmotic pressure
Hypertonic
of greater osmotic pressure (more solute)
hypotonic
of less osmotic pressure
A match will burn more vigorously in pure oxygen than in air because ________.
oxygen is a reactant in combustion and concentration of oxygen is higher in pure oxygen than is in air
What could stop an alpha particle?
paper
beta particles are attracted to
positively charged plates
What affects reaction rate?
presence of a catalyst, concentration, state of reactants, temperature
For the elementary reaction NO3 + CO → NO2 + CO2 what is the rate law?
rate = k [NO3] [CO]
Is the dissociation of water reactant or product favored?
reactant
The equilibrium constant for the gas phase reaction N2 (g) + O2 (g) <---> 2NO (g) is Keq = 4.20 × 10^-31 at 30 °C. At equilibrium, ________. A. products predominate B. reactants predominate C. roughly equal amounts of products and reactants are present D. only products are present E. only reactants are present
reactants predominate
The equilibrium-constant expression for a reaction written in one direction is the ________ of the one for the reaction written for the reverse direction.
reciprocal
Why is crenation bad?
red blood cells cannot carry oxygen as efficiently
Oxidation cannot occur without
reduction
Which process is not spontaneous? A. dry ice sublimating at room temperature B. salt water separating into sodium chloride crystals and pure water C. soup boiling at 120 oC D. perfume diffusing throughout a room
salt water separating into Na+ and Cl- crystals and pure water
For the reaction 2 C4H10 (g) + 13 O2 (g) → 8 CO2 (g) + 10 H2O (g) ΔH° is -125 kJ/mol and ΔS° is +253 J/K ∙ mol. This reaction is ________. A. spontaneous at all temperatures B. spontaneous only at high temperatures C. spontaneous only at low temperatures D. nonspontaneous at all temperatures
spontaneous at all temperatures
The equilibrium-constant expression depends on the ________ of the reaction.
stoichiometry
nitric acid: strong or weak
strong
What is an Arrhenius acid?
substance that dissociates in aqueous solution to form hydrogen ions
What js an Arrhenius base?
substance that dissociates in water to release OH-
A 0.100 m solution of which one of the following solutes will have the highest vapor pressure? A. potassium perchlorate B. calcium perchlorate C. aluminum perchlorate D. sucrose E. NaCl
sucrose
The property responsible for the "beading up" of water is ________.
surface tension
In general, the vapor pressure of a substance increases as ________ increases.
temperature
The phenomenon used to differentiate colloids and true solutions is called what?
the Tyndall effect
What is ∆G a measure of?
the amount of useful work a reaction can do
Beta emission is equivalent to
the conversion of a neutron to a proton
When a system is at equilibrium, ________. A. the reverse process is spontaneous but the forward process is not B. the forward process is spontaneous but the reverse process is not C. both forward and reverse processes have stopped D. the process is not spontaneous in either direction
the process is not spontaneous in either direction
The rate law for a reaction is rate = k[A][B] Which one of the following statements is false? A. The reaction is first order overall. B. The reaction is first order in A. C. The reaction is first order in [B]. D. k is the reaction rate constant E. If [A] is doubled, the reaction rate will increase by a factor of 2.
the reaction is first order overall
Why are LDFs the weakest?
they are not permanent
What kind of metal creates an acidic solution?
transition metal
A neutralization reaction between an acid and a metal hydroxide produces ________.
water and a salt
Benzoic Acid: strong or weak
weak
acetic acid: strong or weak
weak
The principal reason for the extremely low solubility of NaCl in benzene (C6H6) is:
weak salvation of Na+ and Cl- by benzene
Which one of the following is always positive when a spontaneous process occurs? A. ΔSsystem B. ΔSsurroundings C. ΔSuniverse D. ΔHuniverse E. ΔHsurroundings
∆Suniverse
