Q&A Hero

Q: A 34.5-L sample of a gaseous hydrocarbon, measured at 1.00 atm pressure and 25.0ºC, is burned in excess oxygen, liberating 2.20x103kJ of heat at constant pressure. What is the identity of the hydrocarbon? (R=0.0821L·atm/(K·mol)) SubstanceHºf(kJ/mol)CO2(g)-393.5H2O(l)-285.8A) propylene (C3H6, Hºf= 20.41 kJ/mol)B) ethylene (C2H4, Hºf= 52.47 kJ/mol)C) acetylene (C2H2, Hºf= 226.73 kJ/mol)D) ethane (C2H6, Hºf= "84.68 kJ/mol)E) propane (C3H8, Hºf= "104.7 kJ/mol)

Q: What is Hº for the following phase change?KCl(s) → KCl(l)SubstanceHºf(kJ/mol)KCl(s)-436.68KCl(l)-421.79A) 858.47 kJB) 14.89 kJC) -858.47 kJD) -14.89 kJE) 0 kJ

Q: Which of the following reactions corresponds to the thermochemical equation for the standard enthalpy of formation of N,N-diethyl-m-toluamide, C12H17NO(l), the active ingredient in some insect repellents?A) 12C(l) + 17H(l) + N(l) + O(l) →C12H17NO(l)B) 12C(g) + 17H(g) + N(g) + O(g) →C12H17NO(g)C) 12C(s) + 17H(g) + N(g) + O(g) →C12H17NO(l)D) 12C(s) + H2(g) + N2(g) + O2(g) →C12H17NO(l)E) 12C(g) + 17H(g) + N(g) + O(g) →C12H17NO(l)

Q: The enthalpy change at 1 atm of which reaction corresponds to the standard enthalpy of formation of solid magnesium nitrate, Mg(NO3)2?A) Mg2+(g) + 2NO3-(g) →Mg(NO3)2(s)B) Mg(s) + N2(g) + 3O2(g) →Mg(NO3)2(s)C) Mg(g) + 2N(g) + 6O(g) →Mg(NO3)2(s)D) Mg(s) + N2(g) + 2O3(g) →Mg(NO3)2(s)E) Mg2+(aq) + 2NO3-(aq) →Mg(NO3)2(s)

Q: The balanced equation representing the standard enthalpy of formation reaction for NH3(g) isA) N(g) + H2(g) →NH3(g).B) N2(g) + 3H(g) →NH3(g).C) N(g) + 3H(g) →NH3(g).D) N2(g) + H2(g) →NH3(g).E) N2(g) + H2(g) →NH3(g).

Q: For which of the following equations is the enthalpy change at 1 atm pressure equal to the standard enthalpy of formation of liquid formic acid, HCOOH?A) C(g) + 2H(g) + 2O(g) →HCOOH(l)B) C(s) + 2H(g) + 2O(g) →HCOOH(l)C) C(s) + H2(g) + O2(g) →HCOOH(l)D) CO(g) + H2O(l) →HCOOH(l)E) CO2(g) + H2(g) →HCOOH(l)

Q: The enthalpy change at 1 atm of which reaction corresponds to the standard enthalpy of formation of solid potassium bromate, KBrO3?A) K(s) + Br(g) + 3O(g) →KBrO3(s)B) K(g) + Br(g) + 3O(g) →KBrO3(s)C) K(g) + Br2(g) + O2(g) →KBrO3(s)D) K(s) + Br2(l) + O2(g) →KBrO3(s)E) K(s) + Br2(g) + O2(g) →KBrO3(s)

Q: The standard enthalpy change for which of the following processes corresponds to the standard enthalpy of formation of solid cesium fluoride?A) Cs(s) + F2(s) →CsF(s)B) Cs(g) + F2(g) →CsF(g)C) Cs(g) + F(g) →CsF(s)D) Cs(s) + F2(g) →CsF(s)E) Cs(s) + F2(s) →CsF(g)

Q: Which of the following reactions corresponds to the thermochemical equation for the standard enthalpy of formation of solid lead (II) nitrate?A) Pb2+(aq) + 2NO3-(aq) →Pb(NO3)2(s)B) Pb(OH)2(s) + 2HNO3(aq) →Pb(NO3)2(s) + 2H2O(l)C) Pb(s) + N2(g) + 3O2(g) →Pb(NO3)2(s)D) Pb(s) + 2HNO3(aq) →Pb(NO3)2(s) + H2(g)E) Pb(s) + 2N(g) + 6O(g) →Pb(NO3)2(s)

Q: Which of the following has a standard enthalpy of formation value of zero at 25ºC?A) C6H12O6(s)B) S8(s)C) FeSO4(s)D) H2O(l)E) FeSO4(aq)

Q: Which of the following species does nothave a standard enthalpy of formation equal to zero at 25ºC?A) Cl2(l)B) N2(g)C) Fe(s)D) H+(aq)E) S8(s)

Q: Which substance has a standard enthalpy of formation equal to zero at 25ºC?A) C2H6(g)B) Br2(g)C) Br2(l)D) Br2(s)E) C2H6(l)

Q: All of the following have a standard enthalpy of formation value of zero at 25ºC exceptA) C(s).B) Ne(g).C) Fe(s).D) F2(g).E) CO(g).

Q: Which of the following has a standard enthalpy of formation value of zero at 25ºC?A) O2(g)B) O3(g)C) O2(l)D) O(g)E) O2(s)

Q: Which of the following has a standard enthalpy of formation value of zero at 25ºC?A) Cl(g)B) Cl2(l)C) Cl2(g)D) Cl(s)E) Cl2(s)

Q: Given thatO(g) + e-→O-(g); Hº= -142 kJO(g) + 2e-→O2-(g); Hº= 702 kJthe enthalpy change for the reaction represented by the equationO-(g) + e-→O2-(g) isA) 0 kJ.B) -560 kJ.C) -844 kJ.D) 844 kJ.E) 560 kJ.

Q: What is the standard enthalpy of formation of liquid methylamine (CH3NH2)?C(s) + O2(g) →CO2(g); Hº= -393.5 kJ2H2O(l) →2H2(g) + O2(g); Hº= 571.6 kJN2(g) + O2(g) →NO2(g); Hº= 33.10 kJ4CH3NH2(l) + 13O2(g) →4CO2(g) + 4NO2(g) + 10H2O(l); Hº= -4110.4 kJA) +3899.2 kJ/molB) -3899.2 kJ/molC) -47.3 kJ/molD) +47.3 kJ/molE) +3178.4 kJ

Q: Given the following thermochemical data at 25ºC and 1 atm pressure,O2(g) + 2B(s) →B2O3(s); Hº= -1264 kJO3(g) + 2B(s) →B2O3(s); Hº= -1406 kJdetermine Hº for the following reaction at 25ºC and 1 atm pressure.3O2(g) →2O3(g)A) -980 kJ/molB) +284 kJ/molC) +980 kJ/molD) -2670 kJ/molE) -284 kJ/mol

Q: Consider the following changes at constant temperature and pressure:H2O(s) →H2O(l); H1H2O(l) →H2O(g); H2H2O(g) →H2O(s); H3Using Hess's law, the sum H1+ H2+ H3 isA) equal to zero.B) sometimes greater than zero and sometimes less than zero.C) less than zero.D) cannot be determined without numerical values for H.E) greater than zero.

Q: Using two or more of the following,N2(g) + O2(g) →N2O3(s); Hº= 83.7 kJN2(g) + O2(g) →2NO(g); Hº= 180.4 kJN2(g) + O2(g) →NO2(g); Hº= 33.2 kJN2(g) + H2(g) →NH3(g); Hº= -45.9 kJdetermine Hº for the following reaction.NO(g) + NO2(g) →N2O3(g)A) -39.7 kJB) 24.3 kJC) -207.1 kJD) 39.7 kJE) 207.1 kJ

Q: Given the following data, calculate the standard enthalpy of reaction for the conversion of buckminsterfullerene (C60) into diamond: C(graphite) →C(diamond); Hº= +1.897 kJ60C(graphite) →C60(fullerene); Hº= +2193 kJA) -35 kJB) 35 kJC) -2191 kJD) 2191 kJE) 38 kJ

Q: Using the following data, calculate the standard enthalpy of reaction for the coal gasification process 2C(s) + 2H2O(g) →CH4(g) + CO2(g).C(s) + H2O(g) →CO(g) + H2(g); Hº= +131.3 kJCO(g) + H2O(g) →CO2(g) + H2(g); Hº= -41.2 kJCO(g) + 3H2(g) →CH4(g) + H2O(g); Hº= -206.1 kJA) -116.0 kJB) 378.6 kJC) +15.3 kJD) -157.2 kJE) -378.6 kJ

Q: The overall chemical equation resulting from the sum of the following three steps is2C(s) + 2H2O(g) → 2CO(g) + 2H2(g)CO(g) + H2O(g) → CO2(g) + H2(g)CO(g) + 3H2(g) → CH4(g) + H2O(g)A) 2C(s) + 2H2O(g) → CO2(g) + CH4(g)B) 2C(s) + 3H2O(g) → CO(g) + CO2(g) + 3H2(g)C) 2C(s) + H2O(g) + H2(g)→ CO(g) + CH4(g)D) 2CO(g) + 2H2(g) → CH4(g) + CO2(g)E) 2C(s) + CH4(g) + 3H2O(g) →3CO(g) + 5H2(g)

Q: Given:Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g); Hº= -26.8 kJFeO(s) + CO(g) → Fe(s) + CO2(g); Hº= -16.5 kJdetermine Hº for the following thermochemical equation.Fe2O3(s) + CO(g) → 2FeO(s) + CO2(g)A) 6.2 kJB) 10.3 kJC) 22.7 kJD) -10.3 kJE) -43.3 kJ

Q: Given:Pb(s) + PbO2(s) + 2H2SO4(l) → 2PbSO4(s) + 2H2O(l); Hº= -509.2 kJSO3(g) + H2O(l) → H2SO4(l); Hº= -130. kJdetermine Hº for the following thermochemical equation.Pb(s) + PbO2(s) + 2SO3(g)→2PbSO4(s)A) 3.77 x 103kJB) -521 kJC) -3.77 x 103kJD) -639 kJE) -769 kJ

Q: Combustion of 7.21g of liquid benzene (C6H6) causes a temperature rise of 50.3ºC in a constant-pressure calorimeter that has a heat capacity of 5.99kJ/ºC. What is H for the following reaction?C6H6(l)+O2(g)→6CO2(g)+3H2O(l)A) -302 kJ/molB) 41.8 kJ/molC) -41.8 kJ/molD) -3.27 x103 kJ/molE) 302 kJ/mol

Q: When 50.0 mL of 1.20M of HCl(aq) is combined with 50.0 mL of 1.30M of NaOH(aq) in a coffee-cup calorimeter, the temperature of the solution increases by 8.01ºC. What is the change in enthalpy for this balanced reaction?HCl(aq)+NaOH(aq)→NaCl(aq)+H2O(l)Assume that the solution density is 1.00 g/mL and the specific heat capacity of the solution is 4.18 J/g·ºC.A) -55.8 kJB) 55.8 kJC) 51.5 kJD) -51.5 kJE) -26.8 kJ

Q: When 0.0600mol of HCl(aq) is reacted with 0.0600mol of NaOH(aq) in 50.0 mL of water, the temperature of the solution increases by 15.1ºC. What is the enthalpy of reaction for the following thermochemical equation?HCl(aq)+NaOH(aq)→NaCl(aq)+H2O(l)Assume that the heat capacity of the solution and calorimeter is 221.3J/ºC.A) -0.201 kJB) 55.8 kJC) -3.35 kJD) -55.8 kJE) 3.35 kJ

Q: When 7.13g of methane (CH4) is burned in a bomb calorimeter (heat capacity = 2.677x103J/C), the temperature rises from 24.00 to 27.08ºC. How much heat is absorbed by the calorimeter?CH4(g)+2O2(g)→CO2(g)+2H2O(l); Hº=-1283.8kJA) 562 kJB) 3.66 x 103kJC) 8.24 kJD) 571 kJE) 1.28 x 103kJ

Q: A bomb calorimeter has a heat capacity of 2.47kJ/K. When a 0.105-g sample of a certain hydrocarbon was burned in this calorimeter, the temperature increased by 2.14K. Calculate the energy of combustion for 1 g of the hydrocarbon.A) -5.29 J/gB) J/gC) -0.120 J/gD) J/gE) -0.560 J/g

Q: In a bomb calorimeter, reactions are carried outA) at 1 atm pressure and 0ºC.B) at a constant pressure.C) at a constant volume.D) at a constant pressure and 25ºC.E) at 1 atm pressure and 25ºC.

Q: A 500-cm3 sample of 1.0 M NaOH(aq) is added to 500 cm3 of 1.0 M HCl(aq) in a Styrofoam cup, and the solution is quickly stirred. The rise in temperature (T1) is measured. The experiment is repeated using 100 cm3of each solution, and the rise in temperature (T2) is measured. What conclusion can you draw about T1 and T2?HCl(aq) + NaOH(aq) →H2O(l) + NaCl(aq); Hº= -55.8 kJA) T2 is greater than T1.B) T2 is equal to T1.C) T1 is five times as large as T2.D) T1 is less than T2.E) T2 is five times as large as T1.

Q: A 94.7-g sample of silver (s=0.237J/(g·ºC)), initially at 348.25ºC, is added to an insulated vessel containing 143.6g of water (s=4.18 J/(g·ºC)), initially at 13.97ºC. At equilibrium, the final temperature of the metal-water mixture is 22.63ºC. How much heat was absorbed by the water? The heat capacity of the vessel is 0.244kJ/C.A) 5.20 kJB) 3.09 kJC) 7.31 kJD) 9.12 kJE) 129 kJ

Q: How much heat must be applied to a 18.3-g sample of iron (s=0.449J/(g·ºC)) in order to raise its temperature from 23.8ºC to 356.6ºC?A) 2.93 x 103JB) 2.73 x 103JC) 1.96 x 102JD) 6.09 x 103JE) 1.49 x 102J

Q: A 42.9-g sample of cobalt (s=0.421J/(g·ºC)), initially at 157.2ºC, is placed in an insulated vessel containing 120.9g of water (s=4.18J/(g·ºC)), initially at 19.2ºC. Once equilibrium is reached, what is the final temperature of the metal-water mixture? Neglect the heat capacity of the vessel.A) 24.0ºCB) 55.3ºCC) 14.1ºCD) 88.2ºCE) 31.8ºC

Q: A 85.9-g piece of cobalt (s=0.421J/(g·ºC)), initially at 263.1ºC, is added to 116.2g of a liquid, initially at 24.7ºC, in an insulated container. The final temperature of the metal-liquid mixture at equilibrium is 50.8ºC. What is the identity of the liquid? Neglect the heat capacity of the container.A) hexane (s= 2.27 J/(g·ºC))B) methanol (s= 2.53 J/(g·ºC))C) acetone (s= 2.15 J/(g·ºC))D) ethanol (s= 2.43 J/(g·ºC))E) water (s= 4.18 J/(g·ºC))

Q: Exactly 105.2J will raise the temperature of 10.0g of a metal from 25.0ºC to 60.0ºC. What is the specific heat capacity of the metal?A) 0.301 J/(g·ºC)B) 3.33 J/(g·ºC)C) 29.3 J/(g·ºC)D) 25.2 J/(g·ºC)E) none of these

Q: A 170.0-g sample of metal at 79.00ºC is added to 170.0g of H2O(l) at 14.00ºC in an insulated container. The temperature rises to 16.19ºC. Neglecting the heat capacity of the container, what is the specific heat of the metal? The specific heat of H2O(l) is 4.18 J/(g·ºC).A) 4.18 J/(g·ºC)B) 120 J/(g·ºC)C) 0.146 J/(g·ºC)D) -0.146 J/(g·ºC)E) 28.6 J/(g·ºC)

Q: Which of the following processes will result in the lowest final temperature of the metal"water mixture at equilibrium? The specific heat of cobalt is 0.421J/(g·ºC).A) the addition of 100 g of cobalt at 95ºC to 80 mL of water at 25ºC in an insulated containerB) the addition of 100 g of cobalt at 95ºC to 100 mL of water at 25ºC in an insulated containerC) the addition of 100 g of cobalt at 95ºC to 40 mL of water at 25ºC in an insulated containerD) the addition of 100 g of cobalt at 95ºC to 20 mL of water at 25ºC in an insulated containerE) the addition of 100 g of cobalt at 95ºC to 60 mL of water at 25ºC in an insulated container

Q: Which of the following processes will result in the lowest final temperature of the metal"water mixture at equilibrium?A) the addition of 100 g of silver (s= 0.237 J/(g·ºC)) at 95C to 100 mL of water at 25ºC in an insulated containerB) the addition of 100 g of cobalt (s= 0.418 J/(g·ºC)) at 95C to 100 mL of water at 25ºC in an insulated containerC) the addition of 100 g of chromium (s= 0.447 J/(g·ºC)) at 95C to 100 mL of water at 25ºC in an insulated containerD) the addition of 100 g of copper (s= 0.385 J/(g·ºC)) at 95C to 100 mL of water at 25ºC in an insulated containerE) the addition of 100 g of gold (s= 0.129 J/(g·ºC)) at 95C to 100 mL of water at 25ºC in an insulated container

Q: How much heat is gained by copper when 51.8g of copper is warmed from 15.5ºC to 76.4ºC? The specific heat of copper is 0.385J/(g·ºC).A) 3.09 x 102JB) 29.41 JC) 23.45 JD) 1.21 x 103JE) 1.52 x 103J

Q: It is relatively easy to change the temperature of a substance that A) is very massive. B) is an insulator. C) has a high specific heat capacity. D) has a low specific heat capacity. E) is brittle.

Q: Two metals of equal mass with different heat capacities are subjected to the same amount of heat. Which undergoes the smaller change in temperature? A) The metal with the higher heat capacity undergoes the smaller change in temperature. B) Both undergo the same change in temperature. C) You need to know the initial temperatures of the metals. D) You need to know which metals you have. E) The metal with the lower heat capacity undergoes the smaller change in temperature.

Q: A 100 g sample of each of the following metals is heated from 35ºC to 45ºC. Which metal absorbs the lowest amount of heat energy?MetalSpecific Heatcopper0.385 J/(g·ºC)magnesium1.02 J/(g·ºC)mercury0.138 J/(g·ºC)silver0.237 J/(g·ºC)lead0.129 J/(g·ºC)A) leadB) magnesiumC) silverD) mercuryE) copper

Q: The molar heat capacity of gaseous heptane at 25.0ºC is 165.2J/(mol·ºC). What is its specific heat?A) 0.6065 J/(g·ºC)B) 1.649 J/(g·ºC)C) 6.041 x 10-5J/(g·ºC)D) 165.2 J/(g·ºC)E) 1.655 x 104J/(g·ºC)

Q: The heat required to raise the temperature of 52.00g of chromium by 1ºC is called itsA) heat of vaporization.B) specific heat.C) heat of fusion.D) entropy.E) molar heat capacity.

Q: The specific heat capacity of copper is 0.384 J/g.ºC. What is the molar specific heat capacity of this substance? The molar mass of copper is 63.54 g/mol.A) 24.4 J/mol.°CB) 0.00604 J/mol.°CC) 165 J/mol.°CD) 0.384 J/mol.°CE) 2.60 J/mol.°C

Q: The units for specific heat areA) J/(g·ºC).B) (J·ºC).C) J/g.D) J/C.E) (J·g).

Q: The units for heat capacity areA) J/g.B) (J·g).C) J/C.D) (J·ºC).E) J/(g·ºC).

Q: The quantity of heat required to raise the temperature of a sample of a substance by 1ºC is the sample'sA) work.B) calorimetry.C) heat capacity.D) specific heat.E) enthalpy.

Q: From a consideration of the van der Waals constants for water and sulfur dioxide, a (atm×L2/mol2) b(L/mol)H2O5.540.0305SO26.87 0.0568we can conclude thatA) H2O molecules are smaller and less attracted to each other than SO2 molecules.B) H2O molecules are larger and less attracted to each other than SO2 molecules.C) H2O molecules are larger and more attracted to each other than SO2 molecules.D) H2O molecules are equivalent to SO2molecules in size and attraction to each other.E) H2O molecules are smaller and more attracted to each other than SO2 molecules.

Q: In the van der Waals equation, the effect of intermolecular forces is accounted for by A) T. B) V. C) b. D) a. E) P.

Q: Using the van der Waals equation, determine the pressure of 459.0g of SO2(g) in a 4.40-L vessel at 625K. For SO2(g), a=6.865 L2"¢atm/mol2and b=0.05679L/mol. (R=0.0821L"¢atm/(K"¢mol))A) 110 atmB) 8.06 atmC) 73.9 atmD) 83.6 atmE) 8.36 atm

Q: Which of the following statements concerning gas molecules is incorrect? A) Attraction is greater between fast-moving molecules than between slow-moving molecules. B) Real molecules have a weak attraction for each other. C) Real molecules have the greatest attraction for each other at low temperatures. D) Real molecules have the greatest attraction for each other at high pressures. E) Real molecules occupy a finite space.

Q: At 320 K and 16 atm pressure, the molar volume of ammonia, NH3, is about 10% less than the molar volume of an ideal gas. The best explanation for actual volume being this much smaller than ideal volume is that A) the intermolecular forces of attraction become significant at this temperature and this pressure. B) the critical temperature and pressure of NH3(405 K and 112 atm) are too close to the actual temperature and pressure of the NH3above. C) at this high temperature, a significant amount of NH3decomposes to N2and H2. D) ammonia is a real gas and not an ideal gas. E) the volume occupied by the NH3molecules themselves is significant at this high concentration.

Q: Real gases deviate from ideal behavior for two reasons: (1) real gas molecules have intermolecular forces, and (2) real gas molecules have A) pressures within the chemical bonds. B) nonzero molecular volumes. C) ionization energies. D) molecular vibrations. E) a distribution of molecular speeds.

Q: Under what set of conditions does HCl(g) deviate the most from ideal behavior? A) standard temperature and pressure B) high temperature and low pressure C) low temperature and high pressure D) low temperature and low pressure E) high temperature and high pressure

Q: If 250 mL of methane, CH4, effuses through a small hole in 28s, the time required for the same volume of helium to pass through the hole under the same conditions will be A) 56 s. B) 7 s. C) 1.8 s. D) 14 s. E) 112 s.

Q: The molar mass of an unknown gas was measured by an effusion experiment. It was found that it took 63s for the gas to effuse, whereas nitrogen gas required 48s. The molar mass of the gas isA) 24 g/mol.B) 37 g/mol.C) 16 g/mol.D) 32 g/mol.E) 48 g/mol.

Q: Which of the following gases will have the slowest rate of effusion at constant temperature?A) H2B) F2C) NeD) SO3E) CF4

Q: What is the ratio of the average rate of effusion of NOF(g) to that of HBr(g) at 400 K? A) 81:49 B) 7:9 C) 49:81 D) 9:7 E) The average rate of effusion is the same for the two gases.

Q: Which of the following relates the rate of effusion of a gas to the square root of its molar mass? A) Boyle's law B) Graham's law C) Charles's law D) Dalton's law E) Avogadro's hypothesis

Q: What is the ratio of the average speed of CH4 molecules to that of SO2 molecules at 298 K?A) 1:1B) 1:2C) 1.4:1D) 1:1.4E) 2:1

Q: Calculate the root-mean-square velocity for the O2 molecules in a sample of O2gas at 24.3ºC. (R=8.3145J/K·mol)A) 15.22 m/sB) 137.6 m/sC) 277.9 m/sD) 481.4 m/sE) 9.167 x1026m/s

Q: Molecular speed distributions for a gas at two different temperatures are shown below. Which of the following graphs correctly describes the distributions at the two temperatures, where T2> T1? NOTE: The small vertical lines indicate average speed.A) B) C) D) E) none of the above

Q: What is the ratio of the average speed of SO2 molecules to that of oxygen molecules at 298 K?A) : B) : C) 2:1D) 1:2E) 1:1

Q: At STP, as the molar mass of the molecules that make up a pure gas increases, the A) root mean square speed of the molecules increases. B) root mean square speed of the molecules decreases. C) root mean square speed of the molecules remains constant. D) root mean square speed increases to a maximum, then decreases. E) none of the above.

Q: According to the postulates of the kinetic theory of gases, the root-mean-square (rms) speed of the molecules of a given gas is proportional to the A) reciprocal of the absolute temperature. B) Celsius temperature squared. C) absolute temperature. D) square root of the absolute temperature. E) absolute temperature squared.

Q: Which of the following statements concerning a sample of oxygen gas at 1.00 atm pressure is incorrect? A) The molecules are in constant rapid random motion. B) The pressure exerted by gaseous oxygen is due to the impact of the molecules with the walls of the container. C) The average kinetic energy of the gaseous oxygen is inversely proportional to the absolute temperature of the gas. D) The volume occupied by the oxygen molecules is negligible compared with the size of the container. E) Collisions between the gaseous molecules are elastic.

Q: A sealed 22.4 L flask contains pure O2 at STP. A second sealed 22.4 L flask contains CH4 at STP. Which of the following statements concerning the molecules in the flasks is/are true?1) The average kinetic energy of the O2molecules is greater than the average kinetic energy of CH4molecules.2) The average velocity of the CH4molecules is greater than the average velocity of the O2molecules.3) The volume occupied by the gas molecules in both flasks is small relative to the total volume of the flasks.A) 1 onlyB) 2 onlyC) 3 onlyD) 2 and 3E) 1, 2, and 3

Q: If a sample of nitrogen gas in a sealed container of fixed volume is heated from 25ºC to 150ºC, the value of which of the following quantities will remain constant?A) the average speed of the moleculesB) the density of the nitrogenC) the average intensity of a molecular collision with the walls of the containerD) the average kinetic energy of the moleculesE) the pressure of the gas

Q: Which of the following statements is least likely to be true of a sample of nitrogen gas at STP?A) Collisions between the gaseous molecules are elastic.B) The intermolecular forces between nitrogen molecules are not negligible.C) Molecules of gaseous nitrogen are in constant random motion.D) The average kinetic energy of the gaseous nitrogen is proportional to the absolute temperature of the gas.E) The pressure exerted by gaseous nitrogen is due to collisions of the molecules with the walls of the container.

Q: Which of the following is not a postulates of the kinetic molecular theory of gases?A) The gas molecules are in constant motion.B) At a constant temperature, each molecule has the same kinetic energy.C) The collisions between molecules are elastic.D) The volumes of the molecules are negligible compared with the volume of the container.E) The gas molecules are in rapid motion.

Q: Which of the following is included as a postulate in the kinetic molecular theory of an ideal gas? A) Collisions between molecules are all elastic. B) All molecules move randomly in zigzag directions. C) The distance between gas molecules is small compared with the size of the molecule. D) All the molecules have the same velocity. E) In an average collision between molecules, both molecules have the same kinetic energy.

Q: Which statement is inconsistent with the kinetic theory of an ideal gas?A) Most of the volume occupied by a gas is empty space.B) The forces of repulsion between gas molecules are very weak or negligible.C) Gas molecules move in a straight line between collisions.D) The average kinetic energy of a gas is proportional to the absolute temperature.E) The collisions between gas molecules are inelastic.

Q: A small amount wet of hydrogen gas (H2) can be prepared by the reaction of zinc with excess hydrochloric acid and trapping the gas produced in an inverted tube initially filled with water. If the total pressure of the gas in the collection tube is 729.7 mmHg at 25ºC, what is the partial pressure of the hydrogen? The vapor pressure of water is 23.8 mmHg.A) 705.9 mmHgB) 753.5 mmHgC) 729.7 mmHgD) 31.51 mmHgE) 47.60 mmHg

Q: A sample of hydrogen was collected by water displacement at 23.0ºC and an atmospheric pressure of 735 mmHg. Its volume is 568 mL. After water vapor is removed, what volume would the hydrogen occupy at the same conditions of pressure and temperature? (The vapor pressure of water at 23.0ºC is 21 mmHg.)A) 509 mLB) 539 mLC) 552 mLD) 568 mLE) 585 mL

Q: A sample of oxygen is collected over water at a total pressure of 690.7mmHg at 19ºC. The vapor pressure of water at 19ºC is 16.5mmHg. The partial pressure of the O2 isA) 0.9305 atm.B) 0.9349 atm.C) 0.9088 atm.D) 1.070 atm.E) 0.8871 atm.

Q: What is the partial pressure of nitrogen in a container that contains 3.96mol of oxygen, 7.49mol of nitrogen, and 1.19mol of carbon dioxide when the total pressure is 563mmHg? A) 53.0 mmHg B) 819 mmHg C) 176 mmHg D) 334 mmHg E) 563 mmHg

Q: In a mixture of helium and chlorine, occupying a volume of 14.6L at 871.7mmHg and 28.6oC, it is found that the partial pressure of chlorine is 355mmHg. What is the total mass of the sample? A) 50.6 g B) 1.10 g C) 21.1 g D) 1.60 g E) 19.5 g