Q&A Hero

Q: The rate law for the reaction between chlorine and nitric oxide,2NO(g) + Cl2(g) → 2NOCl(g)is Rate = k[NO]2[Cl2]. Which of the following changes will not alter the initial rate of the reaction?A) increasing the concentration of NOClB) decreasing the volume of the reaction systemC) running the reaction in a solvent rather than in the gas phaseD) increasing the volume of the reaction systemE) increasing the concentration of chlorine gas

Q: The rate law for the hydrolysis of thioacetamide (CH3CSNH2),CH3CSNH2(aq) + H2O(l) → H2S(g) + CH3CONH2(aq)is Rate = k[H+][CH3CSNH2]. If, during the course of the reaction, some solid sodium hydroxide is added to the reaction mixture, thenA) the reaction rate decreases, but kremains the same.B) the reaction rate remains the same, but kdecreases.C) the reaction rate increases, but kremains the same.D) there is no change in the reaction rate or the rate constant.E) the reaction rate remains the same, but kincreases.

Q: The acid-catalyzed reaction of acetone, CH3COCH3, with iodine can be represented by the following net reaction:CH3COCH3+ I2 CH2ICOCH3+ H++ I-9It is found experimentally that the rate law for this reaction is Rate = k[CH3COCH3][H+]. Suppose that in trial 1, the initial rate of the reaction is measured with the initial concentrations of acetone, iodine, and hydrogen ion all equal to 0.10 M. Then, in trial 2, the initial rate of the reaction is measured with the initial concentrations all equal to 0.20 M. The initial rate of trial 2 will be larger than the initial rate of trial 1 by a factor ofA) 4.B) 16.C) 8.D) 2.E) 64.

Q: For the reaction A + B + C → products, the following initial-rate data were obtained. [A]0(mol/L)[B]0(mol/L)[C]0(mol/L)Initial Rate (mol/(L·s))0.400.400.200.01600.200.400.400.00800.600.100.200.00150.200.100.200.00050.200.200.400.0020What are the reaction orders with respect to A, B, and C, respectively?A) 0, 1, 1B) 1, 2, 1C) 1, 1, 1D) 1, 2, 0E) 0, 2, 1

Q: Nitrosyl chloride is produced from the reaction of nitrogen monoxide and chlorine:2NO(g) + Cl2(g) → 2NOCl(g)The following initial rates at a given temperature were obtained for the concentrations listed below. ExperimentInitial Rate (mol·L-1·h-1)[NO]0(mol·L-1)[Cl2]0(mol·L-1)12.210.250.25219.890.750.2536.630.250.75From the data, what is the experimental rate law?A) Rate = k[Cl2]B) Rate = k[NO]C) Rate = k[NO][Cl2]2D) Rate = k[NO]2[Cl2]E) Rate = k[NO][Cl2]1/2

Q: The following data were obtained in a kinetics study of the hypothetical reaction A + B + C-products. [A]0(M) [B]0(M) [C]0(M) Initial Rate (10-3M/s) 0.4 0.4 0.2 160 0.2 0.4 0.4 80 0.6 0.1 0.2 15 0.2 0.1 0.2 50.2 0.2 0.4 20Using the initial-rate method, what is the order of the reaction with respect to A?A) first-orderB) zero-orderC) third-orderD) second-orderE) impossible to tell from the data given

Q: If a reaction is zero-order in a reactant, when the concentration of the reactant is decreased by a factor of 2, the reaction rate will A) quadruple. B) decrease by a factor of 1/2. C) remain constant. D) decrease by a factor of 1/4. E) double.

Q: For the reaction(CH3)3CCl(aq) + OH-(aq)→ (CH3)3COH(aq) + Cl-(aq)it is found experimentally that doubling the initial concentration of (CH3)3CCl causes the initial reaction rate to double, but doubling the initial concentration of OH-has no effect on the rate. What is the rate law?A) Rate = k[(CH3)3CCl]2[OH-]B) Rate = k[(CH3)3CCl][OH-]C) Rate = kD) Rate = k[(CH3)3COH][Cl-]E) Rate = k[(CH3)3CCl]

Q: For the reaction between nitrogen monoxide and chlorine to produce nitrosyl chloride, 2NO(g)+Cl2(g) → 2NOCl(g), it is found that tripling the initial concentration of both reactants increases the initial rate by a factor of 27. If only the initial concentration of chlorine is tripled, the initial rate increases by a factor of 3. What is the order of the reaction with respect to Cl2?A) 1/2B) 1C) 2D) 3E) 0

Q: The following data were obtained for the hypothetical reaction 2A + B → products. [A]0(M) [B]0(M) Initial Rate (M/s) 0.2 0.1 50.2 0.2 200.60.1 45What is the overall order of this reaction?A) 3B) 1/2C) 0D) 4E) 1

Q: If a reaction is first-order with respect to a particular reactant, when the concentration of that reactant is increased by a factor of 2, the reaction rate will _____. A) increase by a factor of 2. B) remain constant. C) decrease by a factor of . D) decrease by a factor of . E) increase by a factor of 4.

Q: The rate law for the chemical reaction5Br-(aq) + BrO3-(aq) + 6H+(aq) → 3Br2(aq)+ 3H2O(l)has been determined experimentally to be Rate = k[Br-][BrO3-][H+]2. What is the overall order of the reaction?A) 3B) 5C) 4D) 2E) 1

Q: The hypochlorite ion oxidizes the iodide ion in aqueous solution as represented by the following equation:OCl-(aq) + I-(aq) → OI-(aq) + Cl-(aq)The rate law for this reaction is Rate = k. The overall reaction order and the order with respect to OH-areA) 2 and -1.B) 0 and -1.C) 0 and 1.D) 2 and 1.E) 1 and -1.

Q: The reaction2H2(g) + 2NO(g) → 2H2O(g) + N2(g)is first-order in H2and second-order in NO at a particular temperature. What is the rate law?A) Rate = k[H2]2[NO]2B) Rate = k[H2][NO]2C) Rate = k[H2][NO]D) Rate = k[H2O]2[N2]E) Rate = k[H2]2[NO]

Q: The balanced chemical equation and rate law for the reaction between NO(g) and H2(g) at a particular temperature are2NO(g) + 2H2(g) → N2(g) + 2H2O(g)Rate = k[NO]2[H2]What is the reaction order with respect to hydrogen?A) 4B) 0C) 2D) 3E) 1

Q: Ozone reacts with nitrogen dioxide to produce oxygen and dinitrogen pentoxide according to the following chemical equation:O3(g) + 2NO2(g) → O2(g) + N2O5(g)The rate law for this reaction is Rate = k[O3][NO2]. If concentration is measured in moles per liter and time is measured in seconds, what are the units of k?A) L·mol-1·sB) L2·mol-2·s-1C) L·mol-1·s-1D) mol·L-1·s-1E) mol2·L-2·s-1

Q: A rate constant for a particular reaction is 0.0070 M-1·s-1. What is the overall order of this reaction?A) 2B) 3C) 4D) 0E) 1

Q: Which of the following statements is incorrect? A) The rates of most chemical reactions change with time. B) The rate constant for a reaction can be changed by changing the temperature. C) The rate constant is dependent on the reactant concentrations. D) In a series of stepwise reactions, the rate-determining step is the slowest one. E) The rate of a catalyzed reaction is dependent on the concentration of the catalyst.

Q: Which of the following statements is always true?A) Exothermic reactions have lower activation energies than endothermic reactions.B) The rate of a catalyzed reaction is independent of the concentration of the catalyst.C) The rate for a reaction depends on the concentrations of all the reactants.D) The rate constant is independent of the concentrations of the reacting species.E) The rate law can be determined from the stoichiometric equation.

Q: For a certain first-order reaction with the general form aA → products, the rate is 0.32 M·s-1 when the concentration of the reactant is 0.29M. What is the rate constant for this reaction?A) 0.26 s-1B) 1.1 s-1C) 0.32 s-1D) 3.1 s-1E) 3.8 s-1

Q: The hypochlorite ion oxidizes the iodide ion in aqueous solution as represented by the following equation:OCl-(aq) + I-(aq) → OI-(aq) + Cl-(aq)The rate law for this reaction is Rate = k. If time is measured in seconds and concentration is measured in moles per liter, what are the units for k?A) mol2/(L2·s)B) L/(mol·s)C) 1/sD) L2/(mol2·s)E) mol/(L·s)

Q: If the rate law for a reaction isRate = k[ClO3-][I-][H+]2what are the units of kwhen the unit of time is seconds and the unit of concentration is moles per liter?A) (L·s)/molB) mol2/(L2·s)C) mol/(L·s)D) L2/(mol2·s)E) L3/(mol3·s)

Q: For which of the following hypothetical rate laws would the units of the rate constant have the general form M-2time-1?A) rate = k[A]3B) rate = k[A]4C) rate = k[A]2D) rate = k[A]E) rate = k

Q: For a second-order reaction, what are the possible units of the rate constant?A) L-1·s-1B) mol·L-1·s-1C) sD) L.mol-1·s-1E) mol·L-1

Q: Consider the reactionaA + bB dD + eE C = catalystThe rate law isRate = k[A]q[B]r[C]sWhich of the following statements is incorrect?A) The exponents qand rare always equal to the coefficients a and b, respectively.B) The overall reaction order is q+ r+ s.C) The exponent s must be determined experimentally.D) The symbol krepresents the rate constant.E) The exponents q, r, and sare often integers.

Q: Which of the following statements is true concerning the reaction given below?2H2S(g) + O2(g) → 2S(s) + 2H2O(g)A) The rate law is Rate = k[H2S]2[O2].B) The reaction is second-order in H2S(g) and first-order in O2(g).C) The reaction is first-order in H2S(g) and second-order in O2(g).D) The rate law is Rate = k[H2S][O2].E) The rate law may be determined only by experiment.

Q: Which of the following statements concerning the experimental determination of reaction rates is incorrect? A) To determine reaction rates one of the reactants must be colored. B) Monitoring changes in reactant or product physical properties is a convenient way to determine reaction rates. C) Analysis of samples withdrawn from the reaction solution at varying times is useful for slow reactions. D) Instrumental methods, such as visible spectroscopy, may be used to continuously measure changes in reactants or products. E) Any method of analysis that can determine product or reactant concentrations during the course of the reaction can potentially be used to determine reaction rates.

Q: Which of the following experimental methods cannot be used to measure the rate of a reaction?A) measurement of the absorbance of a colored reactant with timeB) measurement of the change in the partial pressure of a gas-phase product over timeC) measurement of the equilibrium concentration of an acidic product via titration with a strong baseD) measurement of the absorbance of a colored product with timeE) measurement of the change in the partial pressure of a gas-phase reactant over time

Q: In the reaction 2H2O2(aq) → 2H2O(l) + O2(g), the initial concentration of H2O2is 0.542M and, 21.2 seconds later, the concentration of H2O2is 0.310 M. What is the average rate of reaction over this time interval?A) -0.0109 M/sB) 0.0109 M/sC) 0.0146 M/sD) 0.00547 M/sE) -0.00547 M/s

Q: For the reaction of the ammonium ion with nitrous acid, the net reaction isNH4+(aq) + HNO2(aq) → N2(g) + 2H2O(l) + H+(aq)If the initial concentration of nitrous acid is 1.00 Mand, after 28.8 s has elapsed, the concentration of nitrous acid has fallen to 0.82 M, what is the average rate of the reaction over this time interval?A) 0.0063 M/sB) 0.028 M/sC) -0.0063 M/sD) -0.028 M/sE) 0.063 M/s

Q: For the reaction2N2O5(g) → 4NO2(g) + O2(g)which of the following expressions is equal to the rate of the reaction?A) B) C) D) E)

Q: For the hypothetical reaction A + 2B → 2C + D, the initial rate of disappearance of A is 2.0 x 10"2mol/(L·s). What is the initial rate of disappearance of B?A) 8.0 x 10-2mol/(L·s)B) 4.0 x 10-2mol/(L·s)C) 1.4 x 10-1mol/(L·s)D) 4.0 x 10-4mol/(L·s)E) 1.4 x 10-2mol/(L·s)

Q: For the reaction6CH2O(aq) + 4NH3(aq) → (CH2)6N4(aq) + 6H2O(l)the rate of the reaction may be expressed as . What is an equivalent expression for the rate of the reaction?A) B) C) D) E)

Q: For the reactionIO3-(aq) + 5I-(aq)+ 6H+(aq) → 3I2(aq) + 3H2O(l)the rate of disappearance of I-(aq) at a particular time and concentration is 2.6 x 10-3mol/(L·s). What is the rate of appearance of I2(aq)?A) 4.3 x 10-3mol/(L·s)B) 7.8 x 10-3mol/(L·s)C) -1.6x 10-3mol/(L·s)D) 1.6 x 10-3mol/(L·s)E) 6.4 x 10-3mol/(L·s)

Q: The oxidation of ammonia produces nitrogen and water via the following reaction:4NH3(g) + 3O2(g) → 2N2(g) + 6H2O(l)Suppose the rate of formation of H2O(l) is 3.0 mol/(L·s). Which of the following statements is true?A) The rate of consumption of NH3is 2.0 mol/(L·s).B) The rate of consumption of O2is 2.0 mol/(L·s).C) The rate of formation of N2is 1.3 mol/(L·s).D) The rate of formation of N2is 2.0 mol/(L·s).E) The rate of consumption of NH3is 0.50 mol/(L·s).

Q: Which of the following is/are expected to affect the rate of a chemical reaction? 1) Increasing the reaction temperature. 2) Decreasing the reactant concentrations. 3) Doubling the volume of the reaction container. A) 1 only B) 2 only C) 3 only D) 1 and 2 E) 1, 2, and 3

Q: Which of the following conclusions concerning the concentration-time plot provided below is/are correct? 1) The concentration of substance D is decreasing over time. 2) The instantaneous reaction rate at point A is less than the instantaneous reaction rate at point B. 3) Substance D is a product of the reaction. A) 1 only B) 2 only C) 3 only D) 1 and 2 E) 1, 2, and 3

Q: Nitric oxide reacts with hydrogen at a measurable rate at 1000 K according to the following equation:2NO + 2H2 → N2+ 2H2OThe experimental rate law is Rate = k[NO]2[H2]. If time is measured in minutes and concentration is measured in moles per liter, what are the units for the rate of production of water?A) L2/(mol2·min).B) mol2/(L2·min).C) mol/(L·min).D) mol3/(L3·min).E) mol/(L2·min).

Q: How many mechanistic steps are depicted by in this potential energy diagram for the decomposition of cyclobutane to ethylene? A) two steps B) one step C) three steps D) four steps E) five steps

Q: Which of the following reactions is not an example of heterogeneous catalysis?A) CO(g) + 3H2(g) CH4(g) + H2O(g)B) C2H4(g) + H2(g) C2H6(g)C) 2CO(g) + 2NO(g) 2CO2(g) + N2(g)D) 2O3(g) 3O2(g)E) 2SO2(g) + O2(g) 2SO3(g)

Q: Which of the following reactions is not an example of homogeneous catalysis?A) 2O3(g) 3O2(g)B) S2O82-(aq) + 2I-(aq) 2SO42-(aq) + I2(aq)C) 2H2O2(aq) 2H2O(l) + O2(g)D) N2(g) + 3H2(g) 2NH3(g)E) CH3CO2CH3(aq) + H2O(l) CH3CO2H(aq) + CH3OH(aq)

Q: In a chemical reaction at constant temperature, the addition of a catalyst A) provides an alternative reaction pathway with a different activation energy. B) increases the concentration of the products at equilibrium. C) affects the equilibrium constant. D) increases the fraction of molecules with more than a given kinetic energy. E) decreases the energy released in the chemical reaction.

Q: The catalyzed pathway in a reaction mechanism has a __________ activation energy and thus causes a __________ reaction rate. A) higher, lower B) higher, higher C) higher, steady D) lower, higher E) lower, steady

Q: Which of the following statements is incorrect concerning a catalyst?A) A catalyst decreases the activation energy of a reaction.B) A catalyst may appear in the rate law for a reaction.C) A catalyst alters the equilibrium distribution of reactants and products.D) There is no net consumption of a catalyst in a reaction.E) A catalyst provides an alternative reaction mechanism.

Q: A suggested mechanism for the decomposition of ozone is O3 O2+ O fast equilibrium O + O3 2O2 slow step When the concentration of ozone is doubled and the concentration of oxygen is doubled, the instantaneous rate A) increases by a factor of 8. B) remains the same. C) increases by a factor of 4. D) decreases. E) increases by a factor of 2.

Q: The rate law for a reaction is found to be Rate = k[A]2[B]. Which of the following mechanisms gives this rate law?I. A + B E (fast)E + B → C + D (slow)II. A + B E (fast)E + A → C + D (slow)III. A + A → E (slow).E + B → C + D (fast)A) II onlyB) III onlyC) I onlyD) two of theseE) none of these

Q: A suggested mechanism for the decomposition of ozone is as follows:O3 O2+ O fast equilibriumO + O3 2O2 slow stepWhat is the rate law predicted by this mechanism?A) Rate = B) Rate = k2[O] [O3]C) Rate = D) Rate = E) Rate =

Q: Given the following fast equilibrium (below) proposed for the gas phase reaction between NO and O2, what is the expression for the equilibrium concentration of the intermediate NO3?NO + O2 NO3A) B) C) D) E)

Q: The reaction CHCl3(g) + Cl2(g) CCl4(g) + HCl(g) has been proposed to occur by the following mechanism. Cl2 2Cl fast equilibrium CHCl3+ Cl HCl + CCl3 slow step CCl3+ Cl CCl4 fast What is the rate law predicted by this mechanism? A) Rate = kexp[CHCl3][Cl2] B) Rate = k2[CHCl3][Cl] C) Rate = k1[Cl2] D) Rate = k3[CCl3][Cl] E) Rate = k2(k1/k-1)1/2[CHCl3][Cl2]1/2

Q: A mechanism that explains the rate law, Rate = k[(CH3)3CO2C(CH3)3], for the gas-phase thermal decomposition of di-tert-butyl peroxide is given below. For this proposed mechanism, the rate-determining step(s) must be A) step 1. B) step 3. C) step 2. D) step 1 + step 2 + step 3. E) 2 times step 2.

Q: The following mechanism has been suggested for the reaction between nitrogen monoxide and oxygen:NO(g) + NO(g) → N2O2(g) (slow)N2O2(g) + O2(g) → 2NO2(g) (fast)According to this mechanism, the experimental rate law isA) second-order in NO and first-order in O2.B) second-order in NO and zero-order in O2.C) first-order in NO and first-order in O2.D) first-order in NO and second-order in O2.E) first-order in NO and zero-order in O2.

Q: The acid-catalyzed reaction of acetone, CH3COCH3, with iodine can be represented by the equationCH3COCH3+ I2 CH2ICOCH3+ H++ I-It is found experimentally that the reaction is first-order with respect to both acetone and the hydrogen ion. The rate of the reaction is independent of the iodine concentration. Which of the following conclusions could be drawn from the experimental results?1) The uncatalyzed reaction would have a different pathway.2) Iodine is involved in the rate-determining step.3) The reaction takes place stepwise.A) 1 onlyB) 2 onlyC) 3 onlyD) 1 and 3E) 1, 2, and 3

Q: Below is a proposed mechanism for the decomposition of H2O2.H2O2+ I-→H2O + IO- slowH2O2+ IO-→H2O + O2+ I- fastWhich of the following statements is incorrect?A) IO-is a catalyst.B) I-is a catalyst.C) The net reaction is 2H2O2→2H2O + O2.D) The reaction is first-order with respect to [I-].E) The reaction is first-order with respect to [H2O2].

Q: The complete mechanism for a reaction is considered to occur in two steps, one of which is slow and the other fast:A + B → C + D slowA + C → E + F fastWhat is the net chemical equation predicted by this mechanism?A) 2A + B → D + E + FB) A + C → E + FC) A + B → D + E + FD) A + B → C + DE) A + B + C → D + E + F

Q: The complete mechanism for a reaction is considered to occur in two steps, one of which is slow and the other fast:A + 2B → C + D slowA + C → E + F fastWhat is the rate law predicted by this mechanism?A) Rate = k[A]2[B]B) Rate = k[A]2[B][C]C) Rate = k[A][C]D) Rate = k[A][B][C]E) Rate = k[A][B]2

Q: A proposed mechanism for the decomposition of N2O5 is as follows:N2O5 NO2+ NO3 slow stepNO2+ NO3 NO2+ O2+ NO fast stepNO + N2O5 3NO2 fast stepWhat is the rate law predicted by this mechanism?A) Rate = k1k2[N2O5][NO2][NO3]B) Rate = k2[NO2][NO3]C) Rate = k3[NO][N2O5]D) Rate = k1k2k3[N2O5]2E) Rate = k1[N2O5]

Q: Which of the following statements is incorrect? A) The slow step in a mechanism generally involves a three-body collision. B) After the addition of a catalyst, the collision rate between molecules is still the same. C) Most collisions between reactant molecules do not lead to a product. D) Chemical reactions involve collisions between the participating molecules. E) A three-body collision is less likely than a two-body collision.

Q: For the elementary reaction A + B → C + D, what is the predicted rate law?A) Rate = k[A]2B) Rate = k[A][B]C) Rate = kD) Rate = k[B]2E) Rate = k[A]/[C]

Q: Determine the molecularity of the following elementary reaction: O3→O2+ O.A) quadmolecularB) bimolecularC) unimolecularD) termolecularE) cannot be determined

Q: A possible mechanism for the gas phase reaction of NO and H2is as follows:Step 1 2NO N2O2Step 2 N2O2+ H2 N2O+ H2OStep 3 N2O + H2 N2+ H2OWhich of the following statements concerning this mechanism is not directly supported by the information provided?A) Step 1 is the rate determining step.B) N2O2 is an intermediate.C) There is no catalyst in this reaction.D) The rate expression for step 1 is rate = k[NO]2.E) All steps are bimolecular reactions.

Q: A proposed mechanism for the decomposition of N2O5 is as follows:N2O5 NO2+ NO3 slow stepNO2+ NO3 NO2+ O2+ NO fast stepNO + N2O5 3NO2 fast stepWhat is the overall chemical equation predicted by this mechanism?A) N2O5+ NO2+ NO3 → 4NO2+ O2B) N2O5+ NO →3NO2C) 2N2O5→4NO2+ O2D) N2O5→NO2+ NO3E) N2O5→NO2+ O2+ NO

Q: The decomposition of ozone may occur through the two-step mechanism shown below:step 1 O3 → O2+ Ostep 2 O3+ O → 2O2The oxygen atom is considered to be a(n)A) activated complex.B) catalyst.C) reaction intermediate.D) product.E) reactant.

Q: Which of the following statements is not a requirement for a valid reaction mechanism?A) Each elementary reaction must be bimolecular.B) There must not be net production of any intermediates.C) The elementary reactions of a mechanism must add up to the net chemical reaction.D) A mechanism must have only one rate-determining step.E) The rate law predicted by a mechanism must agree with the experimental rate law.

Q: The rate constant for a reaction at 40.0ºC is exactly 2 times that at 20.0ºC. Calculate the Arrhenius energy of activation for the reaction.A) 2.00 kJ/molB) 3.18 kJ/molC) 26.4 kJ/molD) 5.8 kJ/molE) none of these

Q: The Arrhenius equation, expresses the dependence of the rate constant on the reaction temperature. The slope of a plot of ln(k) versus 1/T is equal to A) B) C) D) E)

Q: For the first-order reactionN2O4(g) → NO2(g); Hº= 28.6 kJthe rate constant is k= 9.29 x 104 s-1 at -20ºC, and the activation energy is 53.7 kJ/mol. What is the rate constant at 21ºC?A) 1.08 x 105s-1B) 9.29 x 104s-1C) 1.74 x 105s-1D) 3.27 x 106s-1E) 4.94 x 104s-1

Q: The rate constants for the first-order decomposition of a compound are 6.19 x 10"4 s"1at 43ºC and 2.71 x 10"3s"1at 65ºC. What is the value of the activation energy for this reaction? (R=8.31J/(mol"¢K))A) 0.677 kJ/molB) 25.9 kJ/molC) 0.558 kJ/molD) 59.6kJ/molE) 1.56 kJ/mol

Q: The rate constant for a first-order reaction is 1.6 x 10-2 s-1 at 668 K and 5.1 x 10-2 s-1at 916K. What is the activation energy? (R=8.31J/(mol.K))A) 11 kJ/molB) 14 kJ/molC) 23 kJ/molD) 2900 kJ/molE) 24 kJ/mol

Q: For the first-order reactionN2O4(g) → NO2(g); Hº= 28.6 kJthe activation energy is 53.7 kJ/mol. What is the activation energy for the reverse reaction?A) 15.2 kJ/molB) 82.3 kJ/molC) -53.7 kJ/molD) 25.1 kJ/molE) 53.7 kJ/mol

Q: For the following reaction producing 1 mol of oxygen gas at a particular temperature, Hº=-200 kJ.NO(g) + O3(g) → NO2(g) + O2(g)The activation energy is 11 kJ/mol. What is the activation energy for the reverse reaction?A) 11 kJ/molB) 200 kJ/molC) 222 kJ/molD) 188 kJ/molE) 211 kJ/mol

Q: For the formation of 1 mol of nitrosyl chloride at a given temperature, H= -44 kJ.NO(g) + Cl2(g) → NOCl(g)The activation energy for this reaction is 59 kJ/mol. What is the activation energy for the reverse reaction?A) 59 kJ/molB) 15 kJ/molC) 103 kJ/molD) -44 kJ/molE) -103 kJ/mol

Q: Which of the following is not a postulate of collision theory? A) Reactant molecules must collide to react. B) Reactant molecules must collide with a certain minimum energy in order to form products. C) Reactant molecules must collide with the correct orientation in order to form products. D) The rate constant is directly proportional to the energy of activation. E) The maximum in the potential energy curve, the activation energy, is determined by the structure of the activated complex or transition state.

Q: The potential-energy diagram below describes the hypothetical reaction A + B → C + D. Assuming the y-axis label refers to the enthalpy(H) per mol, which of the following statements concerning this reaction coordinate is/are correct?1) The forward reaction is exothermic.2) The forward reaction rate is proportional to the change in enthalpy (H) of the forward reaction.3) Ea(forward) -Ea(reverse) is equal to the change in enthalpy (H) of the forward reaction.A) 1 onlyB) 2 onlyC) 3 onlyD) 1 and 3E) 1, 2, and 3

Q: The rates of most chemical reactions are sensitive to a change in the temperature of the reaction system. The increase in rate as the temperature increases is best explained by A) an increase in the collision frequency. B) an increase in the number of high-energy molecules. C) a decrease in the collision frequency. D) an increase in the activation energy. E) a decrease in the activation energy.

Q: When the concentrations of the reactants are increased, the rate of the reaction increases. This is best explained by A) an increase in the fraction of molecules that have enough energy to react. B) an increase in the rate constant. C) an increase in the average potential energy of the molecules. D) an increase in the frequency of the molecular collisions. E) an increase in the kinetic energy of the molecules.

Q: The main reason for the increase in reaction rate with temperature is that A) the fraction of high-energy molecules increases exponentially with temperature. B) the activation energy increases rapidly with temperature. C) a 10C temperature rise results in the rate doubling. D) there is a dramatic increase in the number of collisions. E) heat acts as a catalyst.

Q: What would happen if the kinetic energy of the reactants were not enough to provide the needed activation energy? A) The rate of the reaction would tend to increase. B) The reactants would continue to exist in their present form. C) The activated complex would be converted into products. D) The products would be produced at a lower energy state. E) The products would form at an unstable energy state.

Q: Which of the following changes will affect the activation energy of a reaction?1) Increasing or decreasing the reaction temperature.2) Adding a catalyst.3) Increasing or decreasing the reactant concentrations.A) 1 onlyB) 2 onlyC) 3 onlyD) 1 and 2E) 2 and 3

Q: For a solution containing only one solute dissolved in a solvent, we can calculate the mole fraction of the solvent directly, given only A) the molar mass of the solute. B) the density of the solution. C) the molar mass of the solvent. D) the mole fraction of the solute. E) the molarity of the solution.

Q: What is the molality of a solution that contains 8.16 g of glucose, C6H12O6, in 252.5g of water? A) 0.180 m B) 0.0453 m C) 0.00322 m D) 0.0114 m E) 0.0323 m