Chemical Kinetics Quiz

The reaction OH−(aq) + H+(aq) → H2O(l) is an elementary reaction. The rate law for this reaction is:

• Rate = k

• Rate = k [OH−] [H+]

• Rate = k [OH−]2

• Rate = k [H+]2

• can’t be determined from the information provided

For the following elementary reaction: NO3 + CO  NO2 + CO2 The molecularity of the reaction is __________, and the rate law is __________.

• 4 , rate = k [NO3] [CO] [NO2] [CO2]

• 2 , rate = k [NO3] [CO] / [NO2] [CO2]

• 4 , rate = k [NO2] [CO2] / [NO3] [CO]

• 2 , rate = k [NO2] [CO2]

• 2 , rate = k [NO3] [CO]

What are the units of k for the rate law: Rate = k[A][B], when the concentration unit is mol/L?

• s–1

• s

• L mol-1 s–1

• L2 mol–2 s–1

• L2 s2 mol–2

A reaction has the following stoichiometry: H2 + 2 ICl → I2 + 2 HCl Which of the following would be a correct definition of the average rate of reaction?

• Rate = +∆[H2]/ ∆t

• Rate = +∆[HCl]/ ∆t

• Rate = – ∆[ICl]/ ∆t

• Rate = +(1/2) ∆[[HCl]/∆t

• All of these are correct

Consider the rate law: rate = k[Y]m[Z]n. How are the exponents m and n determined?

• by using the balanced chemical equation

• by using the subscripts of the chemical formulas

• by using the coefficients of the chemical formulas

• by educated guess

• by experiment

What is the rate constant for a first order reaction A → B given the following data: Time (sec) 0 6 12 18 [A] 1.76 0.88 0.44 0.22

• 0.231

• 1.0

• 0.171

• 0.116

• Cannot be determined

The following rate data were obtained at 0oC for the following reaction. What is the rate-law expression for this reaction: 2 ClO2 + 2OH- ClO3- + ClO2- + H2O

• rate = k[ClO2]

• rate = k[ClO2]2[HO-]2

• rate = k[ClO2]2[HO-]

• rate = k[ClO2][HO-]

• rate = k[ClO2][HO-]2

The integrated rate law of a first order reaction is :

• Pt – P0 = – kt

• Pt – P0 = – kt(RT)

• Ln Pt – ln Po = -kt

• Ln Pt – ln P0 = -kt(RT)

• 1/( Pt) – 1/( Po) = kt/(RT)

What is the unit of a reaction rate for a first order reaction?

• mol L–1 sec

• sec–1

• L mol–1 sec–1

• mol L–1 sec–1

• mol2 L–2 sec1

A catalyst will change the ______ of the reaction.

• activation energy

• enthalpy

• entropy

• free energy