DAT Destroyer Gen Chem question 154

[IsaacYankem]

A catalyst will change?

A. The reaction mechanism
B. The energy of activation
C. The specific rate constant
D. Two of the above
E. All of the above.

Obviously B is correct, I remember Chad saying that enzymes will often use a different reaction mechanism or route to get to the lower Ea (his example of going from Phoenix to Tucson via the South Pole), but C? I can't seem to rationalize why C is correct.

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[ekephant]

A catalyst will increase the rate of reaction. Remember the equation for the rate = k[A] where k is the specific rate constant. Also remember that catalysts will not change the concentrations of the reactants [A] or ; therefore the only way it can increase the rate is by increasing the rate constant k.

 

[NewBee12]

A catalyst will lower the energy of activation ...thus speed up a reaction. The rate constant is directly related to the activation energy by the Arrhenius equation. Hope this helps
Good luck

 

[spoog74]

A catalyst will change?

A. The reaction mechanism
B. The energy of activation
C. The specific rate constant
D. Two of the above
E. All of the above.

Obviously B is correct, I remember Chad saying that enzymes will often use a different reaction mechanism or route to get to the lower Ea (his example of going from Phoenix to Tucson via the South Pole), but C? I can't seem to rationalize why C is correct.

i think you're confused with equilibrium constant K and specific rate constant. Dont worry about that. THE DAT would never ask something like this> They usually ask something like a catalyst will change :

Mechanism of reaction

Something like that. Dont worry

 

[biomolecmed]

Yes. Since catalyst is used, it will lowerthe activation energy, therefore change the rate constant, k. Destroyer is correct. Chad's videos were kind of of the mark here. Hope this helps. Good luck.