Easy chem I know just need help?

Question

Briefly comment on the effect of a catalyst on each of the following.
(a) activation energy
A catalyst does not change the activation energy.
A catalyst raises the activation energy by changing the rate.
A catalyst lowers the activation energy by changing the rate.
A catalyst lowers the activation energy by changing the reaction mechanism.
A catalyst raises the activation energy by changing the reaction mechanism.

(b) reaction mechanism
A catalyst always makes a reaction mechanim more complicated.
A catalyst always simplifies a reaction mechanim.
A catalyst changes the reaction mechanism.
A catalyst does not change the reaction mechanism.

(c) enthalpy of reaction
A catalyst does not change the enthalpy of of reaction.
A catalyst changes the enthalpy of reaction, either raising or lowering it.
A catalyst always lowers the enthalpy of reaction.
A catalyst always raises the enthalpy of reaction.

Answer 1

A)
A catalyst lowers the activation energy by changing the rate.

B)
A catalyst does not change the reaction mechanism.

C)
A catalyst does not change the enthalpy of of reaction.

Answer 2

a) A catalyst changes lowers the activation energy by changing the mechanism.

b) A catalyst changes the reaction mechanism in theory (they thing that the catalyst gives a surface for the reaction to occur on)

c) No change on enthalpy.

Answer 3

(a) the third one.

(b) the last one

(C) the first one.

Answer 4

blah blah blah do your own homework kiddo