Catalyst Questions (Chemistry)?

Question

True or false, and explain please.

A catalyst causes a reaction rate to increase by lowering the total amount of energy produced.

The larger surface area to volume ratio, the higher the reaction rate for chemical reactions.

Thanks for any help!

Answer 1

The first one is false. A catalyst increases the reaction rate by lower the amount of activation energy needed for the reaction. The total amount of energy produced will be the same.

The second one is true. When you have a higher amount of surface area, there are a greater number of surface sites available for reaction (the reaction can only occur on the outside of the material, not the inner parts). So, more surface area means that there is effectively a higher concentration of that chemical, giving a faster reaction.

Answer 2

1. False. A catalyst lowers the activation energy for a chemical reaction to occur by providing an alternative reaction mechanism. By doing this, the number of molecules with energies equal to or higher than the activation energy will increase, thus increasing the frequency of effective collisions and the higher the rate of reaction.

2. True. The larger the surface to volume ratio, the higher the frequency of collision between the reactant molecules. The higher the frequency of collisions, the higher the frequency of effective collisions and the higher the rate of reaction.

Answer 3

False

True

Answer 4

a. enable an alternate path for the reaction that has a lower activation barrier.