Question

Which statement concerning spontaneous chemical reactions is true?
a. Spontaneous chemical reactions always occur rapidly.
b. Spontaneous reactions are those that occur without an ongoing outside source of energy.
c. Spontaneous chemical reactions are those that occur with no change in energy.
d. A nonspontaneous reaction can be made spontaneous by the addition of a catalyst.

Answer 1

I believe the correct answer is b since a spontaneous reaction is self sufficient and should not need an ongoing out side source in order to proceed once it is started.  

a is false since some reactions that occur are relatively slow such as iron reacting with oxygen to make rust.

c is false since most reactions involve an energy change of some sort which is why we classify them as endothermic or exothermic.

d is false since catalysts help speed up reactions but do not really affect a the Gibbs free energy value which determines the spontaneity of the reaction.

Answer 2

Answer:

The answer is B

Explanation:

This is the answer