1.) molecules involved in a chemical reaction must collide to react. what is this concept called? .
a. collision theory
b. entropy.
c. enthalpy.
d. reaction rate.

2.) which of the following equations is used to describe reaction rates? .
a. ∆h t∆s.
b. ∆[reactant or product]/∆time
c. sproducts sreactants.
d. pv = nrt.