Consider the following reaction:

2NO(g)+O2(g)-->2 NO2(g)+ energy

if the number of moles of oxygen is increased to two moles, the

a. reaction speeds up
b. reaction slows down
c. temperature increases
d. temperature decreases

2 answers

If you add excess oxygen, the chance for a random proximate collision between an NO and O2 molecule is increased, so the a) is true. This is especially true if the reaction was in a closed container.
Thank-you