Which of the following is necessary to increase the rate of a reaction? a. a decrease in the frequency of collisions b. an increase in the frequency of collisions c. a decrease in the frequency of successful collisions d. an increase in the frequency of successful collisions

To increase the rate of a reaction, D. an increase in the frequency of successful collisions is necessary. As the collision that are successful, that is molecules collide with energy that is sufficient to break a chemical bond or that collide with proper orientation that can only increase the rate of the reaction.

So the answer is  D. an increase in the frequency of successful collisions is necessary

n2(g) + 3h2-> 2nh3(g)   this is the balanced equation

note the mole ratio between n2, h2 and nh3.   it is 1 : 3 : 2   this will be important.

moles n2 present = 28.0 g n2 x 1 mole n2/28 g = 1 mole n2 present

moles h2 present = 25.0 g h2 x 1 mole h2/2 g = 12.5 moles h2 present

based on mole ratio, n2 is limiting in this situation because there is more than enough h2 but not enough n2.

moles nh3 that can be produced = 1 mole n2 x 2 moles nh3/mole n2 = 2 moles nh3 can be produced

grams of nh3 that can be produced = 2 moles nh3 x 17 g/mole = 34 grams of nh3 can be produced

note:   the key to this problem is recognizing that n2 is limiting, and therefore limits how much nh3 can be produced.

b. is the answer hoped i