The rate consnt for a reaction is measured as a function of temperature. A plot of ln k versus 1/T is linear and has s slope of -1.01 x 1-^4K. Calculate the activation energy for the reaction

Answer : The activation energy for the reaction is,

Explanation :

According to the Arrhenius equation,

Taking logarithm on both side, we get:

where,

= activation energy for the reaction

R = gas constant = 8.314 J/mole.K

T = temperature

K = rate constant

A = pre-exponential factor

The linear equation expression is:

y = mx + c

Plot of ln (K) versus (1/T) gives a straight line with a slope is equal to,

As we are given that:

Slope =

So,

Thus, the activation energy for the reaction is,

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.

16

explanation:

the marks go by 4s