Exam 2

Question 1

H2(g) + I2(g) to 2HI(g)

Answer 1

Rate of reactant: negative
Rate of I2/H2=-0.015 m/s …“for every second, 0.015 m of I2 and H2 are lost
Rate of HI= (0.90M-0.00M)/30s = 0.03 m/s
Rate of product: positive

Question 2

Units on Rate Law

Answer 2

Rate rxn: m/s
K: rate law constant, depends on the order!
A: Concentration
x: “order”

Question 3

If x=0 meaning zero order in A

Answer 3

A and Rate Rxn are independent of each other

Question 4

If x=1 meaning first order in A

Answer 4

Rate rxn is directly related to A

Question 5

If x=2 meaning second order in A

Answer 5

Rate rxn is squared relationship with A

Question 6

If there is more than one reactant… (A+B to products)

Answer 6

First order in A, second order in B… THIRD ORDER OVERALL, overrall stoichiometry can NOT be used for order

Question 7

K value is dependent on, but x is not

Answer 7

Temperature

Question 8

Zero order reaction equation

Answer 8

A(t)= concentration at the time
K=rate law constant
t=time
A=initial concentration

(A)t= -Kt + (A)0

Question 9

Graph of (a) vs. t , if linear zero order

Answer 9

k: -slope

Question 10

Graph of ln (a) vs t, if linear first order

Answer 10

k: -slope

Question 11

Graph of 1/(A) vs. t… if linear second order

Answer 11

k: slope

Question 12

Determine rate law including value and limits of K

Answer 12

Find the r^2 closest to 1

Question 13

Overall order units

Answer 13

0= ms^-1
1 = s^-1
2 = m^-1 s^-1
3 = m^-2 s^-1

Question 14

Half life equations

Answer 14

Zero order T(1/2) = A0/2K
First order T(1/2) = 0.693/K
Second order T(1/2) = 1/K(A)0

Question 15

Trends

Answer 15

0 order -
1st order - 1/2 lives shorter
2nd order - 1/2 lives longer

Question 16

Formula for activation energy

Answer 16

K = Ae ((-Ta)/(Rt)) 
K - rate constant
A - Arrhenius constant
-TA - activation energy
R - 8.312 J/ mol k 
K - temperature

-

Question 17

Trends

Answer 17

larger Ea … slower rates, smaller K
Larger temp. … faster rate, longer K
Larger A … frequency factor ( orientation ) faster reaction, larger K values

Question 18

points

Answer 18

-EA/R - slope
ln A - y intercept

lnk = -EA/R (1/t) +lna

Question 19

collision by collision mentality

Answer 19

how much energy in collision orientation in energy