Chemical Kinetics

Question 1

the rate at which a chemical reaction occurs

Answer 1

Chemical Kinetics

Question 2

the minimum amount of energy to cause chemical reactions

Answer 2

Activation Energy

Question 3

3 factors that affect the rate of chemical reaction

Answer 3

1. concentration of reactants
2. temperature
3. presence of catalyst

Question 4

the mathematical relationship between the concentrations of the reactants, and the rate of reaction

Answer 4

Rate Law

Question 5

in A + B -> C + D

write the rate law expression

Answer 5

rate = K [A]^n [B]^m

Question 6

how to determine n and m in:

rate = K [A]^n [B]^m

Answer 6

only through experimentations

Question 7

Do you include the reactants and products in the rate law expression?

Answer 7

No, only the reactants are included

Question 8

What is the order of the following:

1.) rate = k [A] [B]
2.) rate = k [A]^2 [B]
3.) rate = k [A]^0
4.) rate = k [A]^2
5.) rate = k [A]

Answer 8

1. 2nd order
2. 3rd order
3. 0the order
4. 2nd order
5. 1st order

Question 9

Find the rate expression for the ff:

aA + bB -> cC + dD

Answer 9

• 1/a Δ[A] / Δt =
• 1/b Δ[B] / Δt =
  1/c Δ[C] / Δt =
  1/d Δ[D] / Δt

Question 10

In writing rate expressions, why is the reactants side NEGATIVE, and the products side POSITIVE?

Answer 10

Negative si reactants kasi nababawasan sila to create more products

Question 11

MOST important thing to remember before writing rate expressions?

Answer 11

BALANCE THE EQ

Question 12

Are solids and liquids included in the rate expressions?

Answer 12

No, only gas and aq

Question 13

Differential Rate Law vs Integrated Rate Law

Answer 13

DRL: express how rate depends on concentration
(rate = K [A]^n [B]^m)

IRL: how concentrations depend on time (yung 3 equations based on y=mx+b)

Question 14

If rate is multiplied by the ff., what is the reaction order?

1
2
4
1/2

Answer 14

0th
1st
2nd
-1st

Question 15

the time required for one-half of a reactant to react

Answer 15

half-life

Question 16

In half-life, [A]t is = to?

Answer 16

0.5 [A]0

Question 17

Write the INTEGRATED RATE LAW and HALF LIFE equations of the following rate laws

rate = k
rate = k [A]
rate = k [A]^2

Answer 17

0th order:

[A]t = -kt + [A]0
t 1/2 = [A]0 / 2k

1st order:
ln[A]t = -kt + [A]0
t 1/2 = ln2 / k

2nd order:
1/[A]t = kt + 1/[A]0
t 1/1 = 1 / k[A]0

Question 18

How to know what order a reaction is based from a given table (Time in s & Concentration in M)

Answer 18

Kung anong r (linearity constant) ang closer to |1|

Question 19

In regression calculator, what will you put in x and y axis in figuring out the reaction order?

Answer 19

0th order:
x-axis = time
y-axis = [A]

1st order:
x-axis = time
y-axis = ln [A]

2nd order:
x-axis = time
y-axis = 1/ [A]

Question 20

What is the meaning of

r
A
B

in regression

Answer 20

r = linearity regression

A = y-intercept (b in y = mx + b)

B = slope/rate constant k (m in y = mx + b)

Question 21

If the value of B is negative, will the rate constant k be negative also?

Answer 21

No

the slope CAN BE negative, but k CANNOT be

Question 22

What are the units of K per reaction order?

Answer 22

0th order = M/s
1st order = 1/s
2nd order = 1/M s

Question 23

What order does the rate of radioactive decay follow?

Answer 23

first order kinetics

Question 24

What is the formula for the % of radioactive decay after t days

Answer 24

Nt/N0 x 100

Question 25

What does the collision theory state?

Answer 25

For a chemical reaction to take place, the particles must collide effectively

Question 26

According to the Collision Theory, what is the relationship between the ff:

1. rate of reaction
2. frequency of collision

Answer 26

direct relationship

Question 27

What is the formula of the reaction rate according to the collision theory?

Answer 27

Reaction Rate = # of collisions/time

Question 28

2 Factors that determine an effective collision

Answer 28

1. energy of colliding particles
2. orientation of particles

Question 29

What are formed by reactants as a result of collision?

Answer 29

temporary species

Question 30

What should be overcome to produce a chemical reaction?

Answer 30

threshold energy (activation energy)

Question 31

What does the ARRHENIUS EQUATION describe?

Answer 31

describes the temperature dependence of the rate constant

Question 32

3 equations in Arrhenius Equation

Answer 32

ln k = - Ea / RT + ln A

k = A e ^ (- Ea / RT)

A = k e ^ (Ea / RT)

wherein:
Ea is J/mol
A is collision frequency
R is 8.314 J / mol k
T is temperature in K

Question 33

In regression calculator, what will you put in x and y axis in arrhenius equation?

Answer 33

x - axis = 1/Temperature
y - axis = ln [k]

Question 34

In arrhenius equation, how to get Ea and A

Answer 34

Ea = -slope x R

A = e^(y-intercept)