Mid Term

Question 1

Disappearance Rate

Answer 1

Reaction rate for a reactant since reactants are being consumed.

Question 1

Rate of reaction (Reaction Rate) and units

Answer 1

Change of amount of reactant or product per unit time

M/t or mol/L*t

Question 2

Appearance Rate

Answer 2

Reatction rate of a product since products are being created.

Question 3

Relative Reaction Rate (used when?)

Answer 3

When we want to know the rate of reaction (reaction rate) of one reactant or product given another.

Question 4

aA + bB –> cC + dD (Relative Reaction rate expression)

Answer 4

-1/a delta[A]/delta[t] = -1/b delta[B]/delta[t] = 1/c delta[C]/delta[t] = 1/d delta[D]/delta[t]

Question 5

Factors that increase the rate of reaction (and how it relates to collision theory).

Answer 5

1. Nature of reactants
2. Concentrations
3. Temperature
4. Surface area
5. Presence of catalyst

Question 6

Why does surface area increase the rate of reaction?

Answer 6

Increasing the surface area gives the reactant more locations at which to react, thus increasing the reaction rate.

Question 7

Rate Laws (def)

Answer 7

Mathematical expressions that describe the relationship between the rate of a reaction of a chemical reaction and the concentration of its reactants.

Question 8

Rate Law Equation

Answer 8

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

Question 9

Chemical Kinetics

Answer 9

Study of how fast chemical reactions proceed from reactants to products.

Question 10

Initial Rate of reaction

Answer 10

Instantaneous rate at the start of a chemical reaction

Question 11

Rate Law

Answer 11

Mathamatical expression that describes the relationship between the reaction rate of a chemical reaction and the concentration of its reactant

Rate = k[A]^x[B]^y

Question 11

Reaction Order

Answer 11

How concentration affects the reaction rate.

Question 11

Zero Order Reaction

Answer 11

The concentration doesn’t affect the reaction rate.

Rate = k

Question 12

1st Order

Answer 12

Concentration affects the reaction rate

Rate = k[A]^1

Question 13

2nd Order

Answer 13

Concentration greatly affects the reaction rate.

Rate = [A]^2

Question 14

What does tripling the concentration do the reaction rate in regards to zero, 1st, and second order reactions?

Answer 14

Zero - No affect 3^0 (concentration) = 1(rate)

1st - triples 3^1 (concentration) = 3 rate

2nd - increase by a factor nine. 3^2 (concentration) = 9 reaction rate.

Question 15

K constant

Answer 15

Tells us how fast the reaction is going.

(the higher the k constant the faster the reaction)

Question 16

Rate constant units based on order numbers (zero, first, and second). (Two units for each might be on the test)

Answer 16

Zero = M^1 t^-1 or M/t
1st = M^0 t^-1 or t^-1 or 1/t
2nd = M^-1 t^-1 or 1/M*t

Question 17

Units for reaction rate and rate constants (based on the reaction order) formula

Answer 17

M^1-n t^-1

n = reaction order or overall reaction order

Question 18

Evaluate experimental data to determine reaction orders, rate constants, and overall rate laws for given reactions. (steps and how to solve for k)

Answer 18

1. Choose trial in which only one of the reactant changes.
2. Find the changes in concentrations and initial rates of those trials.
3. Set up concentration change to the x power = change in rate.
4. Solve for x to find reaction order.
5. Plug in the concentrations and rate from one trial into the update rate law to solve for k.

Question 19

How to determine which trial to use when solving for rate constant? (Put in answer from professor)

Question 20

Rate of reaction (Reaction Rate) unit

Answer 20

M/t

Question 21

Determine the rate law (find what)?

Answer 21

Find reaction orders

Question 22

Collision Theory

Answer 22

For particles to react they must collide together with sufficient energy.

Question 23

Rate of reaction (depends on what)? (two things)

Answer 23

1. Frequency of collisions
2. Amount of energy the particles have
   -more energy they can transfer during
   collisions.

Question 24

Integrated Rate Law Def

Answer 24

Second form of each rate law that relates the concentrations of reactants and time

Question 25

Integrated Rate Law Equations (zero, 1st, 2nd order).

Answer 25

Zero: [A]t = [A]o - kt
1st: ln[A]t = ln[A]o - kt
2nd: 1/[A]t = 1/[A]o + kt

[A]t means concentration at some time.

Question 26

Arrenius Equation

Answer 26

Mathematical expression that relates rate constant, activation energy and temperature together.

Can take multiple formats.

Question 27

Ea Unit

Answer 27

J/mol or kJ/mol (depends on what they ask)