Chemistry Chapter 12 - Part 1

What are the 4 factors that affect the rate of a reaction?

1. Temperature

2. Concentration of Reactants

3. Presence of a catalyst

4. Surface Area of Reactants

What are the 2 ways of looking at a reaction (A —> B)

1. Formation (of B)

2. Decomposition (of A)

What is Rate in terms of concentration and time?

change in concentration / change in time

What is the initial rate?

the rate at the starting point of the reaction

What is instantaneous rate?

the rate at a specific point

Can rate change?

yes

What is the reaction rate for the reaction A —> B =?

(Δ[A]/ΔT)*-1/a (decomposition of reactants)

or

(Δ[B]/ΔT)*1/b (formation of products)

What is the equation for general rate law?

Rate=k[A]^m[B]ⁿ… where A and B are the reactants and m and n are the rate orders that must be determined experimentally.

What is the overall reaction order equal to?

the sum of the individual rate orders (m + n + …)

How can you use experimental trials to determine the rate law?

1. If you double the concentration of one component and keep the others constant and the rate doubles, it is a 1st order reaction.

2. If you double the concentration of one component and keep the others constant and the rate increases by 4x, it is a 2nd order reaction.

What are integrated rate laws?

method used to derive a linear equation to plot data and determine the reaction order (zero, 1st, 2nd, or 3rd)

What does a zero order reaction mean?

changes in concentrations do not affect the rate.

What is the integrated rate law for zero order reactions?

[A]_t - [A]₀ = -kt

What is the half life = in a zero order reaction?

t_1/2=[((1/2)[A]₀)/k]

What graph axis’ makes a linear line for a zero order equation

x = time, y = [A]

What is the integrated rate law for 1st order reactions?

ln[A]_t - ln[A]₀ = -kt

What is the half life = in 1st order reactions?

t_1/2=[(-ln(1/2))/k] or [0.693/k]

What graph axis’ makes a linear line for a 1st order equation

x=t, y=ln[A]

What is the 2nd order integrated rate law?

[1/[A]_t] = kt + (1/[A]₀)

What is the half life of second order reactions =?

t_1/2 = 1/k[A]₀

What graph axis’ makes a linear line for a 2nd order equation

x=t, y=1/[A]_t

What are the 3 primary forms of radioactive emission?

1. Alpha emissions

2. Beta emissions

3. Gamma Emissions

What represents Alpha emissions?

^4₂He

What are alpha emissions?

helium with extra energy

What represents beta emissions?

^0_-1e

What are beta emissions?

electron with energy

What represents gamma emissions?

⁰₀γ

What are gamma emissions?

powerful, high energy wavelength, most are dangerous

What are the factors with temperature and rate that allow a reaction to occur?

1. The collision model

2. The orientation factor

3. Arrhenins

What is the collision model?

where molecules, ions, or other atoms involved in a kinetic reaction must 1st collide

What is the orientation factor

The molecules colliding must have the correct orientation needed for the initial reaction

What is the Arrhenins?

molecules must possess a minimum amount of energy to react.

What is this minimum amount of energy needed for a reaction called?

Activation energy (Ea)

As temperature increases, what happens to the amount of molecules with the necessary activation energy

it increases, more molecules have enough activation energy needed to react.