AP Chemistry Units 4, 5, 6

SNAP

Sodium (NA), Nitrate (NO3), Ammonium (NH4), Potassium (K) are always soluble

When doing stoichometry, never forget..

the limiting reactant

Percent error equation

actual-theoretical/theoretical

Oxidation

Loses Electrons

Reduction

Gains Electrons

amphoteric

substance that can act as both an acid and a base

To find rate orders..

find where concentrations are constant, check for double/triple/quadruaple. Set it up by putting x with the power of two = the amount it multipled by.

Zero order reaction

The graph is a straight line equal to -k and concentration vs. time.

First order reaction

The graph is the natural log of [A] vs. Time. This creates a straight line with a slope of -k and y-interest of ln[A] at time 0.

Second order reaction

The inverse concentrations vs. time create a straight line, where the slope is k and y-intercept is (1/[A]) at time zero

Half life equation

For first order reactions, the half-life is constant and is given by the equation t1/2 = 0.693/k.

Collision Theory

Collision theory states reactions only occur when chemicals collide with each other with sufficient energy (activation energy).

They can react more..

if there's a higher concentration of aqueous or gaseous

substances, or a high surface area of a solid substance.

Molecules will only react if they collide

with the correct orientation.

Where is activation energy on a graph?

Activation energy is represented as the peak of the energy barrier that reactants must overcome during a chemical reaction on an energy vs. reaction coordinate graph.

Intermediate

formed and then consumed

Catalyst

a substance that increases the rate of a chemical reaction by lowering the activation energy without being consumed in the process. consumed and then formed

unimolecular

reaction involving a single reactant molecule that undergoes a change in structure or composition.

slow step is the

rate determining step

if the slow step has an intermediate

replace it by using other steps

The reaction rate is written with the

reactants (not products)

In a multistep energy diagram, the highest peak

is the slowest step

first law of thermodynamics

states that energy cannot be created or destroyed, only transformed from one form to another.

Enthalpy

Change in H, positive is endo, negative is exo

Entropy

Change in S

specific heat

of substance is how much heat is required to raise one gram of a substance by one degree celsius (or one degree kelvin)