Review for Chem final

Bond forming

releases energy (exothermic)

Bond breaking

endothermic (requires energy)

Spontaneous

\-ΔG, Decreasing the amount of available energy to perform work, happens naturally or without effort

Nonspontaneous

ΔG, Increasing the amount of available energy to preform work, does not happen naturally or with effort

Enthalpy

A measure of heat in a system

Entropy

How much energy is spread out

ΔH

Enthalpy

ΔS

Entropy

ΔG

Gibb's Free Energy

How does adding a catalyst affect the rate of reaction?

It lowers the activation energy

+ΔS

Increasing entropy/energy spreads out

The change in entropy

ΔS

heat of formation equation

sum of products - sum f products

How does lowering the temperature affect a reactions rate?

The reaction gets slower

How does decreasing the concentration of the reactants affect a reactions rate?

The reaction will increase

Q\=mc∆T

specific heat formula

∆G=∆H-T∆S

Gibb’s free energy equation

Activation energy

the minimum amount of energy required to start a chemical reaction

Activated complex

The state of the particles that is in between the reactants and products

Does the potential energy graph slope up or down in an endothermic reaction?

Up

Does the potential energy graph slope up or down in an exothermic reaction?

Up a little bit an then down a lot

Heat formation is defined as

The amount of heat absorbed

Convection

A cyclic heat transfer in a liquid or solid

Conduction

Heat is transferred between 2 objects that are in contact

Radiation

Heat transfer without something touching

1st law of thermodynamics

Energy cannot be created or destroyed

What happens to the entropy of a solid to a liquid

Get bigger(more randomness)

What happens to the entropy of a gas to a solid

Gets smaller(less randomness)

What is equilibrium?

When the forward reactions equal the rate of the reverse reactions. The concentrations of its products and reactants will remain unchanged.

What does K mean?

The equilibrium constant

K>>1

The reaction if product-favored

K<

The reaction is reactant-favored

K=1

The reaction favors neither.

LE CHATELIER’S PRINCIPLE

If an equilibrium is stressed, the equilibrium shifts in the direction that relieves the stress.

What does not stress a system?

Catalysts and nobel gases

What is a Reaction Quotient(Q)?

Describes the concentrations of a system to compare to the equilibrium constant (Kc) to determine if the system is at equilibrium.

Q>K

then the reaction has more products than reactants, so we shift to the left! (Create more reactants)

Q=K

then the reaction is at equilibrium!

Q

then the reaction has more reactants than products, so we shift to the right! (Create more products)

what is this?

Reaction Quotient equation

What happens when you increase the concentration of the reactants?

shift the equilibrium to the right (more product is created).

What happens when you increase the concentration of the products?

shift the equilibrium to the left (more products dissociate into reactants)

What happens when you decrease the concentration of the reactants?

shift the equilibrium to the left (less reactants to create products, so more products dissociate into reactants).

What happens when you decrease the concentration of the products?

shift the equilibrium to the right (less products dissociate into reactants, so more reactants create products)

What happens when you increase the pressure of a system?

the concentration of the molecules to increase on the side with more moles on it. Equilibrium shifts in the opposite direction.

What happens when you decrease the pressure of a system?

Decreasing the pressure decreases the concentration of the side with more moles on it. equilibrium shifts in the opposite direction

What happens when you increase the temperature in an exothermic reaction?

By increasing the heat, more AB products will be destroyed, shifting equilibrium to the left.

What happens when you decrease the temperature in an exothermic reaction?

By decreasing the heat, more AB products will be created, shifting equilibrium to the right.

What happens when you increase the temperature in an endothermic reaction?

By increasing the heat, more AB products will be destroyed, shifting equilibrium to the right.

What happens when you decrease the temperature in an endothermic reaction?

By decreasing the heat, more AB products will be created, shifting equilibrium to the left.

What is a solid?

Definitive shape and volume.

What is a liquid?

Indefinite shape, but definite volume.

What is a gas?

Indefinite shape and indefinite volume.

What is plasma?

Gas with free flowing electrons

Temperature is…

Temperature is the measure of the average kinetic energy of the molecules in a substance.

What is melting?

Changing from solid to liquid

What is vaporization?

Changing from liquid to gas

What is condensation?

Changing from gas to liquid

What is freezing?

Changing from liquid to solid

What is sublimation?

Changing from solid to gas

What is deposition?

Changing from gas to solid

What are IMF’s?

are forces of attraction or repulsion between two molecules.

Ion-diploe

strongest IMF, metal and non-metal, polar and non-polar

Hydrogen Bonding

Hydrogen bonding is an attractive force that takes place between hydrogen atoms attached to ONLY Nitrogen, Oxygen, & Fluorine (NOF).

Diploe-Diploe

Dipole-dipole IMFs take place between two polar molecules. Any molecules that are polar have dipole-dipole between them.

LDF

All bonds are this, are weak partial attractions between two polar or nonpolar molecules

What is evaporation?

is the process of liquid molecules becoming gaseous at any temperature.

Does temperature change in a phase change?

NO!!!!

What is Triple Point?

Pressure and temperature at which the substance exists as all the states of matter

What is Critical Point?

Pressure and temperature when the compound becomes a supercritical fluid (fluid-gas hybrid)

Molarity equation

Molarity=moles/liters of solution(l)

What is diluting?

To dilute a liquid, means to make it less concentrated of a certain substance. This process is used to create a desired concentration from a substance.

Dilutions equation

M1V1=M2V2

What are COLLIGATIVE PROPERTIEs

Substances dissolve differently depending on the solute and solvent.

Like Dissolves Like

Polar molecules dissolve polar molecules, nonpolar molecules dissolve nonpolar molecules.

Soluble

Solid will dissolve

Insoluble

Solid will not dissolve

Miscible

Liquid will mix

Immiscible

Liquid will not mix

Unsaturated

More solute can be added to the mixture or the temperature can be decreased. No particles.(under the line)

Saturated

The exact amount of temperature and particles, so that no more particles can be dissolved.

Supersaturated

More solute exists in the solution than can be dissolved. Particles are present.

Daltons Law

Boyle’s Law

Charle’s Law

Gay-lussac’s law

Avogadro’s law

Combined Gas Law

Ideal gas law equation

Moles at STP equal?

22\.4L

What is stoichiometry?

is the process of analyzing and calculating mass relationships in chemical reactions.

What is a limiting reactant?

the reactant that gets used up first in a chemical reactant

What is theoretical yield?

is the maximum amount of product that can be generated from a chemical reaction. Theoretically, all of the reactant will be used to create as much product as possible.

What is actual yield?

is the amount of product that is ACTUALLY generated during a chemical reaction.

What is percent yield?

The percent yield is the percentage of product that was actually created compared to what could theoretically be created.

How do you find percent yield?

Actual/Theoretical ᐧ 100 = % Yield

What is excess reactant?

the reactants that are not used up when the reaction is finished

Amphoteric

1. (of a compound, especially a metal oxide or hydroxide) able to react both as a base and as an acid.

What is fission?

Fission occurs when a neutron hits a large, unstable nucleus and causes it to break into two smaller nuclei.

What is critical mass?

is the amount of a substance that must be present in order for a chain reaction to occur.