chem test 2

solute

solution that consists of a smaller quantity of one substance

solvent

solute is dissolved in a larger quantity of solvent. in aqueous solutions, water serves as the solvent`

why is water a good solvent

polar molecule, strongly interacts with substances, very electronegative. unequal distribution of electrons, making it partially pos and neg (polar)

electronegativity

ability to attract shared electrons

conducting electricity in solutions

pure water and pure ionic solids cant conduct electricity . but in a mixed dissolved solution, electricity is conducted through freed ions

electrolytes

substance that conducts electricity when dissolved in water

strong electrolytes

completely dissociates into ions

weak electrolytes

partially dissociate into ions. most of the electrolyte remains

nonelectrolytes

do not create ions

molarity

mols solute/L solution

dilution equation

m1v1=m2v2

concentrated solution

more solute particles are present per unit volume

dilute solution

same number of solute particles are present, but less solute particles per unit volume

molecular equations

show all reactants and products as if they were intact, undissociated compounds

total ionic equation

shows all soluble ionic substances dissociated into ions

spectator ions

not involved in the actual chemical change

precipitation rxns + other names

aka metathesis or double displacement. two soluble ionic compounds react to form an insoluble product. more than one precipate can form

acid

substance that provides H+ ions when dissolved in water, aka proton donor

base

substance that produces OH- ions when dissolved in water. aka proton acceptor

acid base rxn name

aka neutralizaiton reaction

what gives off gaseous product

HCO_3, CO₃, SO₃

titration

base is added to acid until they are equal

equivalent point

mol of H+ from acid = mol of OH- product by base

end point

when there is slight excess of base and indicator changes color permanently

net ionic equation

DIVIDE BY THE GREATEST COMMON FACTOR!

oxidation

loss of electrons

reduction

gain of electrons

oxidizing agent

gains electrons and is reduced

reducing agent

loses electrons and is oxidized

on molecule in elemental form

0

on monoatomic ion

ion charge. ex Na+ is 1

on group 1a

+1

on 2a

+2

on hydrogen

+1 with nonmetals, -1 with metals

on fluorine

-1

on oxygen

-1 in peroxides, -2 with everything else

on group 7a

-1 with metals, nonmetals, and halogens

equilibrium reactions

rate of creating product vs converting back into reactant is equal

bronstead lowry

proton donor/acceptor

arrhenius

increase of H+ or OH-

asking for how many g of solute is in something and gives the molarity

use the molar mass. the entire thing is the solute

how are gases different from other substances

greatly affected by pressure

gas when heated

expands, 50-100x larger

gases mixing

can form a solution and mix in any proportions. unlike liquids, ex oil and water

pressure equation

force/area

atmospheric pressure

comes from atmospheric gases on earth surface. decreases with altitude

standard pressure in a barometer or manometer

760

higher pressure in a barometer

higher mercury reading

manometer

mercury goes toward the lower pressure.

manometer higher on the right (atmosphere side)

higher pressure is the gas. atm + pressure of the gas

manometer higher on the left (gas side)

pressure of atmosphere is higher. atm-pressure of the gas

ideal gas relationships

linear relationships between pvnt

charles law

V∝T or V/T= constant

boyles law

V∝1/P or PV=constant or P1V1=P2V2

gas laws measurements

kelvin, liters

avogadros law

at fixed temp and pressure, equal volumes of any ideal gas contain equal number of particles or moles

stp

1 atm and 0 degrees c

standard molar volume

volume of 1 mol of an ideal gas at stp. even though they have different molar masses, they have the same number of particles. 22.4L

what does kinetic molecular theory describe

ideal gases

kmt

gas has a volume of 0, constant random straight line motion except for collisions, dont lose any energy during collisions and have no attractice/repulsive forces

at ordinary pressure

free volume =volume of container. volume of gas is so small compared to container

at high pressure

free volume<container. gas volume becomes a significant portion of container volume

kinetic energy of gases at a given T

all gases have the same avg kinetic energy

gas speeds at the same temp

heavier gas moves slower than a lighter one

effusion

process by which a gas escapes through a small hole in its container

grahams law of effusion

lighter gases move quicker and have a higher rate of effusion

real gases

have volume (size of atoms and bonds between them), experience attractive/repulsive forces, actual pressure of a real gas is lower because molecules are pulled together and strike the walls less

when do real gases deviate the most

high pressures or low temps

van der waals

adjusts the ideal gas law to account interparticle attractions

constant a

factors that have attraction