CHM 1046L final

Beer’s Law

A=abc

A (absorbance)

a (molar absorptivity)

b (length of light path)

c (concentration)

how do you find the percentage of a sample?

(actual/theoretical) \* 100%

how do you calculate molarity with specific gravity and weight?

(%purity x specific gravity x 10)/molar mass

how do you calculate freezing point?

deltaTf=Kf x b x i

how do you calculate the limiting reactant?

calculate the number of moles of each reactant by multiplying the volume of each solution by its molarity

determine which reactant is limiting by dividing the number of moles of each reactant by its stoichiometric coefficient in the balanced equation

what is the limiting reactant?

the reactant that will be completely consumed in a chemical reaction

what is the percent yield?

the ratio of actual yield to theoretical yield

(actual/theoretical)

how does recrystallization lead to a purification of solid materials?

by heating and cooling

what does saponified mean?

turning fat/oil into soap

turn an ester into an alcohol and a metal salt

what does an ester look like?

acetylsalicylic acid (aspirin) structure

phenyl (benzene) ring structure

physical properties definition

properties of matter that don’t involve chemical changes

ex.) color, hardness, boiling point

chemical properties definition

properties that can be observed in a chemical reaction

ex.) flammability, pH, toxicity

what is the Van’t Hoff factor?

i

number of particles in an aqueous solution

colligative properties definition

properties that are independent of the nature of the solute and only depend on solute concentration

ex.) vapor pressure lowering, freezing point depression, boiling point elevation, osmotic pressure

what is a mixture?

2 or more substances that are not chemically combined and can be easily separated

what is decantation?

the process of separation of a liquid from a solid by gently pouring the liquid from the solid without disturbing the solid

what is filtration?

the process of separating a solid from a liquid by means of a porous substance or a filter

what is extraction?

the separation of a substance from a mixture by preferentially dissolving the substance in a suitable solvent

what is sublimation?

the process where a solid passes directly to the gaseous state and back to the solid state

beaker

what is specific gravity? (relative density)

a measure of the density of a substance in comparison to the density of water

salicylic acid structure

acetic anhydride structure

what is esterification?

a reaction of an alcohol with an acid to produce an ester and water

erlenmeyer flask

what is aspirin?

an analgesic (painkiller) and antipyretic (fever reducer)

why does one test for phenols when making aspirin?

it’s toxic to stay in aspirin

what are amphoteric substances?

substances that can act as an acid or base

ex.) water

Lewis definition

base is the electron pair donor

acid is the electron pair acceptor

Arrehenius definition

acids produce H+ ions in an aqueous solution

what is chemical kinetics?

the study of how fast reactions proceed and factors that affect the rates of reaction

ex.) nature of reactants, concentration of reactants, catalysts

what is a catalyst?

a substance that affects the rate of a reaction without being consumed

enzyme

what is a solvent?

major component

what is a solute?

minor component

what are spectator ions?

ions that exist in the same form on the reactant and product sides of a chemical reaction

do not participate in chemical reactions

what is a Bronsted-Lowry acid?

proton donors

what is a Bronsted-Lowry base?

proton acceptors

what is a net ionic equation?

chemical equation that only shows the ions that are directly involved in the chemical reaction

what is a salt?

the product of an acid-base reaction

ex.) NaCl

anion definition

from acids, conjugate base of a strong acid with a neutral pH

negatively charged ion

cation definition

from strong bases are pH neutral

positively charged ion

volumetric flasks

filter flask

buret

graduated cylinder

concical funnel

crucible and cover

pasteur pipet with rubber bulb

evaporating dish

watch glass

glass rod with rubber policeman

test tube

test tube brush

medicine dropper

volumetric pipet

transfer pipets

buchner funnel

bunsen burner

hot plate

extension clamp

flame spreader

clay triangle

heating block

clamp holder

sand bath

burner striker

wire gauze with ceramic center

double buret clamp

test tube holder

thermometer

support stand with ring stand

crucible tongs

mortar and pestle

oxidize (oxidation)

decrease in the number of atoms

reduce (reduction)

increase in the number of atoms

oxidation-reduction reaction

a reaction that involves the transfer of electrons between chemical species (atoms, ions, molecules)

redox couple

the combination of the oxidized and reduced substances in a half reaction

salt bridge

connects the 2 half cells and permits ionic flow into and out of the cells

cathode

receives electrons

electrode where reduction occurs with positive polarity

anode

supplies electrons

electrode where oxidation occurs with negative polarity

spontaneous process

occurs without energy input

nonspontaneous process

requires an energy input

reversible process

takes place back and forth between 2 ends

non-spontaneous processes

irreversible process

takes place in one direction

spontaneous processes

galvanic cell (voltaic cell)

a battery, a spontaneous electrochemical cell

anode connects to negative probe, oxidation

cathode connects to positive probe, reduction

electrolytic cell

a cell where electrolysis occurs

electromotive force (EMF)

the difference in electrical potential between 2 half cells

Ecell

Gibbs free energy equation

deltaG=deltaH-TdeltaS

relationship between deltaG and Ecell

EcelldeltaG=-n

Henderson-Hasselbach equation

pH=pKa + log \[base/acid\]

what is a hydroxide?

OH-

diatomic anion

one covalent bond

what does an ether look like?

how do you test for the presence of phenol?

by using FeCl3 (iron chloride)

if the solution turns dark purple/violet then phenols are present

what is phenol?

a benzene ring with a hydroxide attached

presence of it tested in aspirin creation

what is FeCl3?

iron chloride, iron 3, ferric chloride

used to test for the presence of phenols in aspirin

what is cyclohexane? (+ structure)

6 carbon atoms linked by a single bond, 18 single bonds

non-polar and saturated

colorless and flammable

what is cyclohexene? (+ structure)

6 single bonded carbon atoms, one double bond

alkene functional group

clear organic liquid

what is an electrolyte?

anything that conducts energy

strong: complete dissociation

weak: incomplete dissociation