IB Chemistry HL review

Relative atomic mass

weighted mass relative to one twelfth of the mass of a carbon-12

Relative Molecular Mass

mass of a molecule calculated through the summation of all the relative atomic masses of its constituent atoms.

Mass number

number of protons and neutrons added together

atomic number

equal to the number of protons in the nucleus of the atom

Isotopes of an element

Isotopes of atoms of the same element contain the same number of protons but differ in neutrons

first ionization energy

minimum energy required to remove a mole of electrons from a mole of gaseous atoms to form a mole of cations in the gaseous state.

X -> X+ and e-

Electronegativity

is the ability of an atom to attract a pair of electrons.

Ligand

neutral molecule or negative ion that donates a pair of electrons to form a coordination complex.

(lewis bases)

Exothermic reaction

releases heat from the formation of energetically more stable products than the reactants. (negative ∆H)

Endothermic reaction

absorbs heat from the surroundings as a result of forming products energetically less stable than the reactants.

Standard Enthalpy of a reaction (∆H)

Heat transferred during a reaction using molar quantites carried out under STP. (1 atm, 298K, and all substances pure in their standard states)

Average bond enthalpy

is the energy required to break a mole of covalent bonds in the reactant, all reactants and products being in the gaseous state.

X--Y -> X(g) + Y(g)

Standard state

the standard state of an element is its most stable state under stp.

Standard enthalpy of formation (∆Hf)

Enthalpy change when one mole of a compound/molecule is formed from its constituent parts.

Standard enthalpy of combustion (∆Hc)

Enthalpy change when one mole of a compound is combusted under STP.

Electron affinity

enthalpy change occuring when a gaseous atom gains one electron to form a negative ion.

*First electron affinity might be endothermic

X(g) + e- > X- (g)

Rate of reaction

is the increase in concentration of one of the products per unit time.

Activation energy

minimum amount of energy required for a chemical reaction to take place

Bronsted Lowry acid-base

Proton donator - Acid

Proton acceptor - Base

Lewis acid-base

substance that can accept a pair of electrons

Substance that can donate a pair of electrons

Oxidation

loss of electrons

Reduction

gain of electrons

Oxidizing/Reducing agent

substance that easily reduces - aiding in oxidation

substance that easily oxidizes - aiding in reduction

Standard Electrode potential

electrode potential relative to a standard hydrogen half-cell, measured under STP ( 1atm, 298K, all solutions at 1M)

Iodine number

is the mass of iodine in grams required to react with 100g of a substance.

Continuous spectrum

shows an unbroken sequence of frequencies or wavelengths, such as the spectrum of visible light.

line spectrum

is a spectrum that only contains certain discrete frequencies of light.

Precision

all taken measurements are close to eachother

A graph with pressure (y) and 1/volume looks like?

straight line because they are inversely proportional

1.0 mol of any gas occupies?

22.4 dm3 at standard conditions

An ideal gas is a gas that does not have?

molecular volume, or inter-particle forces

1 atm equals how many pascals?

1.01325 x 10^5 pascals

The Mass spectrometer steps?

Vaporization, ionization, acceleration, deflection, detection.

continuous vs line spectrum?

continuous contains all the wavelengths/energy, while a line spectrum contains only specific energies/wavelengths.

Lyman Series is?

the ultraviolet series, all transitions end at 1

Balmer series is?

visible light - all transitions end at n=2

Paschen Series

infrared, all transitions end at n=3

Reactions of Alkali metals with water?

alkali metals with water form hydrogen gas and the corresponding alkali (NaOH)

Iodine, Bromine, and Chlorine are what colors?

purple, orangy/brown, and yellow

A complex ion is?

a transition metal, surrounded by ligands

pure covalent bonds have electronegativity values of?

less than .4

ionic bonds have electronegativity values of

greater than 1.7

2 bond pairs 0 lone pairs

linear - bond angle 180

3 bond pairs and 0 lone pairs

trigonal planar - 120

4 bond pairs and 0 lone pairs

tetrahedral 109.5

3 bond pairs and 1 lone pair

trigonal pyramidal 107

2 bond pairs and 2 lone pairs

bent/ v-shaped 104.5

Graphite

Sp2 hybridization - high conductivity (4th electron is found delocalized in the pi bond) - 2 dimensional - very soft (three sheets are weakly attracted to each other by weak van der waal's forces)

Diamond

Sp3 hybridization - no conductivity - very hard - 3 dimensional

Fullerene

Intermediate conductivity - 2 dimensional - soft

if there are 5 bond pairs it is a type of trigonal bipyramidal

classic example (PCl5) - 90 and 120 degree angle

4 bond pairs 1 lone pair

see-saw 90degree and 120

3 bond pairs 2 lone pair

T-Shaped with 90

2 bond pairs 3 lone pairs

linear - 180

6 bond pairs means it is octahedral

classic example (SF6)

6 and zero

octahedral 90

5 bond pairs and 1 lone pair

square pyramidal 90 90

4 bond pairs and 2 lone pairs

square planar 90

Hydrogen bonding occurs only in

Nitrogen, oxygen, or fluroine

sp3 hybridization

all single bonds, tetrahedral, 109.5

sp2

double bond, planar triangle 120

sp

triple bonds or 2 double bonds - linear - 180

a single bond has how many sigma/pi bonds?

1 and zero

a double bond has how many sigma/pi bonds?

1 sigma, 1 pi bond

a triple bond has how many sigma/pi bonds?

1 sigma 2 pi bonds

Resonance structures are?

just structures with the double bond in all locations

Delocalization occurs when?

there is a presence of unhybridized p-orbitals on all of the atoms in the structures.

1 liter of water weighs?

1kg

Arrhenius equation k, A, equals?

rate constant, and prefactor

slope equals?

-Ea/R

where R = universal gas constant

Which enthalpy formula to use?

If given formation enthalpy, use products - reactants.

If given combustion enthalpy or bond enthalpies, use reactants - products. This is only to find the Enthalpy of the reaction. Do not switch signs for any of them.

Entropy signs are?

positive when entropy increases, negative when entropy decreases. (don't get confused)

Entropy can increase by?

Mising, increase in the number of particles, change of state, creation of a gas.

Hydrogen emission spectrum?

series of lines, electrons transitioning energy levels then falling back down. First transition causes UV light, second visible light, and third infrared light.

Differences between an electrolytic and voltaic cell?

non-spontaneous - spontaneous, anode/cathode opposite, requires energy - creates energy, etcs.

When asked to label a voltaic cell remember to? (ionic bridge)

show the movement of both cations and anions

Why are alcohols worse than alkanes as far as fuel is concerned?

Alcohols are partially oxidized, and have stronger intermolecular forces of attraction to hold them together. Making it less favorable to combust than alkanes.

when determining lattice enthalpy strength?

Look at the oxidation states of each atom in each molecule. E.G. MgO or NaF? Which has the greatest enthalpy value?

dynamic equilibrium exists when?

closed system and there are no changes in properties such as concentration.

Kc is only affected by?

temperature - not pressure or anything else.

Any "define enthalpy change" is a definition question haha

Enthalpy of formation: enthalpy change when one mole of a product is formed from its constituent atoms under standard conditions - all under STP.

Protein hydrolysis? reagents, conditions, bond broken?

Reagent- Acid, Conditions - High temperature, Bond broken - peptide bond.

Differences between glucose, galactose, and fructose?

Isolectric point is?

the pH point at which the protein experiences no net charges. (Amine group produces a more positive charge, and therefore more basic pH while the opposite is true for the carboxyl terminal)

Amylose and Amylopectin differences?

both starches but differences in solubility and chain structure.

Differences between alpha and beta pleated proteins?

These secondary structures differ in their hydrogen bonding. Alpha sheets have hydrogen bonding within the protein chain, while hydrogen bonding occurs between other protein chains in beta pleated sheets.

fats and oils differences? similarities?

solid, liquid

both consist of fatty acids and glycerol

galactose is trans, glucose is cis

...

Straight chain structure of glucose?

Two naturally occuring fatty acids?

stearic acid, oleic acid

Two essential fatty acids?

omega 3, omega 6 fatty acids, and linoleic acid

effects of non-competitive inhibitor on km and Vmax?

Km remains unchanged because the active site isn't blocked, but the Vmax decreases because it is achieved in less time.

effects of competitive inhibitor on Km and Vmax?

Km increases - more substrate needed to reach Vmax. Vmax remains the same but it takes longer to get there due to the competitive inhibitor blocking the active sites and causing the reaction to not occur as quickly.

Beta-lactam ring importance?

it is the 90 degree bond angle structure consisting of 3 carbons and 1 nitrogen responsible for reacting with bacteria and causing their cell walls to burst.

Chirality

refers to asymmetry about one atom in optical isomers

overprescription of antibacterials?

kills good bacteria, develops resistence

How to make molecules more soluble in water? (easier to administer)

Make the molecule ionic. If the dominating functional group is a carboxylic acid - react with a base to make the salt. If the dominating group is an amine, react with HCl to make the

Combinatorial Chemistry

various amino acids are attached to resin beads

these products are mixed and split resulting in all combinations of dipeptides

these combinations of dipeptides are then again mixed and split, resulting in many thousands of combinations of peptides.

Enzyme and inorganic catalyst difference?

enzymes are easily denatured by high temperatures, inorganic compounds are not. Enzymes are specific, inorganic compounds are not. etc.

Vitamin A deficiency?

blindness