Quicksheet: General Chemistry

Solubility rule 1

All salts containing alkali metals (Group 1) or ammonium (NH4+) cations are water soluble

Solubility rule 2

All salts containing the nitrate (NO3-) or acetate (CH3COO-) anions are water soluble

percent composition by mass

mass solute/mass solution * 100%

mole fraction

#mol compound/total # mol

molarity

#mol solute/L of solution

molality

#mol solute/kg of solvent

normality

#gram equivalent weights of solute/L solution

Ksp vs IP

• solubility product constant - equilibrium constant for a dissociation rxn

• ionization potential -determines level of saturation and behavior of the solution

IP<Ksp

IP=Ksp

IP>Ksp

• solution is unsaturated, more will dissolve

• solution saturated (equil)

• solution supersaturated, precipitate will frm

dilution formula

M₁V₁ = M₂V₂

titration formula

N_aV_a = N_bV_b

• N = normality (mol/L)

experimental rate law equation

rate = k[A]^x[B]^y

equilibrium constant

Kc = [products]/[reactants]

Keq

equillibrium constant

• characteristic of a given system at a given temperature

Keq»1

equil mixture contains very little reactants compared to products

Kequ«1

equil mixture contains very little products compared to reactants

Keq close to 1

equil mixture of products and reactants are equal

La chatelier’s principle

system to which stresses (change in [], pressure, vol, temp) are applied tends to change to relieve applied stress

1 atm =

760 mmHg = 760 torr = 101,325 Pa

Boyle’s Law

P₁V₁ = P₂V₂

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Charle’s Law

V₁/ T₁ = V₂/ T₂

• Charles V likes tea

Gay-Lussac’s Law

P₁/ T₁ = P₂/ T₂

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Avogadro’s principle

V₁ / n₁ = V₂ / n₂

combined gas law

P₁V₁/ T₁ = P₂V₂/ T₂

Dalton’s law

of partial pressure - total pressure of a gaseous mixture is equal to the sum of the partial pressures of the individual components

decrease volume of sample of gas

• behave less ideally b/c individual gas particles are closer proximity

• more likely to engage in intermolecular interactions

• inc. pressure/dec. temp

as pressure of gas increases

• gas’s volume is less that would be predicted by ideal gas law due to intermolecular attraction

• dec. volume

as temp of gas decreases

• dec. average vel.

• attractive intermolecular forces become increasingly significant

• gas have smaller vol than predicted

isotope

same # protons (same atomic number) but different # neutrons (different mass numbers)

Planck’s quantum theory

energy emitted as electromagnetic radiation from matter exists in discrete bundles called quanta

formal charge

charge of an atom would have if all the electrons in bonds were charged equally

• V - L - 1/2B

oxidizing agent

causes another atom to undergo oxidation, and is itself reduced

reducing agent

causes another atom to be reduced and is itself oxidized

Galvanic cell

redox rxn occurs with a negative △G; supply energy and are used to do work

how is energy harnessed from Galvanic cells

placing the ox-red half reactions in half cells which are connected by an apparatus that allows for the flow of electrons

electrolytic cells

redox rxn has positive △G; electrical en required to induce a rxn; half rxns placed in one container

reduction potential

tendency of a species to acquire electrons and be reduced

• lose H+; gain electrons

standard reduction potential

used to calculate standard electromotive force (Ecell) of rxn = E_cathod - E_anode

• measured under standard conditions: 25 C, 1M, 1 atm

Gibbs free energy of

thermodynamic criterion for determining the spontaneity of rxn - △G = -nFE_cell

Arrhenius A/B

-a: species that produces excess H+ in aqueous solution

-b: species that produces excess OH-

Bronsted-Lowry A/B

-a: donates protons

-b: accepts proton

Lewis

-a: electron pair acceptor

-b: electron pair donor

strong acids

HCl, HI, HBr, H₂SO₄, HClO₃, HClO₄, HNO₃

strong bases

LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)₂, Sr(OH)₂, Ba(OH)₂

amphoteric species

one that can act either as an acid or a base, depending on its chemical environment

titration

used to determine molarity of A/B by reacting a known volume of solution of unknown [] with known volume of solution of known []

• half-equivalence point: pH = pka

henderson-hasselbalch equation

used to estimate pH of solution in buffer region where [] of species and its conjugate are present in approximately equal []s

• pH = pka+log ([A]/[HA])

colligative properties

physical properties derived solely from number of particles present, not the nature of those particles; usually associated with dilute solutions

freezing point depression

△T_f = iK_fm

• m = molality; i = Hoff factor

boiling point elevation

△T_b = iK_bm

• m = molality; i = Hoff factor

osmotic pressure

pi = MRT

• aka van’t Hoff equation

graham’s law

of diffusion

• occurs when gas molecules distribute through a volume by random motion

• rate1/rate2 = (MM2/MM1)^1/2

  • MM or density

Graham’s law of effusion

flow of gas particles under pressure from one compartment to another through small opening

• rate A/rateB = (MMB/MMA)^1/2

graham’s law of diffusion and effusion

r₁/r₂ = (m₂/m₁)^1/2

law of conservation of energy

dictates that energy can be neither created nor destroyed, but that all thermal, chemical, potential, and kinetic energies are interconvertible

isolated system

no exchange of energy/matter with the environment; bomb calorimetry creates this

closed system

can exchange energy but not matter with the environment

open system

can exchange both energy and matter with the environment

example of an open system

human beings can take in energy and matter (eat), and release matter into environment (breath, pee, poop), and release energy into environment (heat transfer from skin and mucous membranes)

isothermal

temp of system remains constant

aidiabatic

not heat exchange occurs

isobaric

pressure of system remains constant

isovolumetric (isochoric)

volume remains constant

heat

transfer of thermal energy from one object to another

endothermic

rxn that absorb thermal energy

exothermic

rxn that release thermal energy

endergonic

rxn that are nonspontaneous

exergonic

rxn that are spontaneous

going up column of PT

increase

• effective charge

• ionization energy

• electronegativity

• electron affinity

decrease

• radius

going left to right on periodic table

-towards noble gases

increase

• effective charge

• ionization energy

• electronegativity

• electron affinity

decrease: atomic radius

polyacrylamide gel electrophoresis (PAGE)

protein migrate through porous matrix according to size and charge

Native PAGE

used to analyze the protein in folded state

SDS-PAGE

uses detergent to break all noncovalent interactions and analyzes the unfolded state

reducing reagents

can be used to break covalent disulfide bonds (S-S to S-H)

structural protiens

generally fibrous; indlcude collagen, elastin, keratin, actin, and tubulin

motor proteins

capable of force generation through a conformational change

• myosin, kinesin, dynein

cell adhesions molecules (CAM)

bind cells to other cells or surfaces

• cadherins, integrins, selectins

ion channels

used to regulating ion flow into or out of a cell:

• ungated channels

• voltage-gated channels

• ligand-gated channels

enzyme linked receptors

participate in cell signaling through extracellular ligand binding and initiation of second messenger cascades

G protein-coupled receptors

have a membrane bound protein associated with a trimeric (molecular switch); also initiate second messenger system

watson-crick model

• DNA backbone composed of alternating sugar and phosphate groups; always read in 5’ to 3’

• two strands with antiparallel polarity, wound into a double helix

DNA polymerase

synthesizes new DNA strands reading the template DNA 3’-5’ and synthesizing the new strand 5’-3’

• leading strand: one primer

• lagging strand: many primers w/ okazaki fragments

DNA cloning

introduces a fragment of DNA into a vector plasmid

restriction enzyme (restriction endonuclease)

cuts both the plasmid and the fragment, leaving them with sticky ends, which can bind; often palindromic

endocytosis and exocytosis

methods of engulfing material into cells or releasing material into the exterior of cells, both vial the cell membrane

pinocytosis

ingestion of liquid into the cell from vesicles formed from the cell membrane (“pint of beer”)

phagocytosis

ingestion of solid material

glycogenesis

glycogen synthesis using two main enzymes: glycogen synthase and branching enzyme

glycogen synthase

which creates alpha 1-4 glycosidic links btwn glucose molecules; activated by insulin in the liver and muscles

branching enzyme

which moves a block of oligoglucose from one chain and connects it as a branch using an alpha 1,6 glycosidic link

glycogenolysis

breakdown of glycogen using two main enzymes:

• glycogen phosphorylase

• debranching enzyme

glycogen phosphorylase

removes single glucose 1-phosphate by breaking breaking alpha 1,4- glycosidic link

• the liver it is activated by glucagon to prevent low blood sugar

• exercising skeletal muscle, it is activated by epinephrine and AMP to provide glucose for the muscle itself

debranching enzyme

moves a block of oligoglucose from one branch and connects it to the chain using an alpha 1,4- glycosidic link

glucogensis

occurs in both the cytoplasm and mitochondria predominantly in the liver; mostly just reverse glycolysis, using the same enzyme

three irreversible steps of glycolysis must be bypassed by different enzymes

• pyruvate carboxylase and PEP carboxykinase bypass pyruvate kinase

• fructose-1,6-biphosphate bypasses PFK

• glucsoe-6-phosphatase bypasses hexokinase/glucokinase

the pentose phosphate pathway

• occurs in cytoplasm of most cells

• generate NADPH and sugars for biosynthesis

• rate limiting enzyme = glucose-6-phosphate dehydrogenase; activated by NADP+ and insulin; inhibited by NADPH

lipid transport

packaging water-insoluble fats into water-soluble lipoproteins for transport in blood/lymph

• chylomicrons, VLDL, IDL, LDL, and HDL

cholesterol metabolism

• obtained through dietary sources or through synthesis in the liver

• key enzyme: HMG-CoA reductase = rate limiting enzyme (controls body production)

Palmitic acid

only fatty acid that humans can synthesize, it produced in the cytoplasm from acetyl-CoA transported out of the mitochondria

fatty acid oxidation

occurs in mitochondria, following transport by the carnitine shuttle via beta-oxidation