Gen Chem II ACS Exam

0 order rate law

[R]t=[R]0-Kt

1st order rate law

[R]t=[R]0e^-Kt

2nd order rate law

(1/[R]t)=(1/[R]0)+Kt

mass percent

mass solute/moles solution

Molarity

Moles solute per liter of solution

Molality

moles of solute per kilogram of solvent

Change in boiling/freezing point

ΔT=K*i*m

Enthalpy of a reaction

ΔHºrxn=ΔHºproduct-ΔHºreactant

Entropy

ΔS=change in temp/original temp

Gibbs free energy spontaneity

negative=spontaneous, positive=nonspontaneous

Gibbs free energy (with ΔH)

ΔG = ΔH - TΔS

K

K=products/reactants (at equilibrium)

ΔG (with K)

G = -RT ln K

Acid

A substance that donates protons (H+) in a chemical reaction and creates H₃O⁺ with water

Base

A substance that accepts protons (H+) in a chemical reaction and typically produces OH^- ions in water.

K_a

K_a=[A^- ][H₃O⁺]/[HA]

K_b

K_b=[BH⁺][OH^-]/[B]

pH

pH=-log[H₃O⁺]

K_w

K_w=K_aK_b=1.0×10^-14=[H₃O⁺ ][OH-]

pKa

pKa=-logK_a

Henderson Hasslebach

pH=pKa+log[A^-]/[HA]

Buffer

A solution that resists changes in pH when small amounts of acid or base are added. It is typically composed of a weak acid and its conjugate base.

Titration equivalence point

The point in a titration where the moles of HA started with is equal to moles of base added, resulting in complete neutralization of the acid-base reaction. (Everything is conjugate base)

Half equivalence point

The point in a titration where half of the acid has been neutralized by the base, resulting in equal concentrations of the weak acid and its conjugate base, thus allowing for the determination of pKa.

Gibbs free energy and standard reaction potential

ΔGº=-nFEº

Standard reaction potential and equilibrium constants

Eº=RT/nF(lnK)

Eº_cell

Eº_cell=Eº_ox+Eº_red

E

E=Eº-RT/nF(lnK)

Alpha particle

⁴₂a

Beta particle

⁰_-1β

Positron

⁰
₊₁β

Gamma ray/photon

⁰₀γ

Max N/P

1.537

fission

The process of splitting a heavy atomic nucleus into two or more lighter nuclei, along with the release of energy and neutrons.

Fusion

The process in which two light atomic nuclei combine to form a heavier nucleus, releasing energy.