CHEM1B - Ch 6, Ch 7, Ch 8

HCl, HBr, HI, HClO₄, H₂SO₄

strong acids

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

strong bases

have a K_a value of less than 1 but greater than K_w

weak acids

have a K_b value of less than 1 but greater than K_w

weak bases

are conjugate bases of weak acids strong or weak bases?

• they are stronger than the conjugate bases of strong acids

• but they are still weak bases overall

• their K_b is less than 1 but greater than K_w

are conjugate acids of weak bases strong or weak acids?

• they are stronger than the conjugate acids of strong bases

• but they are still weak acids overall

• their K_a is less than 1 but greater than K_w

which ions have no acidic or basic properties in water?

• alkali metal ions: Li⁺, Na⁺, Rb⁺, Cs⁺

• some alkaline earth metal ions: Ca²⁺, Sr²⁺, Ba²⁺

do conjugate bases of strong acids affect pH in water?

• conjugate bases of strong acids: Cl^-, Br^-, NO₃^-, ClO₄^-, HSO₄^-

• these ions have no basic properties in water (K_b « K_w)

• exception: HSO₄^- has weak acidic properties (can donate H⁺)

state in which the forward reaction is equal to the reverse reaction

equilibrium

A substance that produces H⁺ ions in water.

Arrhenius acid

A substance that produces OH⁻ ions in water

Arrhenius base

A substance that donates a proton (H⁺)

Brønsted–Lowry acid

A substance that accepts a proton (H⁺)

Brønsted–Lowry base

KCl, KNO₃, NaCl, NaNO₃,

all make neutral solutions

anion acts as a base; cation has no effect on pH

basic solution

cation acts as an acid; anion has no effect on pH

acidic solution

cation is from strong base; anion is from strong acid

KCl, KNO3, NaCl, NaNO3

cation is from strong base; anion is from weak acid

NaC2H3O2, KCN, NaF

cation is conjugate acid of weak base; anion is from strong acid

NH4Cl, NH4NO3

cation is conjugate acid of weak base; anion is conjugate base of weak acid

NH4C2H3O2, NH4CN

a solution that resists changes in pH when small amounts of acid or base are added (usually containing and weak acid or base plus their conjugates)

buffer solution

system is at equilbrium

Q = K

reaction goes left from products to reactants

• forward reaction is slower than reverse reaction ( reactants are being made faster than products)

Q>K

reaction goes right from products to reactants

• forward reaction is faster than reverse reaction (products are being made faster than reactants)

Q<K

when is Kp > Kc?

when more moles of gas are on the product side

when is Kc > Kp?

when more of gas are on the reactant side

if the reaction is product-favored, where is heat?

heat is a product, reaction is endothermic

if a reaction is reactant-favored, where is heat?

heat is a reactant, reaction is exothermic

if heat is a reactant, what happens when temperature increases?

equilibrium shifts right

if heat is a product, what happens when temperature increases?

equilibrium shifts left

Temperature increases and K decreases — what does this say about heat?

• Reaction is exothermic

• Heat is a product

• System shifts toward reactants to consume added heat

Temperature increases and K increases — what does this say about heat?

• Reaction is endothermic

• Heat is a reactant

• System shifts toward products to absorb added heat