Chapter 9 Study Guide

Equilibrium Constant (K)

K = [products]/[reactants], the coefficients to each reactant/product become the exponent

Neutral pH

pH = 7

Acidic pH

pH < 7

Basic pH

pH > 7

Strong Acid: HCl

hydrochloric

Strong Acid: HBr

hydrobromic

Strong Acid: HI

hydroiodic

Strong Acid: HNO₃

nitric

Strong Acid: H₂SO₄

sulfuric

Strong Acid: HClO₄

perchloric

Arrhenius Acid

produces H⁺

Arrhenius Base

produces OH⁻

Bronsted-Lowry Acid

proton donor

Bronsted-Lowry Base

proton acceptor

Strong Acids

fully ionize; large Ka and small pKa

Weak Acids

partially ionize; small Ka and large pKa

Strong Bases

Group 1 & 2 metal hydroxides

(LiOH, KOH, NaOH, and Ca(OH)2

Weak Bases

ammonia (NH₃) & amines

Neutralization Reaction

acid + base → salt + water

Equilibrium Constant Meaning

K > 1: products favored; K < 1: reactants favored

Ka

acid dissociation constant

pKa

-log(Ka)

SMALLER pKa, STRONGER acid

pH Calculation

pH = -log[H⁺]

Relationship Between pH and pKa

If pH < pKa → acid form predominates; If pH > pKa → base form predominates

What does it mean for the solution or acid when the pH is below the pKa value.

It's mostly protonated

What does it mean for the solution or acid when the pH is above the pKa value.

It's mostly deprotonated

What is always produced in a reaction between a strong acid and strong base?

water and salt

Antacids

neutralize the acids in the stomach (HCl), some are mixtures of aluminum hydroxide and magnesium hydroxide

K=1

equal amounts of products and reactants

K>1

products predominate

K<1

reactants predominate

What is the Ka value for all weak acids?

less than 1

What is the Ka value for all strong acids

greater than 1

Conjugate Acid

an acid that forms when a base gains a proton

Conjugate Base

a base that forms when an acid gives up a proton

Relationship between a stronger acid and its conjugate base

The stronger the acid, the weaker its conjugate base

Autoionization of Water

(H₂O + H₂O ⇌ H₃O⁺ + OH⁻)

Water can act as an acid or base

If an acid is added to water, what increases and what decreases?

H₃O⁺ increases, OH⁻ decreases, which makes the solution acidic

(vice versa if you add a base)