4.8 Introduction to Acid-Base Reactions

A specific type of chemical reaction in which a proton, H+, is transferred from one species to another species

Acid-base reaction

The species that gives off a proton in an acid-base reaction:

Acid

The species that accepts a proton in an acid-base reaction:

Base

What is important to identify regarding acid-base reactions?

Both identify if a reaction is an acid-base reaction and also identify the acids and bases within an acid-base reaction

By the Brønsted-Lowry definition, an acid is a substance that:

Donates a proton (H+) in a reaction

By the Brønsted-Lowry definition, a base is a substance that:

Accepts a proton (H+) in a reaction

When an acid transfers a proton to a base, the acid becomes the:

Conjugate base

The acid and the conjugate base make a:

Conjugate acid-base pair

When a base accepts a proton from an acid, the base becomes a:

Conjugate acid

The base and the conjugate make a:

Conjugate acid-base pair

A conjugate acid-base pair will always differ by:

1 proton

Is water a unique species in acid-base reactions?

Yes

Why is water a unique species in acid-base reactions?

It can act as either an acid or a base

How does water act as an acid?

By donating a proton

After water donates a proton, it becomes:

hydroxide, OH-

How does water act as a base?

By accepting a proton

What does water become after accepting a proton?

Hydronium, H3O+

General formulas for reactions of acids with water:

HA + H2O → H3O+ + A-

Identify the acid, base, conjugate acid, and conjugate base from this formula:

HA + H2O → H3O+ + A-

Acid: HA, Base: H2O, Conjugate acid: H3O+, Conjugate base: A-

Identify the conjugate acid-base pairs from this formula:
HA + H2O → H3O+ + A-

HA and A-, H2O and H3O+

General formula for reactions of bases with water:

B + H2O → OH- + HB+

Identify the base, acid, conjugate base, and conjugate acid from this formula:

B + H2O → OH- + HB+

Base: B, Acid: H2O, Conjugate base: OH-, Conjugate acid: HB+

Identify the two conjugate acid-base pairs from this function:

B + H2O → OH- + HB+

B and HB+, H2O and OH-

Can acids and bases differ in strength?

Yes

A strong acid or base will:

Ionize completely in water

% ionization of weak acid or base:

Less than 100%

Reactions between strong acids and bases with water use single or double arrows?

Single

Why do reactions between strong acids and bases with water use single arrows?

To indicate that at the end of the reaction no strong acid or base remains and 100% of it has become the products

Reactions between weak acids and bases with water use single or double arrows?

Double

Why do reactions between weak acids and bases with water use double arrows?

To indicate that at the end of the reaction some weak acid or base will remain

Why will some weak acid or base remain at the end of the reaction with water?

Because less than 100% of it has become the products

A stronger acid will form a ______ conjugate base

Weaker

A weaker acid will form a _____ conjugate base

Stronger

A stronger base will form a ______ conjugate acid

Weaker

A weaker base will from a ______ conjugate acid.

Stronger

An acid-base reaction will favor the formation of the stronger/weaker acid and base

Weaker

Does the conjugate of a strong acid or strong base have acidic or basic properties?

No

6 strong acids:

Hydrobromic acid HBr

Hydrochloric acid HCl

Hydroiodic acid HI

Nitric acid HNO3

Perchloric acid HClO4

Sulfuric acid H2SO4

The strong bases are:

Lithium Hydroxide LiOH

Sodium Hydroxide NaOH

Potassium Hydroxide KOH

Rubidium Hydroxide RbOH

Calcium Hydroxide Ca(OH)2

Strontium Hydroxide Sr(OH)2

Barium Hydroxide Ba(OH)2