Conjugate Acids and Bases

Acids - Brønsted Lowry definition

Proton doners

Acids - Arrhenius definition

Generate H₃O⁺ in water

Bases- Brønsted Lowry definition

Proton acceptors

Bases - Arrhenius definition

Generate OH⁻ in water

When you run the reverse reaction

You find the products are also acids and bases

Conjugate acids or bases

Acids and bases that are formed in a reaction

What do conjugate acids/bases determine?

If an acid or base is strong or weak

If the conjugate acid/base readily reacts to run the reverse reaction...

It is a weak acid/base

If it does not react in the reverse reaction

It is a strong acid/base

Strong acids and bases don't have...

A reverse reaction

Strong acids/bases are not what kind of reaction?

An equilibrium reaction

Will stress force a strong acid/base reaction the other way?

No

(There is no way to make it less acidic without a different reaction)

Strong acids to know

-Hydrochloric Acid (HCl)
-Sulfuric Acid (H₂SO₄)
-Nitric Acid (HNO₃)

Strong bases to know

-Sodium hydroxide (NaOH)
-Potassium Hydroxide (KOH)
-Calcium Hydroxide (Ca(OH)₂)
-Strontium Hydroxide (Sr(OH)₂)
-Barium Hydroxide (Ba(OH)₂)

Weak acids and bases and stress

Can be forced the other way

Ammonia is a gas with a distinct odor

-Ammonium and hydroxide are both odorless
-If a base is added to the solution, you will smell ammonia
-If hydroxide is removed, you won't smell anything

Pet "Stain" Problem

-Urine has ammonia in it
-Most cleansers are basic
-After cleaning, we still leaves small amounts behind
-If it is small amount of ammonia and a basic cleanser the equilibrium will be shifted to the ammonia side so some thing with a great sense of smell (dog) could pick it up
-A slightly acidic cleanser shifts the equilibrium to the ammonium side to solve this problem

Weak Acid Examples

-Acetic Acid (Vinegar)
-Citric Acid
-Ascorbic Acid (Vitamin C)
-Boric Acid
-Carbonic Acid

Weak Base Examples

-Sodium Bicarbonate
-Ammonia
-Sodium Hypochlorite (bleach)