Chapter_16_Lecture_acid_base_equillibria1

What is the Arrhenius definition of an acid?

An acid is a substance that increases the concentration of hydrogen ions when dissolved in water.

What is the Arrhenius definition of a base?

A base is a substance that increases the concentration of hydroxide ions when dissolved in water.

According to the Brønsted–Lowry theory, what is an acid?

A proton donor.

According to the Brønsted–Lowry theory, what is a base?

A proton acceptor.

What do Brønsted–Lowry acids and bases require for their definitions?

A Brønsted–Lowry acid must have a removable (acidic) proton and a base must have a pair of nonbonding electrons.

What term is used to describe substances that can act as either acids or bases?

Amphiprotic.

When an acid dissolves in water, what does water act as?

Water acts as a Brønsted–Lowry base and abstracts a proton (H+) from the acid.

What are conjugate acid-base pairs?

An acid and a base which differ from each other only in the presence or absence of a proton.

What happens to the conjugate base when an acid donates a proton?

The conjugate base of a substance is the parent substance minus one proton.

What is the characteristic of strong acids in water?

Strong acids are completely dissociated in water and their conjugate bases are quite weak.

What happens to weak acids in water?

Weak acids only dissociate partially in water and their conjugate bases are weak bases.

How is the ion product constant for water expressed?

Kw = [H3O+][OH-], where at 25°C, Kw = 1.0 × 10^-14.

What is the pH of pure water?

The pH of pure water is 7.00.

What does a lower pH than 7 indicate?

An acid with a higher [H3O+] than pure water.

What does a higher pH than 7 indicate?

A base with a lower [H3O+] than pure water.

If the Ka value is greater, what does that indicate about the acid?

The greater the value of Ka, the stronger the acid.

How is percent ionization calculated?

Percent ionization = ([H+] equilibrium/[HA] initial) × 100.

How does the equilibrium favor in an acid-base reaction?

The equilibrium will favor the reaction that moves the proton to the stronger base.

What defines a Lewis acid?

Lewis acids are defined as electron-pair acceptors.

What defines a Lewis base?

Lewis bases are defined as electron-pair donors.