Chapter 10 - Acids and Bases

What is the definition of pH?

Power of hydrogen ion concentration

What is pH used for?

Used to measure hydrogen ion concentration in water

What is the formula for pH and pOH?

pH= -log[H+] and pOH= -log [OH-]

Stronger acids have (higher/lower) Ka, and (higher/lower) pKa values.

Stronger acids have higher Ka, and lower pKa values

Weak bases have (higher/lower) Kb values, and (higher/lower) pKb values.

Weak bases have lower Kb values, and higher pKb values

A strong acid dissociates (completely/partially) in water to produce a (large/small) amount of (hydrogen/hydroxide) ions

A strong acid is one that dissociates completely in water to produce a large amount of hydrogen ions

A weak acid dissociates (completely/partially) in water to produce a (large/small) amount of (hydrogen/hydroxide) ions

A weak acid dissociates partially in water to produce a small amount of hydrogen ions

A weak base dissociates (completely/partially) in water to produce a (large/small) amount of (hydrogen/hydroxide) ions

A weak base dissociates partially in water to produce a small amount of hydroxide ions

A strong base dissociates (completely/partially) in water to produce a (large/small) amount of (hydrogen/hydroxide) ions

A strong base dissociates completely in water to produce a large amount of hydroxide ions

What happens to the acidity of binary acids as the atomic radius of the halogen atom increases?

For binary acids, as the atomic radius of the halogen atom increases, the acidity increases

What are the four strong oxoacids?

HNO3, H2SO4, HClO4, and HClO3

What are the three strong binary acids?

HCl, HI, and HBr

As the value of pKb increases, what happens to the strength of the base?

As the value of pKb increases, the strength of the base decreases

As the value of pKa decreases, what happens to the strength of the acid?

As the value of pKa decreases, the strength of the acid increases

What are three common Group 1 strong bases?

LiOH, NaOH, and KOH

What is the definition of a Bronsted-Lowry acid?

A molecule that acts as a proton donor during an acid-base reaction

What do Bronsted-Lowry bases possess?

Must possess a lone pair of electrons in order to receive a proton

What is the relationship between an acid and its conjugate base?

Stronger the acid, weaker its conjugate base.

Weaker the acid, the stronger its conjugate base

What is an Arrhenius base?

Any species that dissolves in aqueous solution to produce hydroxide ions

Are all Arrhenius bases Bronsted-Lowry bases?

Yes

Are all Bronsted-Lowry bases also Arrhenius bases?

No. NH3 (ammonia) is an example of this. It can accept a hydrogen ion, fulfilling the definition of a Bronsted-Lowry base. However, NH3 cannot form OH- in water, as such it is not an Arrhenius base

What term describes a molecule that acts as an electron pair acceptor?

Lewis acid

What term describes a molecule that acts as an electron pair donor?

Lewis base

What do Lewis bases possess?

A lone pair of electrons

What reactants and products are involved in a neutralization reaction?

Reactants: strong acid and strong base

Products: salt and water

What happens to the protons and hydroxyl ions in a neutralization reaction?

All protons (H+) and hydroxide ions (OH-) present in solution combine to form water and the reaction goes to completion

What strengths of an acid and base is required to form a basic salt in a neutralization reaction?

A strong base would react with a weak acid to produce a basic salt

What strength of acid and base is required to form an acidic salt in a neutralization reaction?

A strong acid would react with a weak base to produce an acidic salt

What type of salt forms in a neutralization reaction between a strong acid and a strong base?

A neutral salt

What is the definition of a buffer?

A solution that resists a change in pH when either an acid or base is added

What is a buffer comprised of?

An acidic component and a basic component. The acid component reacts to the addition of a base. The base component reacts to the addition of an acid

How do you form a buffer solution?

Mixing a weak acid with its conjugate base or mixing a weak base with its conjugate acid

Write the equation depicting the addition of strong acid (H3O+) to a buffer solution of acetic acid (CH3COOH) and NaCH3COO- (sodium acetate)

CH3COO- + H3O+ ⇋ CH3COOH + H2O

Write the equation depicting the addition of strong base (OH-) to a buffer solution of acetic acid (CH3COOH) and NaCH3COO- (sodium acetate)

CH3COOH + OH- ⇋ CH3COO- + H2O

Which common formula is used to calculate the pH in buffers?

Henderson-Hasselbach equation

If you titrate a weak base with a strong acid, would the equivalence point pH be somewhat acidic or basic?

Somewhat acidic

If you titrate a weak acid with a strong base, would the equivalence point pH be somewhat acidic or basic?

Somewhat basic

Is NO3- a Bronsted-Lowry base?

It is a Bronsted-Lowry base as it has a lone pair of electrons to accept a proton

Is NO3- an Arrhenius base?

It is not an Arrhenius base as it does not form OH- in water

What is the molecular formula for perchloric acid and chloric acid?

HClO4 and HClO3, respectively

What is the molecular formula for sulfuric acid and sulfurous acid?

H2SO4 and H2SO3, respectively

What are the three Group 2 strong bases?

Ca(OH)2, Sr(OH)2, and Ba(OH)2

Why is AlCl3 considered acidic?

Al3+ behaves as an acid because it accepts hydroxide ions from solution.

Why is the Henderson-Hasselbach equation limited to weak acids?

Because strong acids dissociate completely, leaving [HA] = 0. Plug in '0' as your denominator and the equation will not work

The pKa of a compound is 2.0. If this compound was dissolved in water, would the resulting solution be acidic or basic?

pKa + pKb = 14.If pKa =2, then pKa < pKb, meaning that Ka > Kb. Resulting solution will be more acidic

Why is NaCl considered a neutral salt?

In NaCl, both the cation and the anion are conjugates of a strong acid and strong base

Why is NaF not considered a neutral salt?

In NaF, F- is the conjugate base of HF, which is a weak acid

Is pH and pOH temperature dependent?

Yes, increasing the temperature decreases both pH and pOH, so that the pH + pOH = 14 equation no longer holds up. However, this does not necessarily mean that the solution is now more acidic/basic in any way

Is this reaction considered a neutralization reaction?

HCl + H2O ⇌ H3O+ + Cl-

No. In a neutralization reaction, the products should be a neutral salt and water.

What is the only strong polyprotic acid?

H2SO4

What is the definition of an amphoteric salt?

A salt with both acid and basic characteristics. An example is Al(OH)3