Chapter 15: Acid-Base Equilibrium Reactions

Question 1

What is the definition of a strong acid and what are considered strong acids?

Answer 1

An acid that completely ionizes (disassociates) in water.
Hydrochloric acid (HCl), Hydrobromic acid (HBr), Hydroiodic acid (HI), Nitric acid (HNO3), Sulfuric acid (H2SO4), and Perchloric acid (HClO4)

Question 2

What does it mean for an acid to completely disassociate? How is this different from partial disassociation?

Answer 2

The H+ wants nothing to do with the rest of the acid (ie NO3-) because both sides of the acid are 100% associated with water. There will be a single arrow and not an equilibrium arrow because their will be no more reactants. In partial disassociation not much product will be made.

Question 3

What is the definition of a weak acid and what are considered to be weak acids?

Answer 3

An acid that partially ionizes (disassociates) in water
Every acid that is not a strong acid

Question 4

What is a polyproduct acid and what is an example of one?

Answer 4

An acid that can donate more than one proton ie H2SO4. It gives the first hydrogen up easily but does not give the second one up easily

Question 5

What is the Bronsted-Lowry definition of acids and bases?

Answer 5

Acid: H+ ion donor
Base: H+ ion acceptor

Question 6

Why is there more than one definition for acids and bases?

Answer 6

The definitions work together because one definition is unable to encompass all the aspects of acids and bases. B-L definition is only one aspect of A/B
some acids and bases do not have hydrogen ions

Question 7

What is Ka for strong and weak acids?

Answer 7

Ka the equilibrium constant for acids.
Strong Ka&raquo_space; 1
Weak Ka < 1
water is not included in the expression because it is a pure liquid

Question 8

What does HA designate?

Answer 8

A weak acid

Question 9

What is the definition of a strong base and what are considered stron bases?

Answer 9

Completely ionize in water
Group 1 or 2 metals + hydroxide ion (OH-)

Question 10

What is the definition of a weak base?

Answer 10

Partially ionize in water

Question 11

What are conjugate acids and bases?

Answer 11

Acids and bases that differ from each other by one proton.

Question 12

What are conjugate acids and bases?

Answer 12

Acids and bases that differ from each other by one proton.

Question 13

How does the strengths of acids and bases compare?

Answer 13

Strong acids = weak bases
weak acids = weak bases
weak acids = strong bases

Question 14

Why is water neutral?

Answer 14

Because there is an equal number of H3O+ and OH- ions

Question 15

When added to water what do acids always produce? What do bases always produce?

Answer 15

Acids: [H+] or [H3O+]
Bases: [OH-]

Question 16

What are the two ways to find [OH-] when pH or [H30+] is known?

Answer 16

pOH –> [OH-], Kw –> [OH-]

Question 17

What must you do to find the pH of a weak acid?

Answer 17

Cannot use pH = -log[H+]
1) Ka
2) find [H3O+] with RICE
3) Use pH = -log[H+]

Question 18

What must you watch out for when finding pH or pOH?

Answer 18

Logarithmic sig figs

Question 19

What is the degree of ionization?

Answer 19

The method by which you check if your assumption was rational.
[H+] equilibrium/[b4 ionization] x 100%.
If it is <5% your assumption was rational

Question 20

Test prep:

Answer 20

Do you know how to write basic dissociation reactions for acids and bases?

Question 21

What is a salt? Which aspect of a salt is linked with an acid/base?

Answer 21

Metal + non metal or cation + anion. Cation w/ base
anion w/ acid

Question 22

What are the combinations of acids and bases to determine the acidity of a salt?

Answer 22

Strong A + Strong B = Neutral salt (NaCl)
Strong A + Weak B = Acidic (NH4Cl)
Weak A + Strong B = Basic (NaF)
Weak A + Strong B = Neutral (NH4CH3COO if Ka = Kb), acidic (NH4F if Ka>Kb), basic if (NH4HCO3, Ka< Kb)

Question 23

What must you consider when determining the pH of a salt??

Answer 23

Is the salt acidic or basic?
Do I have Ka or Kb?
Is the question asking for pH or pOH?