CHM-6 Acids and Bases

Question 1

What is an acid?

Answer 1

A proton (hydrogen ion) donor.

Question 2

What is the acid dissociation constant?

Answer 2

Quantifies the extent of dissociation of a weak acid.

• High constant = Stronger Acid
• Low constant = Weaker acid

Question 3

Equation to calculate Acid Dissociation Constant.

Answer 3

Ka = [Product 1 + Product 2]/Acid

Question 4

Describe how an acid dissolves in water.

Answer 4

A proton (hydrogen ion) is transferred to water to produce a hydronium ion and a negative ion, depending on the acid.

Question 5

An acid which is 100% ionised in solution is a…

Answer 5

Strong acid

Question 6

What would the reaction of HCl and water look like?

Answer 6

HCl + H20 ---> H3O+ + Cl-
or
HCl ---> H+ Cl-
or
Hydrogen Chloride + Water ---> Hydronium + Chloride ions

Question 7

Equation to calculate pH.

Answer 7

pH = -log10 [H+]

Question 8

What is a weak acid?

Answer 8

An acid that doesn’t ionise fully when dissolved in water

Question 9

What is pKa?

Answer 9

A way of interpreting the Ka equilibrium without scientific notation

Question 10

How to calculate pKa?

Answer 10

pKa = -log10 Ka

Question 11

What are the two varieties of acid?

Answer 11

Binary Acids - Composed of hydrogen and a nonmetal

Oxyacids - Composed with covalent bonds in this fashion: H-O-X. Where X is a given element.

Question 12

Oxyacids with……are more acidic.

Answer 12

More oxygen atoms bonded to the central atom

Question 13

How would a diprotic (two protons) reaction look?

Answer 13

Ka1 = Etc….
+
Ka2=Etc….
Two different equilibrium constants for each proton produced.

Question 14

How would you calculate the equilibrium constant for a base?

Answer 14

Kb = [Product 1+ + Product 2-]/Base (OH-)

Question 15

Which bases are strongest?

Answer 15

Hydroxides of group 1A Metals

Question 16

What is a conjugate Acid-Base Pair?

Answer 16

2 species that are related by 1 H+ (Proton)

E.g H2O and H3O+ have a difference of H+

Question 17

A Strong acid has a……conjugated base

Answer 17

Weak (And vice versa)

Question 18

What is the ion product constant for water?

Answer 18

Kw = [H+]+[OH-] = 1.0 x 10/-14

Question 19

How is the H+ value from the acid dissociation found?

Answer 19

Using the “ICE Method”

Question 20

What does ICE stand for?

Answer 20

INITIAL Acid [H+] concentration
CHANGE in acid [H+] concentration
Acid [H+] concentration at EQUILIBRIUM
(Concentration is known as ‘x’)

Question 21

What is a salt? (4 Points)

Answer 21

Ionic compound
The anion isn’t OH- or O2-
The cation isn’t H+
Composed of cation and anion

Question 22

Which reaction do an acid and base form salt and water?

Answer 22

Neutralisation Reaction

Question 23

What is salt hydrolysis?

Answer 23

When a salt reacts with water to give an acid or base.

Question 24

The weaker the conjugate acid…

Answer 24

the stronger the conjugate base

Question 25

What is a buffer?

Answer 25

A solution that resists pH changewhen a small amount of acid or base is added or when a solution is diluted.

Question 26

What does a buffer consist of?

Answer 26

A mixture of a weak acid and its salt
or
A mixture of a weak base and its salt.

Question 27

The range in which a buffer maintains it’s pH is known as the…

Answer 27

Buffering Capacity

Question 28

The Henderson-Hasselback equation

Answer 28

pH = pKa -log ([Salt]/[Acid])

Question 29

What is an amphoteric substance?

Answer 29

One that can act as either an acid or a base, such as water

Question 30

What happens after the equivalent point when a Weak acid reacts with a strong base?

Answer 30

The curve follows the pattern of a strong acid, rather than a weak one.