Chapter 12: Acids And Bases

Question 1

What is a monobasic acid?

1

Answer 1

-molecules of which dissociate to give one H+ ion in aqueous solution

Question 2

What is a dibasic acid?

1

Answer 2

-a molecule of which can dissociate to give two H+ ions in aqueous solution

Question 3

What is a tribasic acid?

1

Answer 3

-a molecule of which can dissociate to give three H+ ions in aqueous solution

Question 4

Give examples of monobasic acids

2

Answer 4

• nitric acid

- hydrochloric acid

Question 5

Give an example of a dibasic acid

1

Answer 5

-sulfuric acid

Question 6

Give an example of a tribasic acid

1

Answer 6

-phosphoric acid

Question 7

What does it mean if an acid fully dissociates in water?

1

Answer 7

-almost every molecule breaks to give H+ ions

Question 8

What is a H+ ion?

2

Answer 8

• a hydrogen atom that has lost an electron

- a bare proton

Question 9

Why does a bare proton not exist independently in solution?

1

Answer 9

-the H+ ion reacts with water molecules to form the H30+ ion

Question 10

What is a dative covalent bond/coordinate covalent bond?

1

Answer 10

-when both electrons in a bond come from the same atom

Question 11

Describe the bonding of a hydronium ion.

2

Answer 11

• one of the lone pairs on the oxygen atom forms a covalent bond with the proton
• forming a dative/coordinate covalent bond

Question 12

What is the OH- ion commonly called?

1

Answer 12

-hydroxide ion

Question 13

List the shortcomings of the Arrhenius Theory

3

Answer 13

• bare H+ ions don’t exist
• restricted to aqueous solutions
• not all acid-base reactions require water

Question 14

Describe how bare H+ ions not existing is a shortcoming of Arrhenius’ Theory.
(1)

Answer 14

-it is hydronium ions, rather than the bare H+ ions that exist in solution

Question 15

Describe why restricting to aqueous solutions was a shortcoming of Arrhenius’ Theory.
(1)

Answer 15

-solvents such as liquid ammonia, benzene and methylbenzene are excluded from his definitions

Question 16

Describe why not all acid-base reactions require water

2

Answer 16

• when ammonia gas and hydrogen chloride gas come in contact with each other, white fumes of ammonium chloride are formed
• however, the Arrhenius definitions would not allow us to classify this reaction as an acid-base reaction since there is no water present

Question 17

What is an amphoteric/amphiprotic substance?

2

Answer 17

• a substance that can act either as an acid or base

- a substance that can donate or accept protons

Question 18

Give an example of an amphoteric/amphiprotic substance.

1

Answer 18

-water