Chapter 4 - Acids and Redox

Question 1

What is an acid?

Answer 1

When dissolved in water, it will release hydrogen ions as protons into the solution.

Question 2

What is a strong acid?

Answer 2

Releases all of its hydrogen atoms into solution.

It completely dissociates in aqueous solution.

Question 3

What is a weak acid?

Answer 3

Releases a small proportion of its available hydrogen atoms into solution.
It partially dissociates in aqueous solution.

Question 4

What is a base?

Answer 4

A base neutralises an acid to form a salt.

Question 5

What is an alkali?

Answer 5

A base that dissolves in water releasing hydroxide ions into the solution.

Question 6

What is the word equation for the neutralisation of acids with metal oxides/hydroxides?

Answer 6

Metal oxide/hydroxide + acid -> salt + water

Question 7

What is the word equation for the neutralisation of acids with alkalis?

Answer 7

Acid + alkali -> salt + water

Question 8

What is the word equation for the neutralisation of acids with carbonates?

Answer 8

Carbonate + acid -> salt + water + carbon dioxide

Question 9

What is a titration?

Answer 9

A technique used to accurately measure the volume of one solution that reacts exactly with another solution.

Question 10

What are titrations used for?

Answer 10

Finding the concentration of a solution.
Identification of unknown chemicals.
Finding the purity of a substance.

Question 11

What are concordant results?

Answer 11

Within 0.10 cm^3 of each other.

Question 12

When can a mean titre be worked out?

Answer 12

When two or more concordant results are obtained.

Question 13

In an acid base titration, what rule is used to determine a solution’s concentration?

Answer 13

n(1)=n(2)

c(1)V(1)=c(2)V(2)

Question 14

When is the oxidation number zero?

Answer 14

For elements on their own or bonded to atoms of the same element.

Question 15

What is the common oxidation number of oxygen?

Answer 15

-2

Question 16

What is the common oxidation number of hydrogen?

Answer 16

+1

Question 17

What is the common oxidation number of fluorine?

Answer 17

-1

Question 18

What is the common oxidation number of Na+ or K+?

Answer 18

+1

Question 19

What is the common oxidation number of Mg2+ or Ca2+?

Answer 19

+2

Question 20

What is the common oxidation number of other halides?

Answer 20

-1

Question 21

In what special case, can hydrogen have an oxidation number of -1?

Answer 21

When in metal hydrides.

i.e. NaH or CaH(2)

Question 22

In what special case, can oxygen have an oxidation number of -1?

Answer 22

In peroxides.

i.e. H(2)O(2)

Question 23

In what special case, can oxygen have an oxidation number of +2?

Answer 23

When bonded to fluorine.

i.e. F(2)O

Question 24

In ions, what is a trick for determining oxidation numbers?

Answer 24

The sum of the oxidation numbers, is equal to the total charge.

Question 25

What do roman numerals mean in the use of iron(II) or iron(III)?

Answer 25

Iron(II) represents Fe2+ with oxidation number +2.

Iron(III) represents Fe3+ with oxidation number +3.

Question 26

What is oxidation?

Answer 26

The loss of electrons.

Question 27

What is reduction?

Answer 27

The gain of electrons.

Question 28

What is oxidation in terms of oxidation number?

Answer 28

An increase in oxidation number.

Question 29

What is reduction in terms of oxidation number?

Answer 29

A decrease in oxidation number.

Question 30

What is the word equation for the reaction of a metal with acid?

Answer 30

Metal + acid -> salt + hydrogen