Chapter 4

Question 1

What are the four common acids?

Answer 1

HCL
H2SO4
HNO3
CH3COOH

Question 2

What is HCL?

Answer 2

hydrochloric acid

Question 3

What is H2SO4?

Answer 3

sulfuric acid

Question 4

What is HNO3?

Answer 4

nitric acid

Question 5

What is CH3COOH?

Answer 5

ethanoic acid

Question 6

What are the thee common alkalis?

Answer 6

NaOH
KOH
NH3

Question 7

What is NaOH?

Answer 7

sodium hydroxide

Question 8

What is KOH?

Answer 8

potassium hydroxide

Question 9

What is NH3

Answer 9

ammonia (base)

Question 10

What is a base?

Answer 10

Neutralises an acid to form a salt

Question 11

What is an acid?

Answer 11

Releases H+ ions in aqueous solution

Question 12

What is an alkali?

Answer 12

Is a base that dissociates in water, releasing OH- ions

Question 13

What does strong mean for an acid?

Answer 13

It fully and completely dissociated in aqueous solution

Question 14

What does weak mean for an acid?

Answer 14

Only partially dissociates in aqueous solution

Question 15

What is neutralisation?

Answer 15

Is when H+ ions react with a base to form a salt and water. (e.g H+ + OH- to make H2O)

Question 16

What does acid + alkali make?

Answer 16

Salt + water

Question 17

What does acid + metal oxide/hydroxide?

Answer 17

Salt + water

Question 18

What does acid + metal carbonate?

Answer 18

Salt + water + carbon dioxide

Question 19

What is a disproportionation reaction?

Answer 19

It is when one atom both oxidise and reduction in one reaction.

Question 20

What does oxidation mean?

Answer 20

Is the loss of electrons and corresponds to an increase in oxidation numbers for an element.

Question 21

What does reduction mean?

Answer 21

Is the gain of electrons and corresponds to an decrease in oxidation numbers for an element.

Question 22

What is an example equation for oxidation?

Answer 22

Fe2+ to Fe3+ + e-

Question 23

What is an example equation for reduction?

Answer 23

Cu2+ + 2e- to Cu3+

Question 24

What happens in a redox reaction?

Answer 24

Involve reduction and oxidation of species

The electrons gained + lost must be balanced.

Question 25

What is a standard solution?

Answer 25

Is a solution of known concentration.

Question 26

How to prepare a 250cm3 of standard solution?

Answer 26

1. Calculate, then weigh out the required amount of solid.
2. Dissolve the solid in a beaker with a small amount of distilled water.
3. Transfer to a 250cm3 volumetric flask, rinse the beaker into the flask and make up to the graduation line in distilled water
4. Invert the flask slowly ensuring the missing is even.

Question 27

How to determine concentration of a acid in a titration?

Answer 27

• determine the mole of salt in the 500cm3 solution and hence in 25cm3 - n=m/mr then divided to find 25cm3
• calculate the moles of acid required to neutralise it - ratio
• determine the concentration of acid - c=n/v

Question 28

What is the oxidation number?

Answer 28

Shows the number of electrons in an atom which has lost or gained electrons.

Question 29

What is the sum of oxidation numbers in a compound?

Answer 29

The charge on its compound

Question 30

What is the oxidation number of oxygen?

Answer 30

Normally -2, but -1 in peroxide (e.g H2O2) and +2 in F2O

Question 31

What is the oxidation number of halogens?

Answer 31

-1

Question 32

What is the oxidation number of hydrogen?

Answer 32

normally +1 but -1 in metal hydroxide (e.g NaH)

Question 33

What is the oxidation number of group 1?

Answer 33

+1

Question 34

What is the oxidation number of group 2?

Answer 34

+2

Question 35

What is the oxidation number in elements in their natural form?

Answer 35

0