C3.3: Types Of Chemical Reactions

Question 1

What is a redox reaction?

Answer 1

A reaction where oxidation and reduction occurs at the same time

Question 2

What is oxidation?

Answer 2

Gain of oxygen
Loss of electrons

Question 3

What is reduction?

Answer 3

Loss of oxygen
Gain of electrons

Question 4

What is a reducing agent?

Answer 4

A substance that gains electrons by the end of the reaction

Question 5

What is an oxidising agent?

Answer 5

A substance that loses/donates electrons by the end of the reaction

Question 6

What is an acid?

Answer 6

A substance that forms acidic solutions in water
Releases H+ ions in water to make an aqueous solution

Question 7

What is an alkali?

Answer 7

Forms alkaline solutions in water
Release OH- ions in water to make an aqueous solution
Hydroxide ions make the solution alkaline

Question 8

What must pH be in order to define a substance as acidic?

Answer 8

Less than 7
The more closer to 1 it is, the more acidic

Question 9

What must pH be in order to define a substance as alkaline?

Answer 9

Greater than 7
The more greater to 7 it is, the more alkalinic it is

Question 10

What must pH be in order to define a substance as neutral?

Answer 10

Must equal 7

Question 11

How can you use a universal indicator to calculate the pH of a substance?

Answer 11

Dip a clean glass rod into a solution
Transfer 1 drop of solution to a piece of universal indicator on a white tile
Wait 30 seconds for colour to develop, then match te colour onto the chart

Question 12

How can you use a pH probe to calculate the pH of a substance?

Answer 12

Wash the pH probe with distilled water
Put the end of the probe into the solution
Record the reading on the pH meter

Question 13

What colour will a pH level of 1 be when you add a universal indicator?

Answer 13

red

Question 14

What colour will a pH level of 0 be when you add a universal indicator?

Answer 14

Dark red

Question 15

What colour will a pH level of 2 be when you add a universal indicator?

Answer 15

Light red

Question 16

What colour will a pH level of 3 be when you add a universal indicator?

Answer 16

Orange

Question 17

What colour will a pH level of 4 be when you add a universal indicator?

Answer 17

Light orange

Question 18

What colour will a pH level of 5 be when you add a universal indicator?

Answer 18

Yellow

Question 19

What colour will a pH level of 6 be when you add a universal indicator?

Answer 19

Light green

Question 20

What colour will a pH level of 7 be when you add a universal indicator?

Answer 20

Green

Question 21

What colour will a pH level of 8 be when you add a universal indicator?

Answer 21

Turquoise

Question 22

What colour will a pH level of 9 be when you add a universal indicator?

Answer 22

Sky blue

Question 23

What colour will a pH level of 10 be when you add a universal indicator?

Answer 23

Light blue

Question 24

What colour will a pH level of 11 be when you add a universal indicator?

Answer 24

Pastel blue

Question 25

What colour will a pH level of 12 be when you add a universal indicator?

Answer 25

Darker pastel blue

Question 26

What colour will a pH level of 13 be when you add a universal indicator?

Answer 26

Blue

Question 27

What colour will a pH level of 14 be when you add a universal indicator?

Answer 27

Navy blue

Question 28

What is neutralisation?

Answer 28

The reaction between an acid and a base to form a salt and water only

Question 29

What is the word equation for neutralisation?

Answer 29

Acid + base —> salt + water

Question 30

What is the word equation for the reaction between an acid and a carbonate?

Answer 30

Acid + carbonate —> salt + water + carbon dioxide

Question 31

What is the word equation for the reaction between an acid and a metal?

Answer 31

Acid + metal —> salt + hydrogen

Question 32

When does a solution form?

Answer 32

A solution forms when a solute dissolves into a solvent The greater amount of solute, the more concentrated

Question 33

What is a dilute acid?

Answer 33

Low ratio of acid to volume ratio

Question 34

What is a concentrated acid?

Answer 34

High ratio of acid to volume ratio

Question 35

What happens when an acid is dissolved into water?

Answer 35

Acid separates into ions

Question 36

What is a strong acid?

Answer 36

Acid molecules completely break apart into ions Fully ionised All molecules release H+ ions

Question 37

What is a weak acid?

Answer 37

Acid molecules partially break apart into ions Partially ionised Only a small fraction of molecules release H+ ions

Question 38

How will the pH be if there is a higher concentration of H+ ions in an acidic solution?

Answer 38

Lower the pH

Question 39

How will the pH be if there is a higher concentration of OH- ions in an alkalinic solution?

Answer 39

Higher the pH