C3.3 - types of chemical reactions

Question 1

what is neutralisation?

Answer 1

the reaction between acids and a base/alkali to form a salt and water only

Question 2

does the pH of the solution during neutralisation change?

Answer 2

yes, depending on the concentration of acid/alkali

Question 3

what salt is produced when copper oxide powder neutralises sulfuric acid?

Answer 3

copper sulfate

Question 4

what are the products produced during the neutralisation of:

sodium hydroxide + hydrochloric acid ->

Answer 4

sodium chloride + water

Question 5

what is the equation during the reaction of an acid and a metal carbonate?

Answer 5

acid + carbonate -> salt + water + carbon dioxide

Question 6

what are the products of the following reaction:

hydrochloric acid + calcium carbonate ->

Answer 6

calcium chloride + water + carbon dioxide

metal carbonate

Question 7

what is the word equation during the reaction of a metal oxide and an acid?

Answer 7

Acid + oxide → salt + water

Question 8

what are the products of the following reaction:

hydrochloric acid + magnesium oxide ->

Answer 8

magnesium chloride + water.

Question 9

what is the word equation of the reaction between a metal hydroxide and acid?

Answer 9

hydroxide + acid -> salt + water

Question 10

what are the products of the following reaction:

hydrochloric acid + sodium hydroxide →

Answer 10

sodium chloride + water

Question 11

what happens during neutralisation in solution?

Answer 11

• acidic solutions contain H+ ions (hydrogen)
• alkaline solutions contain OH- ions (hydroxide)
• they both react together and produce water

Question 12

what is a redox reaction?

Answer 12

a reaction where reduction and oxidation happens at the same time

Question 13

what is reduction in terms of oxygen?

Answer 13

loss of oxygen

Question 14

what is oxidation in terms of oxygen?

Answer 14

gain of oxygen

Question 15

looking at the following equation what is the oxidising and reducing agent and why?

aluminium + iron oxide -> aluminium oxide + iron

Answer 15

iron oxide is the oxidising agent as is oxidises aluminium to aluminium oxide

aluminium is the reducing agent as it reduces iron oxide to iron

Question 16

what is the mnemonic for remembering oxidation/reduction/ electrons etc.?

Answer 16

OIL RIG

• > oxidation is loss
• > reduction is gain

Question 17

do redox reactions always have to involve oxygen?

Answer 17

no, it can just be a loss/gain of electrons

Question 18

what is an acid? (in terms of what it releases when dissolved in water)

Answer 18

a substance which releases hydrogen ions when dissolved in water

Question 19

what makes a solution acidic?

Answer 19

hydrogen ions

Question 20

what is a base?

Answer 20

a substance that can neutralise acids

Question 21

what does an alkali release when dissolved in water?

Answer 21

OH- ions

Question 22

what makes a solution alkaline?

Answer 22

hydroxide ions

Question 23

what does pH < 7 mean?

Answer 23

acidic

Question 24

what does pH = 7 mean?

Answer 24

neutral

Question 25

what does pH > 7 mean?

Answer 25

alkaline

Question 26

what do you use to show the pH of a solution?

Answer 26

• universal indicator

- pH meter

Question 27

what are carbonates?

Answer 27

ionic compounds that contain the carbonate ion (CO3 2-)

Question 28

what do carbonates form when react with acids?

Answer 28

salt + water + carbon dioxide

Question 29

what is produced when a metal reacts with an acid?

Answer 29

salt + hydrogen

Question 30

what salt is produced when magnesium and hydrochloric acid reacts together?

Answer 30

magnesium chloride

Question 31

why does a piece of magnesium ribbon appear to have dissolved if placed into acid?

Answer 31

• hydrogen is released as bubbles

- salt magnesium chloride is formed

Question 32

what is a dilute acid?

Answer 32

an acid which contains a low ratio of acid to volume of solution

Question 33

what is a concentrated acid?

Answer 33

an acid which contains a high ratio of acid to volume of solution

Question 34

what is a weak acid?

Answer 34

acids that partially ionise (only a small fraction of their molecules release H+ ions)

Question 35

what is a strong acid?

Answer 35

acids that fully ionise (all molecules release H+ ions)

Question 36

what does a pH titration curve show?

Answer 36

the effect on pH by changing the hydrogen ion concentration during a neutralisation reaction

Question 37

What needs to be done before measuring pH with a pH meter?

Answer 37

Calibration to get accurate results :
Wash the pH probe with water, then put it into a calibration buffer.
Adjust the reading to match the pH of the buffer solution.

Question 38

When measuring pH with pH meter what needs to be done?

Answer 38

Wash probe with water, put into solution, record reading

Wash probe with water between each measurement to ensure not contaminated with previous sample

Question 39

How pH changes with hydrogen ion concentration?

Answer 39

As concentration of H+ ions increase by a factor of 10, the pH of a solution decreases by 1

Question 40

For a given volume of solution, the greater the amount of _ it contains, the greater it’s concentration.

Answer 40

Solute

Question 41

Difference between acid strength and concentration

Answer 41

Acid strength - idea that acid strength is a measure of the degree of ionisation of the acid

Concentration - idea of number of moles (of acid) in 1 dm3