bases, acids and salts

Question 1

what colour is phenolphthalein indicator in an acid

Answer 1

colourless

Question 2

what colour is phenolphthalein indicator in an alkali

Answer 2

pink

Question 3

what colour is phenolphthalein indicator in a neutral solution

Answer 3

colourless

Question 4

what colour is red litmus in an acid

Answer 4

red

Question 5

what colour is red litmus in an alkali

Answer 5

blue

Question 6

what colour is red litmus in a neutral solution

Answer 6

red

Question 7

what colour is blue litmus in an acid

Answer 7

red

Question 8

what colour is blue litmus in an alkali

Answer 8

blue

Question 9

what colour is blue litmus in a neutral solution

Answer 9

blue

Question 10

what colour is methyl orange in an acid

Answer 10

red

Question 11

what colour is methyl orange in an alkali

Answer 11

yellow

Question 12

what colour is methyl orange in a neutral solution

Answer 12

orange

Question 13

ph and colour of a strong acid

Answer 13

0-2
red

Question 14

ph and colour of weak acids

Answer 14

3-6
3-4 orange
5-6 yellow

Question 15

ph and colour of neutral

Answer 15

7
green

Question 16

ph and colour of a weak alkali

Answer 16

8-11
8-9 green-blue
10-11 blue

Question 17

ph and colour of a strong alkali

Answer 17

12-14
12 dark blue
13-14 purple

Question 18

what can be used to indicate the strength of solutions

Answer 18

ph meter
universal indicator

Question 19

the higher the concentration of hydrogen ions the _________________________

Answer 19

lower the ph

Question 20

what type of ion is in acids

Answer 20

hydrogen

Question 21

acids dissolve in water to produce

Answer 21

hydrogen ions

Question 22

alkalis dissolve in water to produce

Answer 22

hydroxide ions

Question 23

when are alkalis formed

Answer 23

when metal oxides or hydroxide dissolve in water

Question 24

definition of a base

Answer 24

a metal oxide or metal hydroxide neutralises an acid to produce a salt and water

Question 25

strong acids and alkalis __________________________ in water

Answer 25

completely ionise

Question 26

weak acids and alkalis __________________________________ in water

Answer 26

partially ionise

Question 27

equations of neutralisation

Answer 27

H+(aq) + OH-(aq) -> H2O (l)

Question 28

are neutralisation reactions endothermic or exothermic

Answer 28

exothermic

Question 29

piece of equipment used to add acid in small amounts

Answer 29

burette

Question 30

definition of a salt

Answer 30

a salt is formed when some or all of the hydrogen ions in an acid are replaced by metal ions or ammonium ions

Question 31

hydrochloric acid

Answer 31

HCl

Question 32

sulfuric acid

Answer 32

H2SO4

Question 33

nitric acid

Answer 33

HNO3

Question 34

metal + acid

Answer 34

salt + hydrogen

Question 35

observation when a metal reacts with an acid

Answer 35

- fizzing - metal disappears - heat is produced

Question 36

acid + base

Answer 36

salt + water

Question 37

observations when and acids reacts with a base

Answer 37

- solid disappears - solution formed

Question 38

does the reaction between an oxide and acid produce heat

Answer 38

no

Question 39

acid + alkali

Answer 39

salt + water

Question 40

observations when and acid reacts with an alkali

Answer 40

- heat produced - solution formed

Question 41

acid + carbonate

Answer 41

salt + water + carbon dioxide

Question 42

how can we detect carbon dioxide + colour change

Answer 42

lime water colourless to milky

Question 43

observations when a acid and carbonate react together

Answer 43

- solid disappears - solution formed - heat is produced - fizzing

Question 44

does the reaction between a hydrogencarbonate and acid produce heat

Answer 44

no

Question 45

acid + ammonium

Answer 45

ammonium salt

Question 46

what colour are copper salts usually in solution

Answer 46

blue

Question 47

how to make copper sulfate crystals

Answer 47

1. warm 30cm3 of sulfuric acid gently 2. add small quantities of cupper(II) oxide and stir after each addition until no more reacts 3. filter to remove unreacted copper(II) oxide 4. evaporate half of the liquid 5. leave to cool and crystallise slowly. dry between 2 pieces of filter paper

Question 48

making sodium chloride crystals

Answer 48

1. measure out 25.0cm3 of hydrochloric acid into a conical flask 2. add 5 drops of phenolphthalein indicator 3. add sodium hydroxide from a burette until the colour changes from colourless to pink 4. the solution is now neutral but the indicator must be removed. add a large spatula of charcoal 5. heat the flask gently and swirl it for 5 minutes 6. filter the solution into an evaporating basin 7. evaporate half of the filtrate and allow to cool and crystallise slowly 8. filter the crystals and dry between two pieces of filter paper

Question 49

making copper sulfate crystals

Answer 49

1. measure out 25 cm3 of sulfuric acid into a small beaker 2. add the carbonate to the acid slowly and in small portions. when there is no more fizzing the acid has been neutralised 3. filter the liquid 4. evaporate half of the liquid and allow to cool and crystallise slowly 5. filter the crystals and dry between 2 pieces of filter paper

Question 50

what colour is copper carbonate

Answer 50

green

Question 51

what is used to distinguish the ph of strong acids

Answer 51

ph meter

Question 52

what is the unit of concentration

Answer 52

mol/dm3

Question 53

what is used to measure a)25cm3 of a liquid b)25.0 cm3 of liquid

Answer 53

a) measuring cylinder b) pipette/burette

Question 54

what colour is copper (II) oxide

Answer 54

black