Acids, Bases and Salts

Question 1

what is an indicator?

Answer 1

a substance that is one colour in acids and another in alkalis

Question 2

what is UI made up of?

Answer 2

a mixture of several different indicators

Question 3

what does litmus solution turn in different pHs?

Answer 3

acid - red
neutral - purple
alkaline - blue

Question 4

what does red litmus paper turn in different pHs?

Answer 4

acid - red
neutral - red (stayed the same colour as paper)
alkaline -blue

Question 5

what does blue litmus paper turn in different pHs?

Answer 5

acid - red
neutral - blue (stayed the same colour as paper)
alkaline - blue

Question 6

what does phenolphthalein turn in different pHs?

Answer 6

acid - colourless
neutral - colourless
alkaline - magenta pink

Question 7

what does methyl orange turn in different pHs?

Answer 7

acid - red
neutral - orange
alkaline -yellow

Question 8

what does UI turn in different pHs?

Answer 8

acid - red
neutral - green
alkaline - purple

Question 9

what is red litmus paper used to test for an why?

Answer 9

alkalines as it turns blue

Question 10

what is blue litmus paper used to test for and why

Answer 10

acids as it turns red

Question 11

what ion causes acidity?

Answer 11

hydrogen ion H+

Question 12

what does the pH scale measure?

Answer 12

the concentration of H+

Question 13

what type of scale is the pH scale?

Answer 13

logarithmic

Question 14

how much concentrated in H+ is ph 1 than ph 3?

Answer 14

100x

Question 15

what does pH stand for?

Answer 15

potenz (power in german) and H+

Question 16

what is the formula for phosphoric acid and the negative ion charge?

Answer 16

H3 PO4 and 3-

Question 17

what is the formula for ethanoic acid and the negative ion charge?

Answer 17

CH3COO H and 1-

Question 18

what is the formula for carbonic acid and the negative ion charge?

Answer 18

H2 CO3 and 2-

Question 19

how did the HCL (gas) dissolved in water react ?

Answer 19

UI - red
effervsence with all compounds
is electrially conductive

Question 20

how did the HCL (gas) dissolved in methylbenzene react?

Answer 20

UI - green
NVS
No electrical conductivity

Question 21

what hapnes to the HCL when dissolved in solvents?

Answer 21

it separates the H+ and the Cl- (as it is an acid)

Question 22

what is a Arrhenius acid?

Answer 22

and acid that dissolves in water to form H+ ions

Question 23

what does dissociate mean?

Answer 23

refers to how many acid molecules have been split apart into ions

Question 24

what does concentrated and dilute acids refer to?

Answer 24

refers to the amount of acid molecules dissolved in a certain amount of water

Question 25

what does strong and weak acids refer to?

Answer 25

refers to how many acid molecules have dissociated into ions

Question 26

examples of strong acids

Answer 26

HCL HNO3 H2SO4

Question 27

example of weak acid

Answer 27

ethanoic acid (CH3COOH)

Question 28

what symbol do you use to show an acid is weak?

Answer 28

⇌ = reversible reaction and so not fully complete

Question 29

what is the difference between the reactivity of strong and weak acids?

Answer 29

S.A are more reactive as they have fully dissociated acid molecules an so relatively has more H+ ions than W.A

Question 30

what is a base?

Answer 30

substances that can neutralise acids

Question 31

alkalis Vs bases

Answer 31

Alkalis - soluble bases (sub-group)

Question 32

what type of metal compounds are bases?

Answer 32

metal oxides and hydroxides

Question 33

what ion causes alkalinity?

Answer 33

OH- ions

Question 34

examples of strong alkalis

Answer 34

sodium and potassium hydroxide

Question 35

example of weak alkali

Answer 35

ammonia

Question 36

metal + acid →

Answer 36

salt + hydrogen metal + H+ → metal + H2

Question 37

metal oxide + acid →

Answer 37

salt + water 2H+ + O2- → H2O

Question 38

metal hydroxide + acid →

Answer 38

salt + water H+ + OH- → H2O

Question 39

metal carbonate + acid

Answer 39

salt + water + carbon dioxide 2H+ + CO3 2- → CO2 + H2O

Question 40

ammonia + acid →

Answer 40

ammonium salt H+ NH3 → NH4 1+

Question 41

what causes neutralisation?

Answer 41

when the H+ from acid and OH- from alkali combine to form H2O

Question 42

what experiment can be done to monitor the pH in a reaction? how much vinegar and water is used? how much lime is added each time? when does the spike in pH happen?

Answer 42

- calcium hydroxide and ethanoic acid (lime and vinegar) - 20ml each - 0.1g - at 0.9g of lime

Question 43

calcium hydroxide + ethanoic acid →

Answer 43

calcium ethanoate + water

Question 44

when would you use the excess base method?

Answer 44

to make a soluble salt out of an insoluble base and acid

Question 45

when would you use in titration

Answer 45

to make a soluble salt from a soluble base and an acid

Question 46

when would you use precipitation?

Answer 46

to make an insoluble salt using two soluble salts

Question 47

usually what substances are used in excess base method?

Answer 47

a metal oxide + acid

Question 48

usually what substances are used in titration method?

Answer 48

sodium or potassium hydroxide / ammonia + acid

Question 49

usually what substances are used in precipitation method?

Answer 49

_______ nitrate + sodium _______