C5 - Chemical Changes Flashcards
1
Q
Acid + metal ->
A
salt + hydrogen
2
Q
Acid + metal oxide ->
A
salt + water
3
Q
Acid + metal carbonate ->
A
salt + carbon dioxide + water
4
Q
Acid + metal hydroxide ->
A
salt + water
5
Q
Acid + base ->
A
salt + water
6
Q
Acid + alkali ->
A
salt + water
7
Q
D. Alkali?
A
A substance that has a pH value of more then 7
8
Q
RQ. Method for titration? (6)
A
- measure out vol. of alkali using bulb pipette (25cm3)
- put alkali into conical flask
- place acid in burette
- add indicator (Phenolphthalein/ methyl orange) to alkali
- add acid dropwise into flask unto neutralises (swirl)
- repeat to get precise results
9
Q
RQ. Safety measures for titrations? (2)
A
- goggles
- fill burette below face-height/on the floor
10
Q
RQ. Method for making a salt?
A
[ for v. reactive element ]
- Titration
- heat neutral solution in evaporating dish until half is evaporated
- let cool
- remove crystals and dry
11
Q
What method should you use for making a salt from…
- a non reactive metal
- a metal of medium reactivity
A
- combine metal and acid
- use metal hydroxide
12
Q
Ionic equation for neutralisation?
A
H+(aq)+OH-(aq) -> H2O(l)
13
Q
D. Base?
A
- Substance that neutralise acids (the oxide, hydroxide or carbonate of a metal that reacts with an acid and forms as salt as one of its products
14
Q
What ions are bases acceptors of?
A
H+ ions / proton acceptors
15
Q
What is a base that dissolves in water called?
A
an alkali
