Chemical Changes Flashcards
Why is a pipette used to measure alkali and burette used to measure acid?
Pipette measure fixed volume
Burette measures variable volume
Reaction between acids and bases is called
Neutralisation
Acid is a substance that forms? Water?
Aqueous solutions
H+ ions in water (ionises)
pH > 7
Alkali are…
Bases
Bases dissolve in water to form?
OH- ions
pH < 7
“acid + base” produces…
salt + water
Phenolphthalein, alkali —> acid
pink —-> colourless
Properties of weak acids
- Do not fully ionise in solution
- Only a small proportion of acid particles dissociate to release H+ ions
- Reversible reaction
- Less reactive than strong acids
Properties of Strong acids
- Ionises completely in water
- All acid particles dissociate to release H+ ions
- More reactive than weak acids
H+ ion concentration high mean…
A strong acid so
rate of reaction is faster.
Concentration is the measure of….
how much acid is in a certain volume of water
Reactivity is determined by…
how easily a metal loses an electron
Acid + Metal Carbonate ——>
Salt + Water + Carbon Dioxide
Acid + Metal ——->
Salt + Hydrogen
Zinc, Iron and copper can be extracted by reduction
Using Carbon this is because oxygen can only taken from metals which are less reactive than carbon,
