Zusammenfassung der Ressource
acids, bases + salts (2)
- neutralisation reactions
- when the H+(aq) ions from an acid react with the OH-(aq) ions
from an alkali, a neutralisation reaction occurs to form water
- e.g H+(aq) + OH-(aq) -> H20(l)
- acids
- when acids dissolve in water they produce
aqueous hydrogen ions, H+ (aq)
- e.g. hydrocholric acid
- alkalis
- when alkalis dissolve in water they produce
aqueous hydroxide ions, OH- (aq)
- e.g sodium hydroxide
- state symbols
- (s) - solid
- (l) - liquid
- (g) - gas
- (aq) - aqueous
(dissolves in water)
- making soluble salts
- when acids react with bases, a
salt and water are made:
- acid + metal oxide ->
salt + water
- acid + metal hydroxide ->
salt + water
- reactive metals
- acids will react with reactive metals,
such as magnesium and zinc, to make
a salt and hydrogen:
- acid + metal -> salt
+ hydrogen
- the hydrogen causes bubbling
during the reaction, this can be
detected using a lighted splint
- naming salts
- the name of the salt in a neutralisation
reaction can be predicted
- if the first part of the name is 'ammonium'
then the base used is ammonia, otherwise
it's the name of the metal in the base
- the second part of the name
comes from the base used:
- chloride - if hydrochloric acid is used
- nitrate - if nitric acid is used
- sulfate - of sulfuric acid is used
- making insoluble salts
- insoluble salts DO NOT
dissolve in water
- can be made by mixing appropriate
solutions of ions together
- e.g.silver chloride is insoluble, you
need soluble silver salt and a
soluble chloride salt to make it
- silver nitrate and sodium chloride are both
soluble, when you mix their solutions
together you make:
- soluble sodium nitrate
- insoluble silver chloride
- the silver chloride appears in tiny particles
suspended in the reaction mixture, it forms
a precipitate
- the precipitate can be filtered,
washed with water on the filter
paper, and then dried in an oven
- if you want to make an insoluble salt XY, mixing X
nitrate with sodium Y will always work
- in the e.g. X is silver and Y is chloride
- using precipitation
reactions
- they can be used to remove unwanted ions
in solutions, this is a useful way for treating
drinking water and waste water