Acids, bases and salts Flashcards
what is an acid? what is their pH?
any substance that produce H+ (hydrogen) ions when added to water
their pH is >7
what is a base? what’s is their pH? which compounds are bases
bees are substances that can neutralise acids
their pH is from 8-14
metal oxides carbonates and hydroxides
what are alkalis? which compounds are alkali
all alkalis are bases, but they are bases that dissolve in water; soluble bases. they release OH- (hydroxide) ions when added to water
soluble hydroxides
what would happen if we put red litmus paper in an
acid?
alkali?
solution
acid- stays the same
alkali- turns blue
in a neutralisation reaction what do acids and bases react to form
they react to form water and a salt
what does an acid and metal carbonate react to form
they react to form water carbon dioxide and a salt
how is water formed in a neutralisation reaction
H+ + OH- -> H2O
what makes an acid a strong acid?
an acid with a higher concentration of H+ ions, fully ionised
what does ammonia dissolve in water to produce
an alkaline solution
what are 3 things you can react with acids to make a soluble salt
- metals
- insoluble bases
- alkalis
how do we get a soluble salt from reacting an acid with a metal
we react them together to produce hydrogen and a salt
how do we get a soluble salt from reacting an acid with an insoluble base
the base is added to the acid until no more will react and the excess solid is removed by filtration
how do we get a soluble salt from reacting an acid with an alkali
a neutralisation reaction happens and an indicator is used to see when they have completely reacted, forming water and a salt
when we obtain the salt solutions how can we make them into solid salts?
through crystalisation
how can we make insoluble salts?
using a precipitation method
mix 2 solutions containing soluble salts
this forms a precipitate
filter it to get the insoluble salt
