Acids and Alkalis y9 Flashcards
titration definition
the sow addition of one solution with a known concentration (the titrant) to the known volume of another solution of unknown concentration until the reaction reaches neutralization
titration reactants and products
soluble salt (acid) + soluble salt (alkali) —–> soluble salt + water
excess base definition
the amount of acid or base that must be added to a solution to return the pH back to neutral
excess base reactants and products
insoluble base (oxide or hydroxide) + acid —–> soluble salt + water
precipitation definition
precipitation occurs in an aqueous solution when a liquid forms an insoluble solid known as a “precipitate”
precipitation reactants and products
soluble salt + soluble salt —–> insoluble salt + soluble salt
titration experiment
fill a burette with acid and note the starting volume
slowly add the acid from the burette to the alkali in the conical flask
swirl the conical flask to stir
stop adding the acid when the appropriate colour change of the indicator happens
excess base experiment
react excess of solid oxide/ hydroxide with acid
stir
filter
evaporate until crystals form on a glass rod
leave to cool
filter crystals
pat dry
precipitation experiment
mix two solutions
filter
wash residue with water
leave to dry in a warm place
pat dry with filter paper
Acids are a source of…
hydrogen atoms
Alkalis are a source of…
hydroxide atoms
what is an aqueous solution?
a solution in which the solvent is liquid water - a precipitate is sometimes formed
What ionic compounds are soluble?
- common sodium, potassium and ammonium compounds
- all nitrates
- ## common chlorides (except for silver and lead (II))
what ionic compounds are insoluble?
- common carbonates (except for sodium, potassium and ammonium)
- common hydroxides (except for sodium, potassium and calcium)
