Analysing Substances Flashcards
What can flame tests be used to identify?
Metal ions
Which 5 metal ions produce coloured flames?
Lithium, sodium, calcium, potassium, barium
What colour flame do lithium compounds have?
Crimson
What colour flame do sodium compounds have?
Yellow
What colour flame do potassium compounds have?
Lilac
What colour flame do calcium compounds have?
Red
What colour flame do barium compounds have?
Green
Which 3 metal ions form white precipitates with sodium hydroxide solution?
Aluminium, calcium, magnesium
What happens to an aluminium hydroxide precipitate when excess sodium hydroxide solution is added?
It dissolves
What do copper (ii), iron (ii) and iron (iii) form with sodium hydroxide solution?
Coloured precipitates
What colour precipitate does copper (ii) form with sodium hydroxide solution?
Blue
What colour precipitate does iron (ii) form with sodium hydroxide solution?
Green
What colour precipitate does iron (iii) form with sodium hydroxide solution?
Brown
What do carbonate ions react with to form carbon dioxide?
Dilute acids
What substance does carbon dioxide produce a white precipitate in?
Lime water
What do halides form precipitates with?
Silver nitrate solution, in the presence of dilute nitric acid
What colour precipitate does silver chloride form?
White
What colour precipitate does silver bromide form?
Cream
What colour precipitate does silver iodide form?
Yellow
What do sulfate ions form precipitates with?
Barium chloride solution, in the presence of dilute hydrochloric acid
What colour precipitate do sulfate ions have?
White
The volumes of acid and alkali solutions can be measured by…
Titration using a suitable indicator
If the concentration of one reactant is known, the results of the titration can be used to find…
The concentration of the other reactants
