Identification Of Ions Flashcards
What are ionic compounds composed of?
Positive cations and negative anions
What is qualitative analysis in chemistry?
The identification of cations and anions present in unknown ionic compounds
What color indicates the presence of copper(1) ion?
Blue
What is the purpose of identifying cations?
To determine the identity of metal ions in a compound
What is the general ionic equation for metal ion reactions with hydroxide?
M^+(aq) + nOH^-(aq) → M(OH)n(s)
What happens when sodium hydroxide solution is added to a solution containing metal ions?
A precipitate will form, except for alkali metal ions
What does the color of the precipitate indicate?
The identity of the metal cation present in a solution
What are the exceptions to the solubility of hydroxides?
Ammonium hydroxide and hydroxides of alkali metals
What types of hydroxides do not react with sodium hydroxide?
Calcium hydroxide, iron(II) hydroxide, iron(III) hydroxide, copper(II) hydroxide
What are amphoteric hydroxides?
Hydroxides that react with sodium hydroxide, such as aluminium hydroxide, zinc hydroxide, and lead(II) hydroxide
What gas is produced when ammonium ions react with hydroxide ions?
Ammonia gas
What happens when ammonium salts are heated in a dry test tube?
Ammonia gas is produced
What is the role of aqueous ammonia in cation identification?
It contains hydroxide ions that form precipitates with metal ions
Which hydroxides do not react with ammonium hydroxide?
Aluminium hydroxide, lead(II) hydroxide, iron(II) hydroxide, iron(III) hydroxide
Which hydroxides react with ammonium hydroxide?
Zinc hydroxide and copper(II) hydroxide
How can you distinguish between Al^3+ and Pb^2+ ions?
By adding potassium iodide solution; Pb^2+ produces a bright yellow precipitate
Fill in the blank: Ammonium hydroxide is ______, therefore no precipitate forms.
soluble
What is the color of the precipitate formed by Pb^2+ with potassium iodide?
Bright yellow
True or False: Zinc hydroxide is insoluble in excess ammonium hydroxide.
False
