Qualitative Test for Ions Flashcards
How is ammonia gas formed?
The heated reaction of aqueous ammonium ions and hydroxide ions.
How is the prescence of ammonia gas tested?
Using pH indicator paper
What colour what the indicator paper be if ammonia gas was present?
Blue
Why does ammonia gas turn indicator paper blue?
Ammonia gas is alkaline
What is added to a solid or solution when first testing for carbonate?
Nitric acid
After nitric acid is added to a solid or solution, what could be seen if the compund could have a carbonate ion?
Bubbles
To prove the bubbles are carbon dioxide, what should you do?
Bubble the gas through limewater?
What will happen if carbon dioxide is present?
A fine white ppt will form, making the lime water cloudy
What sulfate is very insoluble?
Barium Sulfate
What is the basis for the sulfate test?
The formation of a white ppt
When barium ions are added to an unknown compound, what state are the ions in?
Aqueous
What halide is very insoluble in water?
Silver halides
Howare ppt’s of silver halides formed?
Aqueous silver ions react with aqueous halide ions.
What colour ppt is Silver Chloride?
White
What colour ppt is Silver Bromide?
Cream
