(U1) Qualitative Tests Flashcards
What happens in a gas test with H2
Gives a ‘pop’ with a burning splint
What happens in a gas test with O2
Relights a glowing splint
What happens in a gas test with Cl2
Bleaches damp litmus/ universal indicator paper
(after turning it red)
What happens in a gas test with CO2
Bubble through limewater, limewater turns milky
What happens in a gas test with HCl (2)
- hot glass rod dipped in concentrated ammonia solution
- White smoke
What happens in a gas test with NH3 (4)
- hot glass rod dipped in concentrated Hydrochloric acid
- White smoke
Or
- Red litmus paper turns blue
- or damp ui paper turns blue
What colour does a Li+ ion produce in a flame test?
Crimson
What colour does a Na+ ion produce in a flame test?
Yellow / orange
What colour does a K+ ion produce in a flame test?
What colour through cobalt glass?
- Lilac
- pink
What colour does a Ca2+ ion produce in a flame test?
Brick red
What colour does a Ba2+ ion produce in a flame test?
Apple green
What colour does a Cu2+ ion produce in a flame test?
Green-blue
Outline how to conduct a flame test (3)
- Dip a nichrome wire in concentrated hydrochloric acid.
- Dip the wire into the solid metal salt.
- Hold the wire in the blue Bunsen flame and note the colour of the flame.
What colour precipitate does a Fe2+ ion cause when dissolved in sodium hydroxide/ammonia solution?
Green ppt
What colour precipitate does a Fe3+ ion cause when dissolved and added to sodium hydroxide/ammonia solution?
Red-brown ppt
