test for ions

Question 1

ammonium ions (NH4 +)

Answer 1

add sodium hydroxide
ammonia gas produced
heat in water bath
place damp red litmus in mouth of test tube - should turn blue

Question 2

carbonate ions (CO3 2-)

Answer 2

add dilute nitric acid

effervescence occurs then carbonate ions present

Question 3

sulfate ions (SO4 2-)

Answer 3

add barium nitrate

a white precipitate should be formed

Question 4

chloride ions

Answer 4

add silver nitrate
white precipitate should be formed
soluble in both dilute and concentrated ammonia

Question 5

iodide ions

Answer 5

add silver nitrate
yellow precipitate should be formed
insoluble in both concentrated and dilute ammonia

Question 6

bromide ions

Answer 6

add silver nitrate
cream precipitate formed
soluble in concentrated ammonia insoluble in dilute ammonia

Question 7

order of tests for ions

Answer 7

carbonate
sulfate
then halide - silver nitrate & ammonia etc.

Question 8

colours of halides in cyclohexene

Answer 8

chlorine - pale green
bromine - orange
bromine - purple