Testing for ions

Question 1

What are the tests for positive ions

Answer 1

Flame test and precipitation reactions (sodium hydrodoxide)

Question 2

What colours do the flame turn the ions

Answer 2

Li - crimson
Na - yellow
K - lilac
Ca - orange-red
Cu - green

Question 3

What colours do the metals precipitates turn?

Answer 3

Ca - white
Cu - blue
Fe (II) - green
Fe (III) - brown
Al - white/colourless
Mg - white

Question 4

why does Al turn colourless

Answer 4

it redissolves in excess NaOH to form colourless

Question 5

How to test for carbonate ions

Answer 5

add a few drops of dilute acid and bubble any gas thats produced through limewater - cloudy = carbonates present

Question 6

How to test for halide ions

Answer 6

add dilute nitric acid followed by silver nitrate to solution. Chloride precipitate = white, bromide - cream, iodide - yellow

Question 7

how to test for sulfate ions

Answer 7

add dilute HCL and barium chloride - white precipitate = sulfate present