Tests For Ions

Question 1

Colour of sodium in burner

Answer 1

Yellow

Question 2

Colour of potassium in a burner

Answer 2

Lilac

Question 3

Colour of calcium in burner

Answer 3

Red

Question 4

Colour of barium in a burner

Answer 4

Green

Question 5

Calcium + NaOH

Answer 5

White precipitate

Question 6

Copper II 2+ and NaOH

Answer 6

Blue precipitate

Question 7

Iron II 2+ and NaOH

Answer 7

Green precipitate

Question 8

Iron 3 and NaOH

Answer 8

Brown

Question 9

Aluminium and NaOH

Answer 9

White and then clear as it redid solves with excess NaOH form colourless solution

Question 10

Mg and NaOH

Answer 10

White

Question 11

Test for carbonate

Answer 11

Acid + carbonate bubbles off CO2 which makes limewater cloudy

Question 12

Test for chloride/ bromide / iodide

Answer 12

Add dilute nitric acid then silver nitrate solution

Question 13

Test for sulphate

Answer 13

Add HCl then barium chloride solution

Question 14

If halide test is positive for chlorine

Answer 14

White precipitate - silver chloride

Question 15

If halide test is positive for bromide

Answer 15

Cream - silver bromide

Question 16

Halide test positive for iodide

Answer 16

Yellow precipitate - silver iodide

Question 17

Temporary hard water

Answer 17

Hydrogen carbonate decomposes to make insoluble calcium carbonate - scale

Question 18

Remove both hard water

Answer 18

1) sodium carbonate added and mg and ca ions react with carbonate ions - insoluble precipitate
2) ion exchange columns - switch mg or ca as water runs through with other ions such as sodium or hydrogen which they have a lot of.

Question 19

Colour of lithium in burner

Answer 19

Crimson