Testing for ions

Question 1

What are positive ions

Answer 1

Cations

Question 2

What are negative ions?

Answer 2

Anions

Question 3

How do you test for Halide ions?

Answer 3

Add silver nitrate first, then dilute ammonia, then concentrated ammonia

Question 4

What are the colour changes for each halide ion?

Answer 4

Chlorine- White Precipitate
Bromine- Cream Precipitate
Iodine- Yellow Precipitate

Question 5

How do you test for Sulphate ions?

Answer 5

Add Dilute HCl and Barium Chloride

Question 6

What are the observations for Sulphate ions?

Answer 6

White precipitate

Question 7

How do you test for Carbonate?

Answer 7

-Add strong Acid to carbonate
-Collect any gas and pass it through limewater

Question 8

What are the observations for Carbonate ions?

Answer 8

-Fizzing
-gas turns limewater cloudy

Question 9

How do you test for ammonium ions?

Answer 9

-Add sodium hydroxide
-Warm gently
-Test the gas with litmus paper

Question 10

What are the observations for ammonium ions?

Answer 10

-Ammonium turn red litmus paper blue
-Ammonium has distinctive smell
-Ammonium gas is hazardous