Chemical tests for ions

Question 1

Flame tests

Answer 1

• Lithium, Li+, Red
• Sodium, Na+, Orange
• Potassium, K+, Lilac
• Calcium, Ca 2+ Brick Red

Question 2

How do Flame tests work?

Answer 2

• Clean platinum wire with concentrated acid

- Add compound roaring flame

Question 3

Sodium hydroxide tests

Answer 3

• Fe 2+, Green precipitate
• Fe 3+, Brown precipitate
• Cu 2+, Blue precipitate

Question 4

How to sodium hydroxide tests work?

Answer 4

• Add sodium hydroxide to a solution of the compound

- Sodium hydroxide reacts with ammonium ions to form ammonia gas which is an alkaline and turns red litmus paper blue.

Question 5

Halide tests

Answer 5

• Cl (minus)
• Br (minus)
• I (minus)

Question 6

How do Halide tests work?

Answer 6

• Add nitric acid to react carbonate impurities

- add silver nitrate

Question 7

Sulfate Test

Answer 7

• add hydrochloric acid to react

- test gas produced with limewater, goes cloudy