Ion tests

Question 1

What is the result of performing a flame test, adding OH ions and SO₄ ions to Mg ions?

Answer 1

Flame test - no colour, bright white
OH ions - white precipitate
SO₄ ions - no effect

Question 2

What is the result of performing a flame test, adding OH ions and SO₄ ions to Ca ions?

Answer 2

Flame test - brick red
OH ions - white precipitate
SO₄ ions - no effect

Question 3

What is the result of performing a flame test, adding OH ions and SO₄ ions to Sr ions?

Answer 3

Flame test - crimson red
OH ions - no effect
SO₄ ions - white precipitate

Question 4

What is the result of performing a flame test, adding OH ions and SO₄ ions to Ba ions?

Answer 4

Flame test - green
OH ions - no effect
SO₄ ions - white precipitate

Question 5

Give the flame colours when Li, Na, K, Ca and Cu ions are burned

Answer 5

Li - crimson
Na - yellow
K - purple
Ca - brick red
Cu - blue

Question 6

What is the test for NH₄ ions?

Answer 6

Add few drops of NaOH
Warm gently
Test gas produced with damp red litmus paper - turns blue if NH₃ gas is present