Test for ions

Question 1

Group 2 ions test

Answer 1

• Flame test
• Dip nichrome wire loop in conc HCl
• Dip loop in unkown compound
• Hold loop in flame
• Observe colour change

Question 2

What are the colour changes of group 2 ions?

Answer 2

• Ca²⁺ - brick red
• Sr^{<strong>2+</strong>} - red
• Ba^{<strong>2+</strong>} - pale green

Question 3

Test for ammonium ions

Answer 3

• Damp red litmus paper (so ammonia gas dissolves) - blue
• Add dilute sodium hydroxide + gently heat w/ substance containing ammonium ions - ammonia given off

Question 4

Test for sulfates

Answer 4

• Add dilute HCl
• Add barium chloride sol
• White ppt - barium sulfate formed

Question 5

Test for hydroxides

Answer 5

• Red litmus paper
• Turns blue

Question 6

Test for carbonates

Answer 6

• Add HCl (sol will fizz)
• Test for CO₂ = limewater test