Test

Question 1

Test for O_{2 (g)}

Answer 1

• relights a glowing splint

Question 2

Test for H_{2 (g)}

Answer 2

• makes a squeaky pop with a lighted splint

Question 3

Test for Na⁺

Answer 3

• clean platinum wire loop, dip in HCl, put in flame to clean, and wait for no coulour in flame.
• Yellow-orange flame

Question 4

Test for sulfates

Answer 4

• Add dilute HCl (to get rid of carbonate and sulfite ions as they give white precipitate as well)
• Add Barium chloride solution (BaCl₂)
• white precipitate means sulfate ions present in OG compound

Question 5

Test for NH₄⁺ (ammonium ions)

Answer 5

• Add sodium hydroxide
• Use damp red litmus paper to the gas given off, if it turns blue then ammonium ions present

Question 6

Test for carbonates

Answer 6

• add HCl
• if carbonates present CO₂ will be produced

Question 7

Test for I^-

Answer 7

• add dilute nitric acid (HNO3)
• add silver nitrate solution (AgNO3)
• yellow precipitate (silver iodide)

Question 8

Test for water (not pure)

Answer 8

• use anyhdrous copper(II) sulfate (white)
• add drops of water
• Anydrous copper(II) sulfate into hydrous copper(II) sulfate (blue)

Question 9

Test for Ca⁺

Answer 9

• clean platinum wire loop, dip in HCl, put in flame to clean, and wait for no coulour in flame.
• Brick-red flame

Question 10

Test for pure water

Answer 10

• Boils at 100 degrees
• freezes at 0 degrees

Question 11

Test for metal ions (Cu²⁺, Fe²⁺, Fe³⁺)

Answer 11

• add a few drops of sodium hydroxide
• Cu²⁺ = Blue
• Fe²⁺ = Sludgy Green
• Fe³⁺ = Reddish Brown

Question 12

Test for Li⁺

Answer 12

• clean platinum wire loop, dip in HCl, put in flame to clean, and wait for no coulour in flame.
• burns with crimson red flame

Question 13

Test for Cl_{2 (g)}

Answer 13

• Turns damp litmus paper white (bleach)

Question 14

Test for CO_{2 (g)}

Answer 14

• Bubble gas through limewater
• Turns limewater cloudy

Question 15

Test for Cl^-

Answer 15

• add dilute nitric acid (HNO₃)
• add silver nitrate solution (AgNO₃)
• white precipitate (silver chloride)

Question 16

Test for Br^-

Answer 16

• add dilute nitric acid (HNO3)
• add silver nitrate solution (AgNO3)
• cream precipitate (silver bromide)

Question 17

Test for K⁺

Answer 17

• clean platinum wire loop, dip in HCl, put in flame to clean, and wait for no coulour in flame.
• Lilac flame