Pure Chem Sec 3 : Qualitative Analysis

Why is nitric acid added before adding aqueous silver nitrate to test for chloride ions?

• To remove chloride ions.

• To acidify the solution

• To supply nitrate ions

• To remove interfering ions, such as carbonate.

Tags

NGSS.HS-PS1-2

NaOH is added to an unknown solution. A reddish-brown ppt forms. The formula of the ion is:

• Fe²⁺

• Fe³⁺

• Cu²⁺

• Cl^-

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-1

NaOH is added to an unknown solution. A green ppt forms. The formula of the ion is:

• Fe²⁺

• Fe³⁺

• Cu²⁺

• Na⁺

Tags

NGSS.HS-PS1-2

NaOH is added to an unknown solution. A strong smell is given off after warming. The formula of the ion is:

• Cl^-

• Br₂

• NH₄⁺

• I^-

when ionic compound dissolves in water,

• it break down into cations and anions amd become free mobile ions.

• it remains in the solid state

• the ions vibrates at its fixed position

Which is a positive test result for presence of oxygen gas?

• Makes a squeaky pop with a lit splint
• Relights a glowing splint
• Bleaches damp litmus paper
• Turns limewater milky

What is a positive test result for carbon dioxide gas?

• Gave a white precipitate with limewater

• Relights a glowing splint
• Makes a squeaky pop with a splint
• Bleaches damp litmus paper

what is the result for the positive test for Chlorine gas?

• Bleaches damp litmus paper
• Makes a squeaky pop with a lit splint
• Relights a glowing splint
• Turns limewater milky

When we test for nitrate, which gas is evolved ?

• Nitrogen Dioxide
• Ammonia
• Ammonium
• Nitrogen trioxide

NaOH + Unknown solution + aluminium foil - warm the reaction.
Which anion are we testing for ?

• Nitrite (NO₂^-)
• Nitrate (NO₃^-)
• Sulfite (SO₃^2-)

• Sulfate (SO₄^2-)