Qualitative Analysis- BGCSE

Which cations are responsible for the yellow, red and apple-green colors produced in a flame test?

• lithium, calcium, barium
• sodium, potassium, copper
• sodium, calcium, copper
• sodium, calcium, barium

Wha gas is produced when copper metal reacts with concentrated sulfuric acid and what is the test for the gas?

• hydrogen, makes a popping sound with a lighted splint
• carbon dioxide, turns limewater milky
• sulfur dioxide, turns blue litmus paper red
• oxygen, relights a glowing splint

Dilute sodium hydroxide is added to the solution of an unknown ion. The mixture is warmed to produce a gas that turns red litmus paper blue. What is the unknown ion?

• Ammonia
• ammonium
• carbonate
• nitrate

Which compound causes the blue-green color produced during an exploding fireworks display?

• calcium chloride
• copper chloride
• potassium chloride
• sodium chloride

When ammonium hydroxide solution is added to an unknown solution a green precipitate is fomed. Which ion is present?

• Cu 2+
• Fe 3+
• Fe 2+
• Zn 2+

Which compound forms a colored aqueous solution?

• calcium chloride
• Chromium chloride
• sodium hydroxide
• Potassium bromide