Testing for Ions and Precipitates

The video tutorial covers qualitative analysis, focusing on tests for carbonates, halides, nitrates, sulfates, sulfites, and various metal ions. It explains the procedures and observations for each test, such as effervescence for carbonates and precipitate colors for halides. The tutorial also includes practical applications and questions to reinforce understanding.

What observation indicates the presence of carbonate ions when an acid is added?

• Effervescence or fizzing

• No visible change

• Formation of a white precipitate

• Change in color to blue

Which reagent is used to test for the presence of halide ions?

• Ammonium chloride

• Barium chloride

• Silver nitrate

• Sodium hydroxide

What gas is released when testing for nitrates using sodium hydroxide and aluminum foil?

• Oxygen

• Hydrogen

• Carbon dioxide

• Ammonia

What is the result of adding sodium hydroxide to a solution containing aluminum ions?

• Blue precipitate, insoluble in excess

• Green precipitate, insoluble in excess

• White precipitate, soluble in excess

• No precipitate formed

How can you confirm the presence of ammonium ions in a solution?

• Add barium nitrate and observe a white precipitate

• Add sodium hydroxide and warm gently to release a gas that turns red litmus paper blue

• Add silver nitrate and observe a cream precipitate

• Add hydrochloric acid and observe effervescence

What color precipitate is formed when sodium hydroxide is added to copper ions?

• Light blue

• Green

• Red-brown

• White

Which metal ion gives a red-brown precipitate with sodium hydroxide?

• Iron(II)

• Iron(III)

• Copper

• Zinc

What is the observation when excess ammonia is added to a solution containing zinc ions?

• No precipitate formed

• White precipitate, insoluble in excess

• White precipitate, soluble in excess

• Green precipitate, insoluble in excess

In a problem-solving scenario, what indicates the presence of iodide ions?

• White precipitate with silver nitrate

• Yellow precipitate with silver nitrate

• Cream precipitate with silver nitrate

• No precipitate with silver nitrate

What pH value would you expect for a neutral solution in a qualitative analysis test?

• pH 2

• pH 7

• pH 13

• pH 5