Dilute hydrochloric acid is added to a colourless solution. Bubbles appear immediately and this gas turns limewater cloudy. What ion was present in the solution?

A mystery solution contains a sodium halide. Dilute nitric acid is added, and then some silver nitrate solution. A cream precipitate is formed, which dissolves in dilute ammonia solution. What halide ion is present?

Bromine water is added to a solution of an organic compound and instantly turns from orange to colourless. Which functional group is present in the compound?

A solution of an organic compound is treated with Tollen's reagent and warmed. A silver mirror forms. Which functional group is present in the molecule?

In a chemical test effervescence is observed. The student wants to prove that the gas is carbon dioxide, so bubbles a sample through......

To prove a compound is an aldehyde, a student tests using Fehling's solution. A colour change is observed from......

Which of the following substances will change potassium dichromate from orange to green when warmed with dilute sulfuric acid? Select all that apply.