Six-mark questions are extended open response questions. These require longer answers than the structured questions that have fewer marks. It is wise to plan your answer first by making some notes.

THE veteran professor emeritus of the Federal Technical University of Zurich would seem to be devoting his well-earned leisure almost exclusively to the emendtion of those monumental treatises on ...

Paper-based materials must include an alkali reserve of at least 2% calcium carbonate (CaCO3). The alkali reserve has the ability to capture acids that may be in the air, the photograph, or in the ...

Answer: (i) The carbonyl group of aldehydes and ketones is reduced to the CH 2 group on treatment with zinc amalgam and concentrated hydrochloric acid. (ii) Aldehydes which do not have an α-hydrogen ...