Paragraph for Questions 15 and 16
P and Q are isomers of dicarboxylic acid CX4HX4OX4. Both decolorize BrX2/HX2O. On heating, P forms the cyclic anhydride. Upon treatment with dilute alkaline KMnOX4, P as well as Q could produce one or more than one from S, T and U.
In the following reaction sequences V and W are, respectively