Which of the above compounds form pairs of metamers?
Metamerism arises due to different alkyl chains on either side of the functional group in the molecule. In the given structures V and VI or VI and VII form a pair of metamers because they differ in carbon atoms on the either side of the functional group, i.e., O-atom.
Identify the pairs of compounds which are functional group isomers.
Two or more compounds having the same molecular formula but different functional groups are called functional isomers.
In the given structure I, II, III, IV represent alcohols as functional group, whereas V, VI, VII are ethers.
Hence, I and V, I and VI, I and VII, II and V, II and VI, II and VII, III and V, III and VI, III and VII, IV and V, IV and VI, IV and VII all are functional group isomers.
Identify the pairs of compounds that represents position isomerism.
When two or more compounds differ in position of substituent atom or functional group on the carbon skeleton, they are position isomers. In the given structures, I and II; III and IV, and VI and VII are position isomers.
26 Identify the pairs of compounds that represents chain isomerism.
When two or more compounds have similar molecular formula but different skeletons, these are referred to as chain isomer.
In the following structure
For testing halogens in an organic compound with $\mathrm{AgNO}_3$ solution, sodium extract (Lassaigne's test) is acidified with dilute $\mathrm{HNO}_3$. What will happen if a student acidifies the extract with dilute $\mathrm{H}_2 \mathrm{SO}_4$ in place of dilute $\mathrm{HNO}_3$ ?
On adding dilute $\mathrm{H}_2 \mathrm{SO}_4$ for testing halogens in an organic compound with $\mathrm{AgNO}_3$, white precipitate of $\mathrm{Ag}_2 \mathrm{SO}_4$ is formed. This will interfere with the test of chlorine and this $\mathrm{Ag}_2 \mathrm{SO}_4$ may be mistaken for white precipitate of chlorine as AgCl . Hence, dilute $\mathrm{HNO}_3$ is used instead of dilute $\mathrm{H}_2 \mathrm{SO}_4$.