Write down the structure of isomeric pentyl radicals. Name them by IUPAC system.

Name the type of isomers the following pair represents (with justification).

${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{CHO} \mathrm{and} {\mathrm{CH}}_3{\mathrm{COCH}}_3$

Name the type of isomers the following pair represents (with justification).

${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{CHO} \mathrm{and} {\mathrm{CH}}_3\mathrm{CH}\left(\mathrm{CHO}\right){\mathrm{CH}}_3$

Name the type of isomers the following pair represents (with justification).

${\mathrm{CH}}_3-\mathrm{CH}=\mathrm{CH}-{\mathrm{CH}}_3 \mathrm{and} {\mathrm{CH}}_2=\mathrm{CH}-{\mathrm{CH}}_2-{\mathrm{CH}}_3$

Name the type of isomers the following pair represents (with justification).

${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{NH}-{\mathrm{CH}}_2-{\mathrm{CH}}_3 \mathrm{and} {\mathrm{CH}}_3{\mathrm{NHCH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_3$

$0.6 \mathrm{g}$ of an organic compound gave on combustion $0.09 \mathrm{g}$ of ${\mathrm{H}}_2\mathrm{O}$ and $0.55 \mathrm{g}$ of ${\mathrm{CO}}_2$. Calculate the percentage composition of the compound if it contains only $\mathrm{C}, \mathrm{H}$ and oxygen.