Write the structures of the following compounds:
$(i)$ $\alpha$-Methoxypropionaldehyde
$(ii)$ $3$-Hydroxybutanal
$(iii)$ $2$-Hydroxycyclopentanecarbaldehyde
$(iv)$ $4$-Oxopentanal
$(v)$ Di-sec-butyl ketone
$(vi)$ $4$-Fluoroacetophenone

Give the name and structure of the following compounds:
$(i)$ Methanal $(ii)$ Ethanal $(iii)$ $2$-Methylpropanal $(iv)$ $3$-Methylcyclohexanecarbaldehyde $(v)$ $2$-Methoxypropanal $(vi)$ Pentanal $(vii)$ Prop-$2$-enal $(viii)$ Benzene-$1,2$-dicarbaldehyde $(ix)$ $3$-Bromobenzaldehyde

Which of the following is correctly matched according to their common names?

Which of the following aldehydes contains two $-CHO$ groups in a molecule?

What is the physical state of formaldehyde at room temperature?

Write the $IUPAC$ names of the following ketones and aldehydes. Wherever possible,give also common names.
$(i)$ $CH_{3}CO(CH_{2})_{6}CH_{3}$
$(ii)$ $CH_{3}CH_{2}CHBrCH_{2}CH(CH_{3})CHO$
$(iii)$ $CH_{3}(CH_{2})_{5}CHO$
$(iv)$ $Ph-CH=CH-CHO$
$(v)$ Cyclopentane ring attached to $-CHO$ group
$(vi)$ $PhCOPh$