What is the formula of Acrolein?

Give the structures of the following compounds:
$(i)$ $4-$Nitropropiophenone
$(ii)$ $2-$Hydroxycyclopentanecarbaldehyde
$(iii)$ Phenyl acetaldehyde

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

What is the $IUPAC$ name of Mesityl oxide?

Find the correct molecular formulas for the following compounds: $(i)$ Propanone,$(ii)$ Propanal,and $(iii)$ $n$-Propanol.

Aldehydes are isomeric with: