How many functional groups are present in the following molecule?

How many secondary carbon and hydrogen atoms are present in the molecule $CH_3-CH(Br)-CH(Br)-CH_3$ respectively?

The number of $\sigma$ and $\pi$ bonds in propane$-1, 2, 3-$tricarboxylic acid is:

State True or False for the following statements:
$(i)$ Organic compound was first synthesized by $F$. Wohler.
$(ii)$ Berzelius stated that some mysterious force exists in living organisms.
$(iii)$ In $1828$,Wohler prepared an organic compound from an inorganic compound,at which time the vital force theory was accepted.
$(iv)$ Kolbe prepared acetic acid and Berthelot prepared methane.

Homologues have different

An organic compound $C_3H_6O$ does not give a precipitate with $2,4-$Dinitrophenylhydrazine reagent and does not react with metallic sodium. The compound is: