2.3) The amide proton of N-methyl formamide (HCONHCH3) appears at 8.0 ppm in organic (nonexchanging) solvents. In water if this proton exchanges with the water protons at rates of 4x10-1/sec at pH 4 and 1x106 /sec at pH 10. Calculate the chemical shifts of the amide proton of 0.010 M N-methyl formamide in water at pH 4 and 10 for a proton NMR spectrometer operating at 600 MHz. Use 5.0 ppm for the chemical shift of the water protons.

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.