Select the correct answer. Given the law of conservation of energy, what happens when a 200°C iron bar is placed in thermal contact with a 30°C block of wood? A. Energy leaves the iron bar and enters the wood until the temperatures are equal. B. Energy leaves the wood and enters the iron bar until the temperatures are equal. C. All the energy from the iron bar is transferred to the wood. D. All the energy from the wood is transferred to the iron bar. Reset

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.