A race car is driven by professional driver at 99 miles . what is this speed in hours kilometers hours and kilometers minute

159.291 Kilometers/hour,  2.65485 Kilometers/minute

Explanation:

Miles to Kilometers - times by 1.609

Kilometers to Miles - divide by 1.609

99 miles to kilometers =

99 * 1.609  = 159.291

therefore, 159.291 km/hr

Kilometers/hours to Kilometers/minute - divide by 60

159.291/60 = 2.65485

therefore, 2.65485 km/min

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.