A student left some alkyl halides (RCl and RBr) in an open container for several minutes. What happened to the composition of the halide mixture during that time?
1 Answer
The decrease in proportion of chloride in composition of the mixture with time will happen.
Explanation:
The two alkyl halides have got same alkyl group R but they differ in halogen atom, one containing chlorine and another bromine , So molecular mass of bromide will be greater than that of chloride. For this reason the vander waal's force operative in bromide molecules will be higher than that of chloride molecules and this will provide more molecular association. So greater thermal KE will be needed to convert them to gaseous state from liquid state. This means they will have higher boiling point i.e. less volatile.
So if they are in liquid state at normal temperature and pressure ,the chloride molecule will escape more as vapor. Again if they are in gaseous state under normal pressure and temperature the rate of diffusion of chloride ( also the rate of escape) will be higher as the rate of diffusion is inversely proportional to square root of molecular mass.
So the result of keeping the mixture in open container will be the decrease in proportion of chloride in the composition of halide mixture as time goes by.
