An unavoidable side reaction of alkyl halides with active metals which lowers the yield of Grignard reagents is called coupling.
2RX + Mg-----------> R-R + MgX2
Although the mechanism of the coupling process is not well understood, it is known that rate appears to depend on the square of the concentration of the halide. with this in mind, expalain the reason for the sequence of addition of the ether solution employed at the beginning of the formation of the Grignard reagent in the experimental procedure above.