Can someone help me with this organic chemistry question about halides?

Question

The question is, "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?" Not quite sure how to figure this one out...any help will be greatly appreciated!

Answer 1

Alkyl halides are not very reactive to air/water but if they were relatively low-molecular weight halides like CH2Cl2, CHBr3 etc some of the material may have evaporated changing the ratio of the mixture and total mass.