The rate law for a reaction is found to be rate = k[X]4. By what factor does the rate increase if [X] is doubled?

The table describes how some substances were formed substance 19 description formed by boiling pure water formed by combining three hydrogen atoms to every nitrogen atom formed by adding 5 g of sugar to 1 l of water formed by compressing carbon under high pressure based on the given descriptions, which substance is most likely a mixture?

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.

Air can be considered a mixture. which statement does not explain why?