Draw the structure of the xylene that will give only two mononitro derivatives.

Structure of meta xylene has been shown below.

Explanation:

Xylene is dimethyl substituted benzene.Among three possible isomers of xylene, only meta substituted xylene gives mononitration product at two different position.Mononitration is possible in meta-xylene due to synergistic effect of two o/p-orienting methyl groups.Synergistic effect refers that o/p-directing power of two methyl groups act together at a particular position.Structure of xylene as well as their two possible mononitro derivatives has been shown below.

The flat sheet will completely rust before the iron cube. Since they both have the same volume, the flat sheet has more surface area than the small cube. This means more particles are exposed on the flat sheet that can react in a chemical reaction.