1) Draw all the monochlorinated derivatives of 2,2,3,3-tetramethylbutane that are skeletal isomers of one another. To make a monochlorinated derivative of a compound, replace one H atom in the compound with Cl.
2) Draw all the monochlorinated derivatives of 2,3-dimethylbutane that are skeletal isomers of one another. To make a monochlorinated derivative of a compound, replace one H atom in the compound with Cl.