1. A Review of General Chemistry

How many constitutional isomers exist for a molecule with the molecular formula $C_2{H}_4{\mathrm{Cl}}_2$?

Which of the following pairs are constitutional isomers of $C_2{H}_6{O}_2$?

Which of the following best describes constitutional isomers?

Which of the following pairs of compounds are constitutional isomers?

Which of the following pairs of compounds are constitutional isomers?

Which of the following pairs of hydrocarbons are constitutional isomers of each other?

Which of the following pairs of compounds are constitutional isomers?

Which of the following is not a type of constitutional isomer?

Which of the following pairs are constitutional isomers of $C_2{H}_3{\mathrm{Cl}}_3$?