Rank the following compounds in order of reactivity toward nitration with HNO3:. thiophene, benzene, 3-methylthiophene, and 2-methylfuran.

3-methylthiophene > thiophene > benzene > 2-methylfuran

Explanation:

Primarily, five membered heterocyclic aromatic rings undergo nitration at carbon-2. This is because, nitration at carbon-2 leads to the formation of three resonance structures while attack at carbon-3 yields only two resonance structures, hence it is less stabilized.

The presence of a methyl group which donates electrons promotes the stabilization of the cation formed in the nitration of 3-methylthiophene.

2-methylfuran is the least reactive towards nitration because the 2-position has been blocked by a methyl group.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.