Question

CH3CN major species present when dissolved in water

Answer 1

The major species present when CH3CN is dissolved in water are CH3+ and CN-. It doesn't completely dissociate in water since it is not a strong acid or strong base. Only a strong acid or base will dissociate completely in water. For example HCl dissociates into H+ and Cl-, and NaOH dissociates into Na+ and OH-.

Answer 2

Answer: CH₃CN and H₂O.

Explanation:

1) The spieces present in a solution may be either the molecules, in case of covalent compounds, or ions, in case of ionic compounds that dissociate (ionize).

2) Both, CH₃CN and H₂O are covalent (polar covalent) substances, so they do not ionize and the spieces in the solution are the molecules per se.

3) In solution, the molecules of H₂O will solvate the molecules of CH₃CN, meaning that H₂O molecules are able to separate the molecules of CH₃N from each other, and so every molecule of CH₃CN will end surrounded by many molecules of H₂O.

This happens because the interaction between the polar molecules of the two different compounds is strong enough to overcome the intermolecular forces between the molecules of the same compound.