Question

Describe what happens on the molecular level when acetic acid dissolves in water.

Short answer

You need to describe what happens on the molecular level when acetic acid dissolves in water.

Step-by-step solution

Solution of the problem

At the molecular level, acetic acid dissolves in water and produces H₃O⁺ and CH₃COO^- ions which again associates and forms CH₃COOH and H₂O. The equilibrium is reached after 2% ionization of CH₃COOH.

Explanation of the solution

Acetic acid dissolves in water and produces H₃O⁺ and CH₃COO^- ions which again associate and forms CH₃COOH and H₂O.

Hence, the equilibrium can be written as

$C{H}_{3}COOH\left(aq\right)+H_{3}O\rightleftharpoons H_3{O}^{+}\left(aq\right)+C{H}_{3}CO{O}^{-}\left(aq\right)$

Explanation of the equilibrium

Weak acid CH₃COOH dissolves in water and forms H₃O⁺ and CH₃COO^- ions. As it is a weak acid, so less amount of H₃O⁺ and CH₃COO^- ions are produced. When there are enough concentration of H₃O⁺ and CH₃COO^- ions are present in the reaction mixture, and then they re-associate and forms CH₃COOH and H₂O.

After some time, the rate of forward and backward reaction becomes same and the equilibrium reached.

Conclusion

At the molecular level, acetic acid dissolves in water and produces H₃O⁺ and CH₃COO^- ions which again associates and forms CH₃COOH and H₂O. The equilibrium is reached after 2% ionization of CH₃COOH.