Question

Rank the acidity of the following chemicals, from most acidic to least acidic: (think Anion stability!)

a. HF > CH3OH > CH3CO2H >CH3NH2

b. HF > CH3NH2 > CH3CO2H > CH3OH

c. CH3CO2H > CH3OH > CH3NH2 > HF

d. HF > CH3CO2H > CH3OH > CH3NH2

Answer 1

The correct option is d), HF>CH₃COOH>CH₃OH>CH₃NH₂

CH₃NH₂ is the only base, so we can leave that at the end, having the least acidic pH.

HF is a strong acid, meaning that it can easily donate that H⁺ ion.

Now the only dilemma is among acetic acid and methanol. We can say that the acetic acid has more capability of donating the H⁺ ion due to the oxygen's doble bond, which makes more attraction force on the oxygen and leaving more space for the H⁺ ion to liberate fromt he molecule. In the case of methanol, there is no strong force attracting the oxygen, which makes it more capable of staying attached to the hydrogen atom.