# CH_3 OH and HCI both dissolve in water, but the dissolved HCI conducts electricity, while the dissolved CH_3 OH doesn't. Why?

Jun 6, 2018

The Hydrochloric acid dissolves as ions which conduct electricity being charged particles.
The ethanal or ethyl alcohol dissolves as a molecule which does not conduct electricity lacking any charged particles.

#### Explanation:

The $H C l$ is an ionic compound which is separated by the polar nature of water into H+ and Cl- ions. These charged particles conduct electricity.

ethyl alcohol is a covalent compound which is separated by the polar nature of water into separate molecules. These separate molecules are not charged and so do not conduct electricity.

Jun 6, 2018

Actually, it does, it just conducts electricity to a very very small extent......

#### Explanation:

Be careful about "black and white" statements like "this doesn't conduct electricity". In reality, a solution of methanol and water does conduct electricity, just to a MUCH lower extent than a solution of HCl in water.

HCl dissociates into ${H}_{3} {O}^{+}$ and $C {l}^{-}$ ions in aqueous solutions, and it fully dissociates (which is why hydrochloric acid is a strong acid). Methanol in water also dissociates into ions,

2CH3OH = CH_3OH_2^++ −CH_3O^-

The self-ionisation constant of methanol will be very low, it will be only marginally different to that of water (which is about 10^(−14).

So the ions will be present and will conduct electricity in a methanol/water solution, it just does it to a very very small extent. But to say that they "do not conduct" electricity implies a conductivity of zero. It will not be zero, but it will be EXTREMELY small.