Question

What is the PH of 2N HCL solution​

Answer 1

The solution prepared by adding one drop of 2 M HCl to 100 mL of water would therefore have a pH of 3.

Answer 2

HCl is HYDROCHLORIC ACID and results a VERY STRONG ACID because It takes part to ionic dissociation in aqueous solutions TO GIVE HYDRONIUM IONs (e.g. H3O+)

HCl(aq) + H2O(aq) ---> H3O+(aq) + Cl-(aq)

Now, We may assume that

|HCl| = |H3O+| = 2 M

Here, We need to assume that all the acid will dissociate into its ionic state!

So, Concentration of H+ ions = 2.0 M

pH=−log[H+]

Log (2) = 0.301

pH = - log = - 0.301 (VERY highly acidic)

Wait! Now, you may think that pH scale is defined from 0 to 14 only. How came negative pH?

Let me correct you on fact. Negative pH or pH greater than 14 is also possible.

• The range of pH in water is 0 to 14 (to be more precise, it is -1.7 to 15.7). pH actually indicates the ability of the acid to form H3O+ in water, which can then donate a proton. So, at pH = 0, all water is basically protonated, your acid cannot release it's H+, and what you get is pH = 0 and no lower.
• Acids do not have pH, they have pKa. An acid can have a negative pKa.
• A solution has a pH, and pH can be negative. In practice, any acid that yields a concentration of hydrogen ions with a molarity greater than 1 will be calculated to have a negative pH.

Thanks. Best wishes for your preparation. Keep asking! :)

Hope this'll help you.