It is alkaline.
The alkalinity of the solution is due to the capacity of the solution to neutralize acid. This happens when hydroxide content will increase. Apparently in this process we will try to look if any hydroxide will form in the electrolysis of concentrated NaCl solution.
During the electrolysis of NaCl solution, the following phenomena happens:
Chlorine gas forms at the anode
Hydrogen gas forms at the cathode
a solution of sodium hydroxide is forms
amount of sodium Chloride decreases
The formation of Sodium Hydroxide will make the solution alkaline.
Hope this helps :)
My answer is that the solution will be alkaline (NaOH will be formed) because the chlorine will be given off at the anode and hydrogen at the cathode..