Verified answer

pH of 10^(-8) is 8 according to formula. but this indicates that the solution is basic in nature.on diluting an acidic solution very much, it becomes neutral, but cannot become basic.so its pH is

represented as 6.96 as it is almost neutral and some quantity of acid is present.similarly for basic solution also.pH=-log[H+]

for pH to be -ve concentration of H+ions should be 10^(+ve)

which bcannot exist.[H+] will be of the order 10^(-1 to -14).so pH

cant be negative.

pH is the negative log of the hydrogen ion concentration. If I'm straight on this the concentration is never zero but always less than 1 so the pH will never be a negative number.

HCl dissassociates into hydrogen ions and increases the hydrogen ion concentration. Since ph is negative log of the concentration the pH goes down.

NaOH breaks releases OH ions into the solution which will combine with any free hydrogen ions to form water so the hydrogen ion concentration is reduced, and the ph number gets larger.

That's about it.