Question

the ph of 10^-9m solution of hcl in water is ​

Answer 1

Neutral water always contains 1 X 10–7 mol of H+ ion in it. 1 X 10–9M (HCl ) acid means it will contain (10–7 +10–9) H+ ions in it.

H+ ion concentration =10–7 +10–9

=1 X10–7 +0.01 X10-7

=1.01 X 10–7

So the pH of 10–9M acid =-log(1.01 X 10–7)

pH =6.99567