pH/moles calcuation question (1 Viewer)

[.ben]

How do you do this question:

"Q. A paper mill produces waste water which contains 0.20M NaOH. What volume of HCl solution with a pH of 1 would be needed to bring 5000L to a pH of 7?"

THankyou!

 

[rama_v]

For the acid, [H+] = 10^-1 mol/L = 0.1M HCl

They are asking for complete neutralisation with no excess.
Moles of NaOH = n = c*V = 0.20*5000 = 1000 moles NaOH = 1000 moles OH-

So to neutralise this amount, we need V=1000/0.1 = 10000L HCL

 

[.ben]

oic now tks