The amount of caustic and HCl to increase and decrease the pH of water by 2 ?

[RuwanR]

I need to figure out what is the amount of caustic we need to increase the pH of 1L water from 7 to 9 and the amount of HCL to bring down the pH of 1 L water from 7 to 5.
Here we find caustic granules of 99 % concentration and 32 % HCL .
Can you please work that out for me? I’d be grateful if you could show me the method how to find that.
Thank you very much.

 

[bimr]

The first step is to obtain a water analysis to determine the alkalinity.

 

[moltenmetal]

...and until you know the alkalinity, you can't know the answer within even a couple orders of magnitude- unless it's distilled or deionized water, i.e. you know that the alkalinity is zero.