Chemistry
posted by K .
How many mL of concentrated HCl(aq) (36% HCL by mass, d=1.18g/mL_ are required to produce 12.5 L of a solution with ph = 2.10?
First I started with finding out the concentration of [H30+] and for that I got 7.94 x 10^3 but I don't know how to continue.

I think the easiest way to solve this problem is to a)determine molarity of the HCl solution.
b) apply the dilution formula.
a) 1.18g/mL x 1000 mL = mass of 1 L HCl soln.
How much is HCl? That will be mass of 1L x 0.36 = ?? g HCl
How many moles is that. That will be grams HCl/molar mass HCl. That will be the molarity. Then L1 x M1 = 12.5L x 7.94E3. Then convert L to mL. 
Alright thanks so much.