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Homework Statement
Equal volumes of two solutions of hydrochloric acid are mixed. One solution has a pH 1 while the other pH 5. The pH of the solution obtained is?
A) Less than 1
B) Between 1 and 2
C) 3
D) Between 4 and 5
E) More than 5
Homework Equations
-log[H+] = pH
10-pH = [H+]
The Attempt at a Solution
let v = volume of solution 1 added
number of mol of H+ in solution with pH 1:
10-1 * v
number of mol of H+ in solution with pH 5:
10-5 * v
molarity of H+ in new solution
$$\frac {10^{-1} * v + 10^{-5} *v} {2v}$$
therefore $$pH = -log(\frac {10^{-1} + 10^{-5}}{2})$$
Hence pH = 1.300
Answer is B.
Is this correct?