`75 mL` of `0.2 M HCl` is mixed with `25 mL` of `1 M HCl`. To this solution `300 mL` of distilled water is added. What is the pH of the resultant solution ?

Options

A. 1
B. 2
C. 4
D. 0.2

Answer

A

Explanation

`N = (V_(1)N_(1) + V_(2)N_(2))/("Total Number")`
`= (0.2 xx 75 + 1 xx 25)/(75 + 25 + 300) = 0.1`
`P^(H) = - log_(10)[H^(+)] = - log_(10)10^(-1)`
`:. P^(H) = 1`