Equal volumes of three acid solutions of pH 4, 5 and 6 are mixed in a vessel. What will be the `H^(+)` ion concentration in the mixture ?

Options

A. `3.7 xx 10^(-3)M`
B. `1.11 xx 10^(-3)M`
C. `1.11 xx 10^(-4)M`
D. `3.7 xx 10^(-5)M`

Answer

D

Explanation

`[H^(+)] = 10^(-3)M, [H^(+)] = 10^(-4)M, [H^(+)] = 10^(-5) M` for the given acids.
`M_("mix") V_("mix") = M_(1)V_(1) + M_(2)V_(2) + M_(3)V_(3) , M_("mix") xx 3 = 10^(-3) xx 1 + 10^(-4) xx 1 + 10^(-5) xx 1`
`M_("mix") = 10^(-5)([100 + 10 + 1])/(3) = (111 xx 10^(-5))/(3) = 37 xx 10^(-5)M = 3.7 xx 10^(-4)M`