The pH of a solution obtained by mixing 100mL of `0.1M HCI` and `9.9mL` of `0.1M` NaOH` is:

Options

A. `3.0409`
B. `3.4049`
C. `2.0409`
D. None of these

Answer

A

Explanation

`{:(,HCI+,NaOHrarr,NaCI+,H_(2)O),("Meq. before reaction", 100xx0.1,9.9xx1, ,),(, =10,=9.9,0,0),("Meq. after reaction", 0.1,0,9.9,9.9):}`
`:. [H^(+)]"left from" HCI =(0.1)/(109.9)`
`=9.099xx10^(-4)M`
`pH= -log H^(+)= - log 9.099xx10^(-4)`
`pH= 3.0409`