For the self-ionisation (protonation) process liquid formic acid at `20^(@)`C.
`HCOOH+HCOOHto HCOOH_(2)^(+)+HCOO^(-)`
the equilibrium constant,
`K=([HCOOH_(2)^(+)][HCOO^(-)])/([HCOOH]^(2))=10^(-10)`
At `20^(@)`C, the density of liquid formic acid is 0.92 gm/mL.
How many formate ions `(HCOO^(-))` are present in each 5ml of liq.formic acid at `20^(@)` C? `(N_(A)=6xx10^(23))`

Options

A. `2xx10^(-4)`
B. `1.2xx10^(20)`
C. `6xx10^(17)`
D. `3xx10^(21)`

Answer

c