Question

Aqueous solutions of `Na_(2)C_(2)O_(4)` and `CaCI_(2)` are mixed and precipitate of `CaC_(2)O_(4)` formed is filered and dried. `250 mL` of the saturated solution of `CaC_(2)O_(4)` required `6.0 mL` of `0.001M KMnO_(4)` solution in acidic medium for complete titration.
Number of mol of `KMnO_(4)` required is this titration and number of mol of `C_(2)O_(4)^(2-)` ion present in the given saturated solution fo `CaC_(2)O_(4)` respectively are
A. `6xx10^(-6), 6 xx 10^(-6)`
B. `6 xx 10^(-6),1.5 xx 10^(-5)`
C. `1.5 xx 10^(-5),6 xx 10^(-6)`
D. `6xx10^(-6),3xx10^(-6)`

Answer 1

Correct Answer - B
i. Moles of `KMnO_(4)` used `= (6xx0.001)/(1000) = 6 xx 10^(-6)`
`(2MnO_(4)^(Theta))/(2mol) + (5C_(2)O_(4)^(2-))/(5mol) + 16H^(o+) rarr 2Mn^(2+) + 10CO_(2) + 8H_(2)O`.
ii. mol of `C_(2)O_(4)^(2-) = (5)/(2) mol of MnO_(4)^(Theta)`
`= (5)/(2) xx 6 xx 10^(-6) = 1.5 xx 10^(-5)`