Correct statements(s) is `//` are

Options

A. an acidified solution of `K_(2)Cr_(20O_(7)` liberates iodine from KI
B. `K_(2)Cr_(2)O_(7)` is used as a standard solution for estimation of `Fe^(2+)` ions
C. in acidic medium , `M=N//6` for `K_(2)Cr_(2)O_(7)`
D. `(NH_(4))_(2)Cr_(2)O_(7)` on heating decomposes to yield `Cr_(2)O_(3)` through an endothermic reaction

Answer

A,B,C

Explanation

`(A) 2MnO_(4)^(-)+2NH_(3)rarr2MnO_(2)+N_(2)+2OH^(-)+2H_(2)O`