Which of the following statement is wrong?

Options

A. An acidified solution of `K_(2)Cr_(2)O_(7)` liberates iodine from iodides.
B. In acidic solution dichromate ions are converted to chromate ions.
C. Ammonium dichromate on heating undergo exothermic decomposition to give `Cr_(2)O_(3)`
D. Potassium dichromate is u sed as a titrant for `Fe^(2+)`.

Answer

B

Explanation

(1) `Cr_(2)O_(7)^(2-)+14H^(+)+6I^(-)to2Cr^(3+)+3I_(2)+7H_(2)O`
2. In acidic solution, actually chromate is converted to dichromate to dichromate.
`2CrO_(4)^(2-)+2H^(+)toCr_(2)O_(7)^(2-)+H_(2)O`
3. `(NH_(4))_(2)Cr_(2)O_(7)overset(Delta)toN_(2)+4H_(2)O+Cr_(2)O_(3)`.
4. `6Fe^(2+)+Cr_(2)O_(7)^(2-)+14H^(+)to6Fe^(3+)+2Cr^(3+)+7H_(2)O`