COMEDK20269 May 2026Morning ShiftChemistryd and f Block ElementsActual
K ₂ Cr ₂ O ₇ on heating with aqueous NaOH gives -------------------------
Options
- ACrO ₄²⁻
- BCr(OH) ₃
- CCrO ₃
- DCr(OH) ₂
Correct answer
A. CrO ₄²⁻
Step-by-step solution
When potassium dichromate ( K ₂ Cr ₂ O ₇ ) is treated with an alkali like aqueous NaOH, the orange dichromate ion is converted to the yellow chromate ion. The balanced chemical equation for the reaction is: Cr ₂ O ₇²⁻ + 2 OH ^- 2 CrO ₄²⁻ + H ₂ O Thus, the product formed is CrO ₄²⁻ . Answer: CrO ₄²⁻