Question

$C{r}_2{O}_7^{2-}\underset{pH=Y}{\overset{pH=X}{\rightleftharpoons }}Cr{O}_4^{2-}$
The value of $Y$ and $X$ respectively are

• A. 3, 8
• B. 8, 4
• C. 8, 10
• D. 10, 2

Answer 1

Answer: (A)

The chromate ion (yellow) is the predominant species in alkaline solutions, dichromate (orange) predominant in acidic solutions. When an alkali is added to an orange red solution of dichromate, an yellow solution is obtained due to the formation of chromate ions.