Chemistry - Complete d-block Question with Solution | TestHub

$$4K_{2}C{r}_2{O}_7\stackrel{\Delta }{\to }4K_{2}Cr{O}_4(Yello{w}^{\prime }{X}^{\prime })+2C{r}_2{O}_3(Gree{n}^{\prime }{Y}^{\prime })+3O_2\uparrow$$

Statement A is incorrect because 'Y' is chromium(III) oxide ($C{r}_2{O}_3$), not $Cr{O}_3$.

Statement B is correct as yellow chromate (X) turns into orange dichromate ($C{r}_2{O}_7^{2-}$) in acidic $H_{2}S{O}_4$.

Statement C is correct because reacting X with $H_2{O}_2$ in acid forms deep-blue chromium peroxide ($Cr{O}_5$).

Statement D is correct because heating ammonium dichromate yields nitrogen gas, water, and green $C{r}_2{O}_3$ ('Y').