Acidified potassium dichromate reacts with potassium iodide and oxidises it to$${I_2}.$$ What is the oxidation state of chromium in the products of the reaction?
A.
+4
B.
+6
C.
+3
D.
+2
Answer :
+3
Solution :
During the reaction $${K_2}C{r_2}{O_7}$$ is converted to $$C{r_2}{\left( {S{O_4}} \right)_3}$$
$${K_2}C{r_2}{O_7} + 7{H_2}S{O_4} + 6KI \to $$ $$4{K_2}S{O_4} + C{r_2}{\left( {S{O_4}} \right)_3} + 7{H_2}O + 3{I_2}$$
$${\text{In}}\,\,{\text{C}}{{\text{r}}_2}{\left( {S{O_4}} \right)_3},O.S.\,\,{\text{of}}\,\,Cr\,\,{\text{is}}\, + 3.$$
Releted MCQ Question on Inorganic Chemistry >> D and F Block Elements
Releted Question 1
When same amount of zinc is treated separately with excess of sulphuric acid and excess of sodium hydroxide, the ratio of volume of hydrogen evolved is