In alkaline medium,the reduction of permanganate anion involves a gain of $........$ electrons.

Write the net ionic equation for the reaction of potassium dichromate$(VI)$,$K_{2}Cr_{2}O_{7}$ with sodium sulphite,$Na_{2}SO_{3}$ in an acidic solution to give chromium$(III)$ ion and the sulphate ion.

What is the oxidation state of chromium in the final product formed by the reaction between $KI$ and acidic $K_2Cr_2O_7$ solution?

In the reaction between hydrogen sulphide and acidified permanganate solution,which of the following occurs?

For a redox reaction,how many moles of electrons will one mole of $MnO_4^-$ accept in an acidic medium?

Which of the following solutions will turn violet when a drop of lime juice is added to it?