Question 2 :
Which of the following acts both as oxidising as well as reducing agent?

Question 3 :
Out of the halogens, which one is the most powerful oxidizing agent?

Question 4 :
How many moles of electrons are involved in the reduction of one mole of $MnO^-_4$ ion in alkaline medium to $MnO^-_3$?

Question 5 :
Change of orange color of chromium(VI) to green color of chromium(III) indicates presence of a:

Question 7 :
Three cations $A, B, C$ are allowed to react with ammonium hydroxide solution. $A$ and $B$ produce a dirty green precipitate and a reddish brown precipitate respectively, both of which do not dissolve on further addition of ${NH}_{4}OH$. $C$ gives pale blue colour precipitate with less amount of ammonium hydroxide and on further addition of ${NH}_{4}OH$, precipitate becomes soluble and deep blue colour solution is formed:

Question 11 :
Which one of the following reactions does not involve either oxidation or reduction

Question 12 :
Iron (III) oxide on heating with carbon monoxide gas form solid iron and liberates carbon dioxide gas. This is a:<br/>