Give a reason for each of the following: (a) The purple colour of disappears in the presence of…

Give a reason for each of the following: (a) The purple colour of $\text{KMnO}_4$ disappears in the presence of acidified solution of oxalic acid. (b) Some transition metals and their compounds get attracted towards the magnetic field. (c) Why are $\text{Mn}^{2+}$ compounds more stable than $\text{Fe}^{2+}$ towards oxidation to the +3 state? (atomic no. of $\text{Mn} = 25$ and $\text{Fe} = 26$)