An indicator 'X' is used for studying the effect of variation in concentration of iodide on the rate of reaction of iodide ion with $$\mathrm{H_2O_2}$$ at room temp. The indicator 'X' forms blue coloured complex with compound 'A' present in the solution. The indicator 'X' and compound 'A' respectively are

Which one amongst the following are good oxidizing agents?

A. Sm$$^{2+}$$

B. Ce$$^{2+}$$

C. Ce$$^{4+}$$

D. Tb$$^{4+}$$

Choose the most appropriate answer from the options given below :

An ammoniacal metal salt solution gives a brilliant red precipitate on addition of dimethylglyoxime. The metal ion is :

In liquation process used for tin (Sn), the metal