Question

A chloride of alkaline earth metal dissolves appreciably in cold water when placed on a platinum wire in Bunsen flame, no distinctive color is noticed. The cation of chloride is:

• A. $M{g}^{2+}$
• B. $B{a}^{2+}$
• C. $S{r}^{2+}$
• D. $C{a}^{2+}$

Answer 1

The correct option is A $M{g}^{2+}$

As we know, out of all the metals of group 2, $M{g}^{2+}$ and $B{e}^{2+}$ do not give flame test. $M{g}^{2+}$ does not impart color to the Bunsen flame because of its its small size, the electrons of $M{g}^{2+}$ are tightly attached to the nucleus. Hence, electrons need large amount of energy for excitation. Therefore, it does not impart color to the flame.