Question

If the chemical formula of metal carbonate is ${{M}_{2}}C{{O}_{3}}$ , then choose the correct option from the following
1. The chemical formula of metal iodide will be $MI$
2. The chemical formula of metal nitride will be ${{M}_{3}}{N}_{2}$
3. The chemical formula of metal phosphate will be ${{M}_{3}}P{{O}_{4}}$
(A) $1$ and $2$ only
(B) $2$ and $3$ only
(C) $1$ and $3$ only
(D) Only $2$

Answer 1

Hint : The chemical formula of metal carbonate is ${{M}_{2}}C{{O}_{3}}$ . The valency of Metal in ${{M}_{2}}C{{O}_{3}}$ is $+1$ . By identifying the valency of each element, crossing over the valency with the elements, we can calculate the chemical formula.

Complete Step By Step Answer:
For Metal Iodide, the valency of M is $+1$ and valency of Iodide is $-1$
By crossing over, we will get MI
crossing over: M( $-1$ ) I( $+1$ ) $M(-3),P{{O}_{4}}(+1)$ $=MI$
The chemical formula of Metal iodide is MI
Therefore, the first statement: The chemical formula of metal iodide will be $MI$ is correct
For Metal nitride, the valency of M is $+1$ and Nitride is $-3$
By crossing over, we will get ${{M}_{3}}N$
crossing over: $M(-3),$ $N(+1)$ $={{M}_{3}}N$
The chemical formula of Metal nitride is ${{M}_{3}}N$
Therefore, the second statement : The chemical formula of metal nitride will be $M_3N_2$ is incorrect
For Metal Phosphate, the valency of M is $+1$ and Phosphate is $-3$
By crossing over, we will get ${{M}_{3}}P{{O}_{4}}$
crossing over: $M(-3),P{{O}_{4}}(+1)$
The chemical formula of Metal phosphate is ${{M}_{3}}P{{O}_{4}}$
Therefore, the last statement: The chemical formula of metal phosphate will be ${{M}_{3}}P{{O}_{4}}$ is correct
Thereby the correct option is C
The option a) $1$ and $2$ only is incorrect
The option b) $2$ and $3$ only is incorrect
The option d) Only $2$ is incorrect
Metal carbonate belongs to a type of base which has the ability to produce the required salt , water and carbon dioxide when they are forced to react with acid.
The option (C) $1$ and $3$ only is correct.

Note :
The chemical formula of Metal iodide is MI. The chemical formula of Metal nitride is ${{M}_{3}}N$ . The chemical formula of Metal phosphate is ${{M}_{3}}P{{O}_{4}}$ . .In these types of questions eliminate the incorrect option to make the question simpler.