Question

Select correct statements(s):

• A. Cyan-amide ion $\left(C{N}_2^{2-}\right)$ is iso-electronic with $C{O}_2$ and has the same linear structure.
• B. $M{g}_2{C}_3$ reacts with water to form propane.
• C. $Ca{C}_2$ has $NaCl$ type of lattice.
• D. All the above are incorrect statements.

Answer 1

The correct option is A Cyan-amide ion $\left(C{N}_2^{2-}\right)$ is iso-electronic with $C{O}_2$ and has the same linear structure.

option A and C are correct statements.

Number of electrons in $C{N}_2^{2-}$ ion $=6+4+6=16$

Structure is $N^{-}=C=N^{-}$

Number of electrons in $C{O}_2=6+4+6=16$

Structure is $O=C=O$

Both have linear structure, hence $\left(C{N}_2^{2-}\right)$ ion is isoelectronic and isostructural with $C{O}_2$ molecule.

$M{g}_2{C}_3$ reacts with water to form propyne.

$M{g}_2{C}_3+H_{2}O\to Mg(OH{)}_2+C_3{H}_4$

$Ca{C}_2$ has $NaCl$ type of lattice.Calcium carbide has a distorted rock-salt structure at room temperature with the $C_2^{2-}$ units lying parallel.
Option A is correct.