Question

In which of the following sets all the compounds are ionic?
a) $\text{BC}{{\text{l}}_{\text{3}}}\text{, BeC}{{\text{l}}_{\text{2}}}\text{, MgO}$
b) $\text{LiF , MgC}{{\text{l}}_{\text{2}}}\text{, N}{{\text{a}}_{\text{2}}}\text{O}$
c) $\text{N}{{\text{H}}_{\text{4}}}\text{Cl , B}{{\text{F}}_{\text{3}}}\text{, C}{{\text{O}}_{\text{2}}}$
d) $\text{AgCl , AlC}{{\text{l}}_{\text{3}}}\text{, PC}{{\text{l}}_{\text{5}}}$

Answer 1

Hint:
For two elements to make an ionic bond there should be enough electronegativity difference that one of them readily gives an electron and the other one readily accepts it, so one should be metal and other should be a non metal.

Complete step by step solution:
a) $\text{BC}{{\text{l}}_{\text{3}}}\text{, BeC}{{\text{l}}_{\text{2}}}\text{, MgO}$:
$\text{BC}{{\text{l}}_{\text{3}}}$ is covalent as both $\text{B}$ and are non metals.
$\text{BeC}{{\text{l}}_{\text{2}}}$is covalent as both $\text{Be}$ and $\text{Cl}$ are non metals.
$\text{MgO}$ is ionic as $\text{Mg}$is metal and $\text{O}$ is a non metal.
b) $\text{LiF , MgC}{{\text{l}}_{\text{2}}}\text{, N}{{\text{a}}_{\text{2}}}\text{O}$:
$\text{LiF}$ is ionic as $\text{Li}$ is metal and $\text{F}$ is non-metal.
$\text{MgC}{{\text{l}}_{\text{2}}}$is ionic as $\text{Mg}$ is metal and $\text{Cl}$ is a non metal.
$\text{N}{{\text{a}}_{\text{2}}}\text{O}$is ionic as $\text{N}{{\text{a}}_{\text{2}}}$Na is metal and $\text{O}$ is a non metal.
c) $\text{N}{{\text{H}}_{\text{4}}}\text{Cl , B}{{\text{F}}_{\text{3}}}\text{, C}{{\text{O}}_{\text{2}}}$:
$\text{N}{{\text{H}}_{\text{4}}}\text{Cl}$ is ionic as $\text{N}{{\text{H}}_{\text{4}}}$NH4 is metal and $\text{Cl}$ is a non metal.
$\text{B}{{\text{F}}_{\text{3}}}$ is covalent as both $\text{B}$ and $\text{F}$ are non metals.
$\text{C}{{\text{O}}_{\text{2}}}$ is covalent as both $\text{C}$and $\text{O}$ are non metals.
d) $\text{AgCl , AlC}{{\text{l}}_{\text{3}}}\text{, PC}{{\text{l}}_{\text{5}}}$:
$\text{AgCl}$ is ionic as $\text{Ag}$ is metal and $\text{Cl}$ is non-metal.
$\text{AlC}{{\text{l}}_{\text{3}}}$ is ionic as $Al$ is metal and $\text{Cl}$is a non metal.
$\text{PC}{{\text{l}}_{\text{5}}}$is covalent as both P and $\text{Cl}$are non metals.
Hence, we can conclude from above information that all $\text{LiF, MgC}{{\text{l}}_{\text{2}}}\text{, N}{{\text{a}}_{\text{2}}}\text{O}$ are ionic.

Therefore, option B is correct.

Note: An ionic compound is a chemical compound which is composed of ions held together by electrostatic forces. An ionic compound is neutral overall, but consists of positively charged ions called cations and negatively charged ions called anions