Q. 6.43 - An Introduction to General, Organic, and Biological Chemistry

Question

Write the formula for the polyatomic ion and name each of the following compounds:

a. ${\mathrm{Na}}_2{\mathrm{CO}}_3$    b. ${\left({\mathrm{NH}}_4\right)}_2\mathrm{S}$

b. $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$    d. $\mathrm{Sn}{\left({\mathrm{NO}}_2\right)}_2$

Step-by-Step Solution

Answer

a.  The name of the compound ${\mathrm{Na}}_2{\mathrm{CO}}_3$ is sodium carbonate and ${\mathrm{CO}}_3^{2-}$ is polyatomic ion.

b.  The name of the compound $\left({\mathrm{NH}}_4\right)\mathrm{S}$ is ammonium sulfide and  ${\mathrm{NH}}_4^{+}$ is polyatomic ion.

c.  The name of the compound $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$ is calcium hydroxide and ${\mathrm{OH}}^{-}$ is polyatomic ion.

d.  The name of the compound $\mathrm{Sn}{\left({\mathrm{NO}}_2\right)}_2$ is tin(II) nitrite and ${\mathrm{NO}}_2^{-}$ is polyatomic ion.

Part (a) Step 1 : Given information

We have to write the formula for the polyatomic ion and name of ${\mathrm{Na}}_2{\mathrm{CO}}_3$ compound.

Part (a) Step 2 : Simplification

We know that ${\mathrm{Na}}_2{\mathrm{CO}}_3$ can be written as ${\mathrm{Na}}^{+}$ and ${\mathrm{CO}}_3^{2-}$ in ionic form,

So, its polyatomic ion is ${\mathrm{CO}}_3^{2-}$ and its name is Sodium carbonate.

Part (b) Step 1 : Given information

We have to write the formula for the polyatomic ion and name of ${\left({\mathrm{NH}}_4\right)}_2\mathrm{S}$ compound.

Part (b) Step 2 : Simplification

We know that ${\left({\mathrm{NH}}_4\right)}_2\mathrm{S}$ can be written as ${\mathrm{NH}}_4^{+}$ and ${\mathrm{S}}^{2-}$ in ionic form,

So, its polyatomic ion is ${\mathrm{NH}}_4^{+}$ and its name is ammonium sulfide.

Part (c) Step 1 : Given information

We have to write the formula for the polyatomic ion and name of $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$ compound.

Part (c) Step 2 : Simplification

We know that $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$ can be written as ${\mathrm{Ca}}^{2+}$ and ${\mathrm{OH}}^{-}$ in ionic form,

So, its polyatomic ion is ${\mathrm{OH}}^{-}$  and its name is calcium hydroxide.

Part (d) Step 1 : Given information

We have to write the formula for the polyatomic ion and name of $\mathrm{Sn}{\left({\mathrm{NO}}_2\right)}_2$ compound.

Part (d) Step 2 : Simplification

We know that $\mathrm{Sn}{\left({\mathrm{NO}}_2\right)}_2$ can be written as ${\mathrm{Sn}}^{2+}$ and ${\mathrm{NO}}_2^{-}$ in ionic form,

So, its polyatomic ion is ${\mathrm{NO}}_2^{-}$  and its name is tin(II) nitrite.