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.$\mathrm{Sn}{\left({\mathrm{NO}}_2\right)}_2$

Short 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.

Step-by-step solution

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.