Question

Write the formulae of the following compounds:
Sodium phosphate, Aluminum chloride, Calcium oxide, Potassium nitrate, Ammonium hydroxide

Answer 1

Hint: In order to write the formula of salt, first write the chemical symbol of the metal. Then write the chemical symbol of the anion. We do not need to show charge present on anions and cations in the chemical formula.

Complete step by step solution:
We are asked to write the formulae of the given inorganic compounds. We know that the inorganic compounds are made up of ions; cations and anions.
- In order to assign the chemical formula to salt, we first need to write the chemical symbol of metal and then we write the anions. We show the number of cations or anions present in the compound by writing a number in subscript. Let’s give a chemical formula to all the given compounds.
1) Sodium phosphate
The chemical symbol of sodium is Na and phosphate can be shown by $P{O_4}^{3 - }$. As there is -3 charge on phosphate, we require three sodium atoms to balance the charge. So, its chemical formula will be $N{a_3}P{O_4}$.
2) Aluminum Chloride
Aluminium has a chemical symbol of Al and chloride can be shown by $C{l^ - }$. Thus, we need three chlorine atoms in order to balance the charge as Al has charge of +3. So, its chemical formula will be $AlC{l_3}$.
3) Calcium Oxide
Calcium has a chemical symbol Ca and oxide can be shown as ${O^{2 - }}$. Thus, its chemical formula is CaO.
4) Potassium nitrate
The chemical symbol of potassium is K and nitrate can be shown by $N{O_3}^ - $. So, its chemical formula is $KN{O_3}$.
5) Ammonium hydroxide
Ammonium ions can be shown as $N{H_4}^ + $ and hydroxide ions can be shown as $O{H^ - }$. So, its chemical formula is $N{H_4}OH$.

Note: Do not get confused between nitrate and nitrite ions. Nitrate ions can be shown as $N{O_3}^ - $, here we can see that there are three oxygen atoms. In nitrite ion, there are two oxygen atoms and its formula is $N{O_2}^ - $.