Question

Write the steps in deducing the chemical formulae of the following compounds.

Sodium sulphate, potassium nitrate, ferric phosphate, calcium oxide, aluminium hydroxide

Answer 1

a.Sodium sulphate :
Step 1 : Write the symbols of the radicals.
Na SO₄
Step 2 : Write the valency below the respective radical.
Na SO₄
1 2
Step 3 : Cross-multiply symbols of radicals with their respective valency.


Step 4 : Write down the chemical formula of the compound.

Na₂SO₄


b. Potassium nitrate :
Step 1 : Write the symbols of the radicals
K NO₃

Step 2 : Write the valency below the respective radical.
K NO₃
1 1
Step 3 : Cross-multiply symbols of radicals with their respective valency.

Step 4 : Write down the chemical formula of the compound.

KNO₃


c. Ferric phosphate :
Step 1 : Write the symbols of the radicals
Fe PO4

Step 2 : Write the valency below the respective radical.
Fe PO4
3 3
Step 3 : Cross-multiply symbols of radicals with their respective valency.

Step 4 : Write down the chemical formula of the compound.

FePO4


d. Calcium oxide :
Step 1 : Write the symbols of the radicals
Ca O

Step 2 : Write the valency below the respective radical.
Ca O
2 2

Step 3 : Cross-multiply symbols of radicals with their respective valency.

Step 4 : Write down the chemical formula of the compound.

CaO


e. Aluminium hydroxide :
Step 1 : Write the symbols of the radicals
Al OH

Step 2 : Write the valency below the respective radical.
Al OH
3 1

Step 3 : Cross-multiply symbols of radicals with their respective valency.

Step 4 : Write down the chemical formula of the compound.

Al(OH)₃