Question

Write the steps in deducing the chemical formulae of the following compounds.
a) Sodium sulphate

b) potassium nitrate

c) ferric phosphate

d) calcium oxide

e) aluminium hydroxide

Answer 1

a. Sodium sulphate:
Step 1: Write the symbols of the radicals
$Na$ $S{O}_4$
Step 2: Write the valency below the respective radical.
$Na$ $S{O}_4$
$1$ $2$
Step 3: Cross-multiply symbols of radicals with their respective valency.
Step 4: Write down the chemical formula of the compound.
$N{a}_{2}S{O}_4$
b. Potassium nitrate:
Step 1: Write the symbols of the radicals
$K$ $N{O}_3$
Step 2: Write the valency below the respective radical.
$K$ $N{O}_3$
$1$ $1$
Step 3: Cross-multiply symbols of radicals with their respective valency.
Step 4: Write down the chemical formula of the compound.
$KN{O}_3$
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.
$Al(OH{)}_3$