State proper steps for writing chemical formulae from the knowledge of valency. Give an example in support of your answer.
State proper steps for writing chemical formulae from the knowledge of valency. Give an example in support of your answer.
Definition of chemical formulae
A chemical formula identifies each constituent element by its chemical symbol and indicates the proportionate number of atoms of each element. In empirical formulae, these proportions begin with a key element and then assign numbers of atoms of the other elements in the compound, by ratios to the key element.
Definition of valency
valency of an element is the measure of its combining capacity with other atoms when it forms chemical compounds or molecules.
Steps for writing chemical formula
To write the chemical formula for a compound it is best to use the S.V.S.D.F system.
- S - write down the symbols of both the elements involved.
- V - beneath each symbol, write its valency
- S - swap the valencies over.
- D - if the valencies can be simplified, divide them both by the smaller of the two numbers
For example,
- Potassium Chloride:
Name of the elementsSymbol Valency
Potassium Chlorine
Positive ions are written first
On interchanging the valencies
Formula =
- Calcium hydroxide
Name of the elements Symbol Valency Calcium Hydroxide
Positive ions are written first
On interchanging the valencies
Formula =
Definition of chemical formulae
A chemical formula identifies each constituent element by its chemical symbol and indicates the proportionate number of atoms of each element. In empirical formulae, these proportions begin with a key element and then assign numbers of atoms of the other elements in the compound, by ratios to the key element.
Definition of valency
valency of an element is the measure of its combining capacity with other atoms when it forms chemical compounds or molecules.
Steps for writing chemical formula
To write the chemical formula for a compound it is best to use the S.V.S.D.F system.
- S - write down the symbols of both the elements involved.
- V - beneath each symbol, write its valency
- S - swap the valencies over.
- D - if the valencies can be simplified, divide them both by the smaller of the two numbers
For example,
- Potassium Chloride:
Name of the elements | Symbol | Valency |
|---|---|---|
| Potassium | ||
| Chlorine |
Positive ions are written first
On interchanging the valencies
Formula =
- Calcium hydroxide
| Name of the elements | Symbol | Valency |
|---|---|---|
| Calcium | ||
| Hydroxide |
Positive ions are written first
On interchanging the valencies
Formula =
