State proper steps for writing chemical formulas from the knowledge of valency. give an example in support of your answer.
State proper steps for writing chemical formulas from the knowledge of valency. give an example in support of your answer.
Chemical Formulae of Compounds: The chemical formula of a compound is a representation of the composition of its molecule in which symbol represents, which elements are present and the subscript shows us how many atoms of each element are present in one molecule of a compound.
Writing the Formula of Molecular Compounds
If we know the valency of all the elements involved in a compound, then we can write the formula of that compound by balancing the valency of different elements.
The steps to be followed for writing the formula of molecular compounds are:
- Write the symbols of the elements constituting the compound.
- Then, below each symbol, write its corresponding valency.
- Finally, we exchange the valency of the combining atoms, i.e. with the first atom, we write the valency of the second atom, and with the second atom, we write the valency of the first atom. The valency is to be written as subscripts to the symbols.
- If the valency has any common factor, then the formula is divided by that common factor. This gives the required formula of the compound.
Example: Writing the formula of carbon dioxide.
The following steps are used to write the formula of carbon dioxide_
- Carbon dioxide is a compound composed of two elements, carbon, and oxygen. So, we first write their symbols C and O respectively.
- The valency of carbon is 4 and the valency of oxygen is 2. Now, these valencies are to be written under the corresponding symbols of elements.
- Now, the valency of carbon and oxygen are to be exchanged. So, the subscript corresponding to C is 2 and that corresponding to O is 4.
- Hence, the formula of the compound becomes
- But, valency 2 and 4 have a common factor 2. So, by dividing the whole formula by 2, we get the simplest formula
Thus, the formula of carbon dioxide is
Chemical Formulae of Compounds: The chemical formula of a compound is a representation of the composition of its molecule in which symbol represents, which elements are present and the subscript shows us how many atoms of each element are present in one molecule of a compound.
Writing the Formula of Molecular Compounds
If we know the valency of all the elements involved in a compound, then we can write the formula of that compound by balancing the valency of different elements.
The steps to be followed for writing the formula of molecular compounds are:
- Write the symbols of the elements constituting the compound.
- Then, below each symbol, write its corresponding valency.
- Finally, we exchange the valency of the combining atoms, i.e. with the first atom, we write the valency of the second atom, and with the second atom, we write the valency of the first atom. The valency is to be written as subscripts to the symbols.
- If the valency has any common factor, then the formula is divided by that common factor. This gives the required formula of the compound.
Example: Writing the formula of carbon dioxide.
The following steps are used to write the formula of carbon dioxide_
- Carbon dioxide is a compound composed of two elements, carbon, and oxygen. So, we first write their symbols C and O respectively.
- The valency of carbon is 4 and the valency of oxygen is 2. Now, these valencies are to be written under the corresponding symbols of elements.
- Now, the valency of carbon and oxygen are to be exchanged. So, the subscript corresponding to C is 2 and that corresponding to O is 4.
- Hence, the formula of the compound becomes
- But, valency 2 and 4 have a common factor 2. So, by dividing the whole formula by 2, we get the simplest formula
Thus, the formula of carbon dioxide is
