An Introduction to Chemical Formula
Understanding chemical symbology, valence, bonding, and frequent molecular structure is necessary for formulating all chemical formulas. Without initially learning how to write chemical formulas, it is impossible to construct chemical equations or answer the majority of chemical problems. A typical initial objective for a chemistry student is to understand how to develop formulas for a few basic inorganic compounds using a list of recommended common ions. The guidelines for creating these formulas aren't particularly complex. Utilizing the different ions to create basic formulas is an elementary activity after one is familiar with the different ions and their valences (the charge of the ion). So, this article explains chemical formulas with certain examples.
What is Meant by the Term Chemical Formula?
The term chemical formula refers to either of a number of expressions that describe the composition or form of chemical substances. Every constituent component in a chemical formula is identified with its chemical symbol, along with the relative number of atoms that make up each element.
Chemical formulas reveal the elements that make up a compound's molecules as well as the proportion in which their atoms mix to create those molecules. For instance, according to the molecular formula of water, H2O, a molecule of water, is made up of two hydrogen atoms and one oxygen atom.
Types of Chemical Formula
Commonly encountered forms include empirical, molecular, and structural ones.
Empirical formula: The proportion of the elements included in a chemical compound is represented by its empirical formula. Typically, empirical equations are developed by the examination of experimental results.
Molecular Formula: In a molecular formula, the component constituents' chemical symbols are accompanied by numerical subscripts. The atom counts of the constituent elements are indicated by the subscripts. The precise amount and kind of atoms in an individual molecule of a substance are specified by the molecular formula.
Molecular Formula = n × empirical formula
Structural Formula: Chemical bonds connecting the atoms of a molecule are located in structural formulae. A structural formula is made up of representations for the atoms joined by brief lines that stand in for chemical bonds. Single, double, and triple bonds are denoted by one, two, or three lines, accordingly.
Chemical formulas of sugar are used to explain the above-mentioned three types of chemical formulas.
The chemical formula of sugar is C12H22O11 which is also known as sucrose and provides the correct number of atoms in one sucrose molecule.
The empirical formula of sugar is the same as the molecular formula that is C12H22O11. Because it is known that 11 is a prime number and it does not contain any divisors. So, sugar holds the same empirical and molecular formula.
The structural formula of sucrose will reveal the bonds between each carbon, hydrogen, and oxygen atom in a sugar molecule.
Steps to Write Chemical Formula
When writing the chemical formula of a binary molecule, the following guidelines must be followed:
The valencies of the 2 radicals or elements that are available should be understood.
The compound's overall number of positive and negative valencies must equal zero in a chemical formula. Determining the least frequent multiple between the 2 valencies will help with this.
A positively-charged atom is referred to as a cation (Na+), while a negative-charged atom is referred to as an anion (Cl-).
The metal should generally come first in the formula if it is included.
Anions with a -1 negative charge typically end in -ide. Cl- - chloride, for instance.
Oxyanions, which are composed of oxygen and then another atom, typically contain the suffix -ate. For instance, PO43- (Phosphate)
Whenever a polyatomic anion contains an H- ion, the suffix bi- or hydrogen is utilized. For instance, hydrogen carbonate or HCO3 –Bicarbonate.
These steps are used to write the chemical formula of rust and baking soda.
The chemical formula of rust is Fe2O3 i.e Fe3+ and O2- and rust is also called ferric oxide or iron oxide.
The chemical formula of baking soda is NaHCO3. As per the rule, it is also called sodium bicarbonate or sodium hydrogen carbonate.
Key Features
When describing a substance in a chemical equation, its chemical formula is essential.
A compound's chemical structure is symbolically represented by its chemical formula. The proportions in which the component parts mix to create the composite are also represented by them.
Chemical formulas give information about a compound's chemical makeup.
Additionally, ions, free radicals, and additional chemical species can be represented using chemical formulas.
FAQs on Concept of Chemical Formula: A Detailed Summary
1. What are the three types of chemical formulas?
Empirical, Molecular, and structural formulas are the three main types of chemical formulas.
2. What is the molecular and empirical formula of glucose?
The molecular formula of glucose is C6H12O6, and the empirical formula of glucose is CH2O.
3. What are the basic rules for writing chemical formulas?
The basic rules for writing chemical formulas will be-
(i) Write the symbols that have a positive charge valency initially.
(ii) The valency of each atom should then be written above its symbol.
(iii) Divide the valency number by their largest common factor, ignoring the positive or negative radical, in the third step. The radical's valency should be switched.
(iv) Last but not least, take down the alternate valency number to the right of the radical.