Chemical Formula
Chemical formula is a way to describe chemical ratios of atoms that make up a specific chemical compound or molecule in chemistry. Chemical element symbols, numbers, and sometimes other symbols, such as parentheses, dashes, brackets, commas, plus (+), and minus (-) signs, are used to represent the chemical elements, atoms, or ions. A chemical substance that contains atoms from at least two different elements is referred to be a chemical compound. Chemical compounds and molecules both contain many atoms, but unlike chemical compounds, a molecule can just be made up of atoms from the same element.
In this article, we have covered, Definition of Chemical Formula, Importance of Chemical Formula, Types of Chemical Formulae, and others in detail.
Table of Content
- What is Chemical Formula?
- Importance of Chemical Formula
- Types of Chemical Formulae
- How to Write Chemical Formula?
- Chemical Formula of Some Common Compounds
- Chemical Formula Table
What is Chemical Formula?
A chemical formula is a representation of a substance’s molecular composition in terms of the symbols representing the components that make up the molecule. A molecular formula is another name for a chemical formula.
An element’s or a compound’s chemical formula can be used. A chemical formula is a technique of presenting information on the chemical proportions of atoms that make up a chemical compound or molecule using chemical element symbols, numbers, and other symbols like parentheses, dashes, brackets, and commas.
Importance of Chemical Formula
The importance of Chemical Formulas can be understood as,
- Compound’s name is represented by a formula.
- Names of all the elements in the molecule are given in formulae.
- Number of atoms of each element contained in a molecule is given by formulae.
- One molecule of a compound is represented by a formula.
- Formulae denote a definite mass of a substance.
Types of Chemical Formulae
There are different types of chemical formulae based on the composition of chemical compounds:
- Molecular Formula
- Empirical formula
- Structural formula
Molecular Formula
Amount of elements in a substance can be determined from its molecular formula. The periodic table’s symbols are used to represent the elements in molecular formulae, and a subscript is used to indicate how many atoms of each element are present in the molecule.
Example:
- Molecular formula of Urea is CH4N2O which gives exact number of constituent atoms (i.e Carbon, Hydrogen and Nitrogen in one Urea molecule
- Molecular formula of Acetic Acid is CH3COOH
- Molecular formula of Glucose is C6H12O6
Empirical Formula
Ratio of the elements present in a chemical compound is represented by its empirical formula. Usually, empirical formulas are developed by the evaluation of experimental data.
Example:
- Empirical formula of Urea is CH4N2O
- Empirical formula of Acetic Acid is CH2O
- Empirical formula of Glucose is CH2O
Structural Formula
Structural formula of a chemical compound gives understanding of the arrangement of the atoms in the molecule.
Example:
Structural formula of Urea is shown below,
Structural formula of Acetic Acid is shown below,
How to Write Chemical Formula?
A binary compound is composed of two different elements only. Formulae of binary compounds can be written with the help of valency of elements since both types of atoms forming the compound must lose, gain or share the same number of electrons.
Points to be considered to write the molecular formula
- Determine the valency of the elements present in the compound.
- Write the chemical formula such that the sums of the valency of the two elements are equal. Do this by determining the lowest common multiple of the two valency.
- Always place metals first in the formula.
Chemical Formula of Rust
Elements present in Rust are Iron and Oxygen. Then,
Symbol |
Iron, Fe (26) |
Oxygen, O (8) |
---|---|---|
Valency |
3 |
2 |
Lowest common multiple of valency is 6. Therefore,
Fe = 2 × 3 = 6
O = 3 × 2 = 6
This implies that the chemical formula is Fe2O3
Chemical Formula of Aluminium Oxide
The elements present in Aluminium Oxide are Aluminium and Oxygen. Then,
Symbol |
Aluminium, Al (13) |
Oxygen, O (8) |
---|---|---|
Valency |
3 |
2 |
The lowest common multiple of valency is 6. Therefore,
Al = 2 × 3 = 6
O = 3 × 2 = 6
This implies that the chemical formula is Al2O3
Chemical Formula of Methane
Elements present in Methane are Carbon and Hydrogen. Then,
Symbol | Carbon, C (6) | Hydrogen, H (1) |
---|---|---|
Valency |
4 |
1 |
Lowest common multiple of valency is 4. Therefore,
C = 1 × 4
H = 4 × 1
This implies that the chemical formula is CH4
Chemical Formula of Sodium Chloride
Elements present in Sodium Chloride are Carbon and Hydrogen. Then,
Symbol | Sodium, Na (11) | Chlorine, Cl (17) |
---|---|---|
Valency |
1 |
1 |
Lowest common multiple of valency is 4. Therefore,
Na = 1
Cl = 1
This implies that the chemical formula is CH4
Chemical Formula of Calcium Oxide
Elements present in Calcium Oxide are Calcium and Oxygen. Then,
Symbol | Calcium, Ca (20) | Oxygen, O (8) |
---|---|---|
Valency |
2 |
2 |
Lowest common multiple of valency is 2. Therefore.
Ca = 1 × 2
O = 1 × 2
This implies that the chemical formula is CaO.
Chemical Formula of Some Common Compounds
- Chemical formula of Plaster of Paris: CaSO4.1/2H2O
- Chemical formula of Bleaching Powder: CaOCl2
- Chemical formula of Alcohol: C2H5OH (Ethyl Alcohol)
Chemical Formula Table
The table given below gives the chemical symbol and molecular weight of some common compounds
Compound Name |
Chemical Symbol |
Molecular Weight (g/mol) |
---|---|---|
Acetic acid | CH3COOH | 60.052 |
Hydrochloric acid | HCl | 36.458 |
Sulfuric acid | H2SO4 | 98.072 |
Ammonia | NH3 | 17.031 |
Nitric acid | HNO3 | 63.012 |
Phosphoric acid | H3PO4 | 97.994 |
Sodium phosphate | Na3PO4 | 119.976 |
Calcium carbonate | CaCO3 | 100.086 |
Ammonium sulfate | (NH4)2SO4 | 132.134 |
Carbonic acid | H2CO3 | 62.024 |
Sodium bicarbonate | NaHCO3 | 84.0066 |
Sodium hydroxide | NaOH | 39.997 |
Calcium hydroxide | Ca(OH)2 | 74.092 |
Ethanol | C2H5OH | 46.069 |
Hydrobromic acid | HBr | 80.912 |
Nitrous acid | HNO2 | 47.013 |
Potassium hydroxide | KOH | 56.11 |
Silver nitrate | AgNO3 | 169.872 |
Sodium carbonate | Na2CO3 | 105.988 |
Sodium chloride | NaCl | 58.44 |
Magnesium hydroxide | Mg(OH)2 | 58.319 |
Methane | CH4 | 16.043 |
Nitrogen dioxide | NO2 | 30.006 |
Sodium nitrate | NaNO3 | 84.994 |
Aluminium sulfate | Al2(SO4)3 | 342.15 |
Aluminium oxide | Al2O3 | 101.96 |
Ammonium nitrate | NH4NO3 | 80.043 |
Ammonium phosphate | (NH4)3PO4 | 132.056 |
Barium hydroxide | Ba(OH)2 | 171.341 |
Carbon tetrachloride | CCl4 | 153.811 |
Citric acid | C6H8O7 | 192.123 |
Hydrocyanic acid | HCN | 27.026 |
Salicylic Acid | C7H6O3 | 138.121 |
Hydroiodic acid | HI | 127.91 |
Hypochlorous acid | HClO | 52.457 |
Magnesium phosphate | Mg3(PO4)2 | 262.855 |
Sodium acetate | C2H3NaO2 | 82.0343 |
Sodium sulfate | Na2SO4 | 142.036 |
Sucrose | C12H22O11 | 342.2965 |
Potassium nitrate | KNO3 | 101.102 |
Ammonium bicarbonate | NH4HCO3 | 96.086 |
Ammonium chloride | NH4Cl | 53.489 |
Ammonium hydroxide | NH4OH | 35.046 |
Calcium nitrate | Ca(NO3)2 | 164.088 |
Calcium oxide | CaO | 56.0774 |
Carbon monoxide | CO | 28.01 |
Phenol | C6H6O | 94.11 |
Hydrogen peroxide | H2O2 | 34.0147 |
Magnesium chloride | MgCl2 | 95.211 |
Potassium chloride | KCl | 74.5513 |
Potassium iodide | KI | 166.0028 |
Sulfur dioxide | SO2 | 64.066 |
Calcium acetate | C4H6O4Ca | 158.17 |
Iron oxide | Fe2O3 | 159.69 |
Potassium carbonate | K2CO3 | 138.205 |
Silver chloride | AgCl | 143.318 |
Sodium iodide | NaI | 149.894 |
Sodium oxide | Na2O | 61.9789 |
Zinc nitrate | Zn(NO3)2 | 189.388 |
Magnesium nitrate | Mg(NO3)2 | 148.313 |
Silicon dioxide | SiO2 | 60.083 |
Ammonium acetate | C2H3O2NH4 | 77.083 |
Benzene | C6H6 | 78.11 |
Methyl Ethyl Ketone | C4H8O | 72.107 |
Trichloroacetic acid | C2HCl3O2 | 163.38 |
Magnesium sulfate | MgSO4 | 120.361 |
Methanol | CH3OH | 32.04 |
Sodium sulfite | Na2SO3 | 126.043 |
Sulfur trioxide | SO3 | 80.057 |
Aluminium phosphate | AlPO4 | 121.951 |
Dinitrogen monoxide | N2O | 44.013 |
Potassium dichromate | K2Cr2O7 | 294.185 |
Sodium bromide | NaBr | 102.894 |
Sodium hypochlorite | NaClO | 74.439 |
Zinc acetate | Zn(CH3COO)2(H2O)2 | 183.48 |
Zinc chloride | ZnCl2 | 136.286 |
Zinc hydroxide | Zn(OH)2 | 99.424 |
Magnesium carbonate | MgCO3 | 84.313 |
Potassium chlorate | KClO3 | 122.545 |
Hydrazine | N2H4 | 32.0452 |
Maleic acid | C4H4O4 | 116.072 |
Dichloromethane | CH2Cl2 | 84.93 |
Potassium chromate | CrK2O4 | 194.189 |
Zinc sulfate | ZnSO4 | 161.436 |
Aluminum | Al | 26.982 |
Perchloric acid | HClO4 | 100.46 |
Potassium Bromide | KBr | 119.002 |
Chromic acid | H2CrO4 | 118.01 |
Methyl acetate | C3H6O2 | 74.079 |
Hexane | C6H14 | 86.18 |
Manganese dioxide | MnO2 | 86.9368 |
Lactic acid | C3H6O3 | 90.078 |
Lithium hydroxide | LiOH | 23.95 |
Phosphorus pentachloride | PCl5 | 208.24 |
Potassium oxide | K2O | 94.2 |
Monopotassium phosphate | KH2PO4 | 136.084 |
Sodium fluoride | NaF | 41.98817 |
Sodium nitrite | NaNO2 | 68.9953 |
Barium carbonate | BaCO3 | 197.34 |
Calcium Iodide | CaI2 | 293.887 |
Lithium oxide | Li2O | 29.88 |
Potassium Permanganate | KMnO4 | 158.034 |
Silver phosphate | Ag3PO4 | 418.58 |
Ammonium bromide | NH4Br | 97.943 |
Calcium phosphate | Ca3(PO4)2 | 310.18 |
Ammonium carbonate | (NH4)2CO3 | 96.086 |
Barium chloride | BaCl2 | 208.23 |
Magnesium iodide | MgI2 | 278.1139 |
Ozone | O3 | 48 |
Potassium cyanide | KCN | 65.12 |
Silver oxide | Ag2O | 231.735 |
Sodium chromate | Na2CrO4 | 161.97 |
Sodium peroxide | Na2O2 | 77.98 |
Zinc carbonate | ZnCO3 | 125.388 |
Zinc phosphate | Zn3(PO4)2 | 386.11 |
Zinc sulfide | ZnS | 97.474 |
Boric acid | H3BO3 | 61.83 |
Potassium bicarbonate | KHCO3 | 100.114 |
Potassium hypochlorite | KClO | 90.55 |
Potassium nitrite | KNO2 | 85.103 |
Ammonium iodide | NH4I | 144.94 |
Ammonium nitrite | NH4NO2 | 64.06 |
Ammonium oxide | (NH4)2O | 52.0763 |
Barium bromide | BaBr2 | 297.14 |
Barium iodide | BaI2 | 391.136 |
Dinitrogen trioxide | N2O3 | 76.01 |
Ethylene glycol | C2H6O2 | 62.07 |
Nickel sulfate | NiSO4 | 154.75 |
Lithium chloride | LiCl | 42.394 |
Potassium fluoride | KF | 58.0967 |
Potassium sulfite | K2SO3 | 158.26 |
Silver carbonate | Ag2CO3 | 275.7453 |
Sodium cyanide | NaCN | 49.0072 |
Sodium nitride | Na3N | 82.976 |
Strontium chloride | SrCl2 | 158.52 |
Urea | CH4N2O | 60.056 |
Bleach | NaClO | 74.439 |
Lithium bromide | LiBr | 86.844 |
Aluminium fluoride | AlF3 | 83.9767 |
Barium fluoride | BaF2 | 175.34 |
Copper (II) carbonate | CuCO3 | 123.55 |
Fluorine | F | 18.998403 |
Lithium phosphate | Li3PO4 | 115.79 |
Lead Iodide | PbI2 | 461.01 |
Lithium iodide | LiI | 133.844 |
Magnesium oxide | MgO | 40.3044 |
Sodium dichromate | Na2Cr2O7 | 261.97l |
Tartaric acid | C4H6O6 | 150.087 |
Zinc iodide | ZnI2 | 319.22 |
Bromine | Br | 54.9380 |
Aluminum bromide | AlBr3 | 266.69 |
Sodium Percarbonate | C2H6Na4O12 | 157.01 |
Nickel acetate | C4H6O4Ni | 178.797 |
Acetaldehyde | C2H4O | 44.05 |
Copper sulfate | CuSO4 | 159.609 |
Calcium Chloride | CaCl2 | 110.98 |
Sodium Chlorate | NaClO3 | 106.44 |
Potassium Iodate | KIO3 | 214.001 |
Lead Acetate | Pb(C2H3O2)2 | 325.29 |
Formaldehyde | CH2O | 30.031 |
Formic Acid | HCOOH | 46.03 |
Sulfur Hexafluoride | SF6 | 146.06 |
Ethane | C2H6 | 30.07 |
Dinitrogen Pentoxide | N2O5 | 30.07 |
Phosphorous Acid | H3PO3 | 82 |
Aluminium hydroxide | Al(OH)3 | 78.00 |
Potassium acetate | CH3CO2K | 98.142 |
Barium oxide | BaO | 153.326 |
Copper(I) Oxide | Cu2O | 143.09 |
Copper Hydroxide | Cu(OH)2 | 97.561 |
Ethylene | C2H4 | 28.054 |
Acetylene | C2H2 | 26.038 |
Chromic Oxide | Cr2O3 | 151.9904 |
Sodium bisulfate | NaHSO4 | 120.06 |
Copper (II) chloride | CuCl2 | 134.45 |
Mercuric chloride | HgCl2 | 271.52 |
Tin (II) chloride | SnCl2 | 189.60 |
Propane | C3H8 | 44.097 |
Lead (IV) oxide | PbO2 | 239.1988 |
Also, Check
FAQs on Chemical Formula
Define Chemical Formula?
The term chemical formula is used to define the chemical composition of any compound. It tells us about the elements a compound has, it also tells us about the ratio in which these elements combine.
What is Chemical Formula of Ozone?
Chemical formula of ozone is O3. In ozone three oxygen atoms are combined with each other.
What is Chemical Formula of Rust?
Chemical formula of rust is Fe2O3. Its scientific name is Ferric Oxide.
What is Chemical Formula of Baking Soda?
Chemical formula of baking soda is NaHCO3. Its scientific name is sodium bicarbonate.
What is Chemical Formula of Bleaching Powder?
Chemical formula of bleaching powder is CaOCl2. Its scientific name is calcium oxychloride.
What is Chemical Formula of Washing Soda?
Chemical formula of washing soda is NaCO3. Its scientific name is sodium carbonate.
What is Chemical Formula of Calcium Carbonate?
Chemical formula of calcium carbonate is CaCO3. The common name of calcium carbonate is Chalk.
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