Chemistry Formulas

Chemistry Formulas

The branch of science dealing with the chemical as well as physical properties of substances in a manner that further results in the formation of new substances is known as Chemistry. All elements of nature that so far exist have a specific name that has been derived through the studies of chemistry. The formulas of Chemistry are known as the chemical formulas.

A chemical formula is a way through which scientists represent the chemical proportions such as the number of atoms present in a molecule or a chemical compound. It is done with the help of chemical elements, their symbols and the numerical subscripts. The chemistry formulas can be understood through the chemistry formula table.

Types of Chemistry Formulae or Chemical Formulae

There are three types of chemical formulae:

  • Molecular Formula
  • Empirical Formula
  • Structural Formula

Molecular Formula: Molecular formula also known as true formula provides us with the exact number of atoms of every element present in a molecule. The numerical subscripts after the chemical symbols denote the total number of atoms present. The molecular formula also tells us about the type of atom present in a molecule of a compound. Below is an example of a molecular formula.

Molecular Formula of glucose: C₆H₁₂O₆ 

It represents the actual number of atoms of each constituent (Carbon, Hydrogen and Oxygen) in one molecule of glucose.

Empirical Formula: The word empirical represents something that can be assessed through observation. As such the empirical formula which is more than often emanated from experimental data is defined as the simplest ratio of all the atoms present in the elements that make up a compound. An example of empirical formula extracted by simplifying the molecular formula of glucose:

Empirical formula of glucose: CH₂O

It represents the whole ratio number of the atoms present that is, C, H and O

Structural Formula: While it is good to have chemical formulas in an easy and compact manner, it is also important to know the arrangements of atoms in them. The structural formula tells us about atomic bonding and their arrangement in spaces. It helps us to identify which atoms are bonded with one another and which are not. Given below is an example of the structural formula of glucose which represents the atomic bonding and arrangement.

How to Write Chemical Formulas?

A chemical formula can be written by the name of the elements that constitute a compound along with some basic rules and in a reverse manner.

  1. Chemical formulas of binary compounds which are made of two different elements can be written with the help of valency.
  2. The capacity of the combination of the elements to form a compound or compound is known as valency. 
  3. Firstly the valencies of the two elements should be determined and then the sums of the valencies of the two different elements should be made equal by specifying the common lowest multiple of the two valencies. 
  4. Cation is an atom with positive charge and anion is an atom with a negative charge. In case if a metal and non-metal are present, the metal should be placed first in the formula. For example NaCl, in which Na has a positive charge and Cl has a negative charge.

Let’s take an example of balanced 

Aluminium oxide:

O = 2 (belongs to group VI)

Al = 3 (belongs to group III)


Lowest common multiple of the valencies is 6,

O : 2 x 3 = 6

Al : 3x 2 = 6


The chemical formula of Aluminium oxide is Al₂O₃

Steps to Write a Chemical Reaction

It is important to note that balancing of chemical equations plays a major role in this process.  Basically, four rules are followed while writing a chemical equation. Let’s have a look below, 

  1. On the left side of the equation, the right number of reactants is written.
  2. On the right side of the equation, the right formulas constituting the products are written.
  3. Both the reactants and the products are partitioned by an arrow which points towards the products. This arrow indicates “to produce”.
  4. With the help of plus signs various products and reactants are separated. The plus sign indicates ” reacts with” on the reactants side and it means “and”  on the products side.

Let’s take an example of a balanced chemical reaction where hydrogen and chlorine will react to make HCl.

The first step involves writing the equation in terms of the formulas of both the elements, both of which are diatomic in nature.

H2 + Cl2 → HCl 

There are two hydrogen atoms and chlorine atoms on the reactants side and one atom each on the product which can be now fixed and balanced by the inclusion of the coefficient 2 on the side of the product.

H2 + Cl2 → 2HCl

Now both the sides are balanced having two hydrogen and chlorine atoms each.

Some examples of chemical reactions are listed below:

Photosynthesis: 6CO2 + 6H2O  → C6H12O6 + 6O2 + 6H2O

Calcium carbonate formation: CaCl2 + Na2CO3 → CaCO3 + 2NaCl

Iron rusting: 4Fe + 3O2 + 6H2O → 4Fe(OH)3.

Combustion of hydrogen: 2H2(g) + O2(g) → 2H2O(l ) 

Table of Chemical Formulas (Molecular)

Compound Name Molecular Formulae
Acetic acid CH3COOH
Hydrochloric acid HCl
Sulfuric acid H2SO4
Acetate CH3COO–
Ammonia NH3
Nitric acid HNO3
Phosphoric acid H3PO4
Sodium phosphate Na3PO4
Calcium carbonate CaCO3
Ammonium sulfate (NH4)2SO4
Carbonic acid H2CO3
Sodium bicarbonate NaHCO3
Sodium hydroxide NaOH
Calcium hydroxide Ca(OH)2
Ethanol C2H5OH
Hydrobromic acid HBr
Nitrous acid HNO2
Potassium hydroxide KOH
Silver nitrate AgNO3
Sodium carbonate Na2CO3
Sodium chloride NaCl
Cellulose (C6H10O5)n
Magnesium hydroxide Mg(OH)2
Methane CH4
Nitrogen dioxide NO2
Sodium nitrate NaNO3
Sulfurous acid H2SO3
Aluminium sulfate Al2(SO4)3
Aluminium oxide Al2O3
Ammonium nitrate NH4NO3
Ammonium phosphate (NH4)3PO4
Barium hydroxide Ba(OH)2
Carbon tetrachloride CCl4
Citric acid C6H8O7
Hydrocyanic acid HCN
Salicylic Acid C7H6O3
Hydroiodic acid HI
Hypochlorous acid HClO
Iron iii oxide Fe2O3
Magnesium phosphate Mg3(PO4)2


List of Chemical Compound Formulas

Compounds are basically substances that constitute two elements or more in a definite percentage. With the help of chemical formulas, the atoms of the elements in a compound can be known. The list below shows some chemical compounds along with their chemical formulas.

Sl.No Chemical Compound Chemical Formula
1 Acetic acid formula CH3COOH
2 Aluminium hydroxide  Al(OH)3
3 Acetate  CH3COO¯
4 Acetone  C3H₆O
5 Aluminium acetate C₆H₉AlO₆
6 Aluminium bromide  AlBr3
7 Aluminium carbonate  Al2(CO3)3
8 Aluminium chloride  AlCl3
9 Aluminium fluoride  AlF3
10 Aluminium  Al
11 Aluminium iodide  AlI3
12 Aluminium oxide  Al2O3
13 Aluminium phosphate AlPO₄
14 Amino acid  H2NCHRCOOH
15 Ammonia  NH₄
16 Ammonium dichromate  Cr2H₈N2O₇
17 Ammonium acetate C2H3O2NH₄
18 Ammonium bicarbonate NH₄HCO3
19 Ammonium bromide NH₄Br
20 Ammonium carbonate  (NH₄)2CO3
21 Ammonium chloride  NH₄Cl
22 Ammonium hydroxide  NH₄OH
23 Ammonium iodide  NH₄I
24 Ammonium nitrate  NH₄NO3
25 Aluminium sulfide Al2S3
26 Ammonium nitrite  NH₄NO2
27 Ammonium oxide  (NH₄)2O
28 Ammonium phosphate  (NH₄)3PO₄
29 Ammonium sulfate  (NH₄)2SO₄
30 Ammonium sulfide  (NH₄)2S
31 Argon gas  Ar
32 Ascorbic acid  C₆H₈O₆
33 Barium acetate  Ba(C₂H3O2)2
34 Barium bromide  BaBr2
35 Barium chloride BaCl2
36 Barium fluoride  BaF2
37 Barium hydroxide  Ba(OH)2
38 Barium iodide  BaI2
39 Barium nitrate Ba(NO3)2
40 Barium oxide  BaO
41 Barium phosphate Ba3O₈P2
42 Barium sulfate  BaSO₄
43 Benzene  C₆H₆
44 Benzoic acid  C₇H₆O2
45 Bicarbonate  CHO3¯
46 Bleach  NaClO
47 Boric acid  H3BO3
48 Potassium Bromate KBrO3
49 Bromic acid  HBrO3
50 Bromine  Br
51 Butane  C₄H₁₀
52 Butanoic acid  C₄H₈O2
53 Calcium acetate  C₄H₆CaO₄
54 Calcium bromide  CaBr2
55 Calcium carbonate  CaCO3
56 Calcium hydride  CaH2
57 Calcium hydroxide  Ca(OH)2
58 Calcium iodide  CaI2
59 Calcium nitrate Ca(NO3)2
60 Calcium oxide  CaO
61 Carbon monoxide  CO
62 Carbon tetrachloride  CCl₄
63 Carbonic acid  H2CO3
64 Calcium phosphate  Ca3(PO₄)2
65 Carbonic acid  H2CO3
66 Citric acid  C₆H₈O₇
67 Chlorate  ClO3¯
68 Chlorine  Cl
69 Chlorine gas  Cl2
70 Chlorous acid  HClO2
71 Chromate CrO₄²¯
72 Chromic acid H2CrO₄
73 Citric acid  C₆H₈O₇
74 Copper ii carbonate  CuCO3
75 Copper ii nitrate  Cu(NO3)2
76 Cyanide  CN¯
77 Dichromate K2Cr2O₇
78 Dihydrogen monoxide OH2
79 Dinitrogen monoxide  N2O
80 Dinitrogen pentoxide N2O₅
81 Dinitrogen trioxide  N2O3
82 Ethanol  C2H₅OH
83 Iron oxide Fe2O3
84 Ethylene glycol C2H₆O2
85 Fluorine gas  F2
86 Aluminium bromide AlBr3
87 Aluminium sulphide Al2S3
88 Ammonium carbonate (NH₄)2CO3
89 Ammonium nitrate (NH₄)(NO3)
90 Ammonium phosphate (NH₄)3PO₄
91 Barium chloride  BaCl2
92 Barium sulphate BaSO₄
93 Calcium nitrate Ca(NO3)2
94 Carbon monoxide CO
95 Carbon tetrachloride CCl₄
96 Carbonic acid H2CO3
97 Hydrofluoric acid  HF
98 Hydroiodic acid HI
99 Hypochlorous acid  HClO
100 Lithium phosphate  Li3PO₄
101 Magnesium nitrate  MgNO3
102 Magnesium phosphate  Mg3(PO₄)2
103 Nitrogen monoxide  NO
104 Nitrous acid  HNO2
105 Potassium carbonate  K2CO3
106 Potassium iodide  KI
107 Potassium nitrate  KNO3
108 Potassium phosphate  KH2PO₄
109 Sodium carbonate  Na2CO₄
110 Sodium oxide  Na2O
111 Fructose chemical  C₆H₁2O₆
112 Glycerol  C3H₈O3
113 Helium gas  He
114 Hexane  C₆H₁₄
115 Hydrobromic acid  HBr
116 Hydrochloric acid  HCl
117 Hydrocyanic acid  HCN
118 Hydrofluoric acid HF
119 Hydrogen carbonate  CHO3¯
120 Hydrogen gas  H2
121 Hydrogen peroxide  H2O2
122 Hydrogen phosphate  H3PO₄
123 Hydrogen sulphate  HSO₄¯
124 Hydroiodic acid  HI
125 Hydrosulfuric acid  H2SO₄
126 Hydroxide  OH¯
127 Hypobromous acid  HBrO
128 Hypochlorite  NaClO
129 Hypochlorous acid  HClO
130 Hypoiodous acid  HIO
131 Iodic acid  HIO3
132 Iodide 
133 Iodine  I₂
134 Iron iii nitrate  Fe(NO3)3
135 Iron ii oxide  FeO
136 Iron iii carbonate  Fe2(CO3)3
137 Iron iii hydroxide  Fe(OH)3
138 Iron iii oxide  Fe2O3
139 Iron iii chloride  FeCl3
140 Lactic acid  C3H6O3
141 Lead acetate  Pb(C2H3O2)2
142 Lead ii acetate  Pb(C2H3O2)2
143 Lead iodide  PbI2
144 Lead iv oxide  PbO2
145 Lead nitrate  Pb(NO3)2
146 Lithium bromide LiBr
147 Lithium chloride LiCl2
148 Lithium hydroxide  LiOH
149 Lithium iodide  LiI
150 Lithium oxide  Li2O
151 Lithium phosphate  Li3PO4
152 Magnesium acetate  Mg(CH3COO)2
153 Magnesium bicarbonate  C2H2MgO6
154 Magnesium carbonate  MgCO3
155 Magnesium chloride MgCl2
156 Magnesium hydroxide Mg(OH)2
157 Magnesium iodide MgI2
158 Magnesium nitrate Mg(NO3)2
159 Magnesium nitride  Mg3N2
160 Magnesium carbonate  MgCO3
161 Magnesium bromide  MgBr2
162 Magnesium oxide  MgO
163 Magnesium phosphate  Mg3(PO4)2
164 Magnesium sulphate  MgSO4
165 Magnesium sulphide  MgS
166 Methane  CH4
167 Methanol  CH3OH
168 Nickel acetate  Ni(C2H3O2)2
169 Nickel nitrate  Ni(NO3)2
170 Nitric acid  HNO3
171 Nitride  N3–
172 Nitrite  NO2−
173 Nitrogen dioxide  NO2
174 Nitrogen monoxide  NO
175 Nitrous acid  HNO2
176 Oxalate  C2O42¯
177 Oxalic acid  H2C2O4
178 Oxygen  O2
179 Ozone  O3
180 Perbromic acid  HBrO4
181 Potassium Permanganate  KMnO4
182 Permanganate ion  MnO4–
183 Phosphate  PO43-
184 Sodium hydrogen phosphate  Na2HPO4
185 Sodium formate  CHNaO2
186 Phosphoric acid  H3PO4
187 Phosphorus pentachloride  PCl5
188 Phosphorus trichloride  PCl3
189 Potassium acetate  CH3CO2K
190 Potassium bicarbonate  KHCO3
191 Potassium carbonate  K2CO3
192 Potassium chlorate  KClO3
193 Potassium hydrogen phosphate  K2HPO4
194 Potassium chloride  KCl
195 Potassium chromate  CrK2O4
196 Potassium cyanide  KCN
197 Potassium dichromate  K2Cr2O7
198 Potassium fluoride  KF
199 Potassium hydroxide  KOH
200 Potassium hypochlorite  KClO