Calculation: A Molecular Weight Calculator is an essential tool in chemistry that helps determine the molecular weight (also known as molecular mass) of a compound or molecule based on its chemical formula.
What is a Molecular Weight Calculator?
The Molecular Weight Calculator is used to calculate the mass of a molecule by adding the individual atomic weights of the elements that make up the molecule. It helps in determining the molecular mass of a compound, which is crucial for many applications in chemistry, including chemical reactions, stoichiometry, and pharmaceutical formulations.
Molecular Weight Calculator Formula
To calculate the molecular weight, you need to know the chemical formula of the molecule. The formula involves adding the atomic weights of all the atoms present in the molecule.
Molecular Weight Formula:
Molecular Weight = (Number of atoms of element 1 × Atomic weight of element 1) + (Number of atoms of element 2 × Atomic weight of element 2) + ...This process continues for each element in the molecule. For example, the molecular weight of water (H₂O) is calculated by adding the atomic weights of hydrogen (H) and oxygen (O), considering the number of atoms of each element.
Molecular Weight Calculator Example
Here are two examples to help you understand how the Molecular Weight Calculator works:
Example 1: Calculating the Molecular Weight of Water (H₂O)
Step 1: Write down the chemical formula:
- Chemical Formula: H₂O
Step 2: Identify the atomic weights:
- Atomic weight of Hydrogen (H) = 1.008 g/mol
- Atomic weight of Oxygen (O) = 15.999 g/mol
Step 3: Apply the formula:
- Molecular Weight = (2 × 1.008) + (1 × 15.999)
- Molecular Weight = 2.016 + 15.999 = 18.015 g/mol
Thus, the molecular weight of water is 18.015 g/mol.
Example 2: Calculating the Molecular Weight of Carbon Dioxide (CO₂)
Step 1: Write down the chemical formula:
- Chemical Formula: CO₂
Step 2: Identify the atomic weights:
- Atomic weight of Carbon (C) = 12.011 g/mol
- Atomic weight of Oxygen (O) = 15.999 g/mol
Step 3: Apply the formula:
- Molecular Weight = (1 × 12.011) + (2 × 15.999)
- Molecular Weight = 12.011 + 31.998 = 44.009 g/mol
Thus, the molecular weight of carbon dioxide is 44.009 g/mol.
Element Table
This table contains the symbols, names, and atomic weights (in g/mol) of elements.
| Symbol | Name | Atomic Weight (g/mol) |
|---|---|---|
| H | Hydrogen | 1.00794 g/mol |
| He | Helium | 4.002602 g/mol |
| Li | Lithium | 6.941 g/mol |
| Be | Beryllium | 9.012182 g/mol |
| B | Boron | 10.811 g/mol |
| C | Carbon | 12.0107 g/mol |
| N | Nitrogen | 14.0067 g/mol |
| O | Oxygen | 15.9994 g/mol |
| F | Fluorine | 18.9984032 g/mol |
| Ne | Neon | 20.1797 g/mol |
| Na | Sodium | 22.98976928 g/mol |
| Mg | Magnesium | 24.3050 g/mol |
| Al | Aluminum | 26.9815386 g/mol |
| Si | Silicon | 28.0855 g/mol |
| P | Phosphorus | 30.973762 g/mol |
| S | Sulfur | 32.065 g/mol |
| Cl | Chlorine | 35.453 g/mol |
| Ar | Argon | 39.948 g/mol |
| K | Potassium | 39.0983 g/mol |
| Ca | Calcium | 40.078 g/mol |
| Sc | Scandium | 44.955912 g/mol |
| Ti | Titanium | 47.867 g/mol |
| V | Vanadium | 50.9415 g/mol |
| Cr | Chromium | 51.9961 g/mol |
| Mn | Manganese | 54.938045 g/mol |
| Fe | Iron | 55.845 g/mol |
| Co | Cobalt | 58.933195 g/mol |
| Ni | Nickel | 58.6934 g/mol |
| Cu | Copper | 63.546 g/mol |
| Zn | Zinc | 65.409 g/mol |
| Ga | Gallium | 69.723 g/mol |
| Ge | Germanium | 72.64 g/mol |
| As | Arsenic | 74.92160 g/mol |
| Se | Selenium | 78.96 g/mol |
| Br | Bromine | 79.904 g/mol |
| Kr | Krypton | 83.798 g/mol |
| Rb | Rubidium | 85.4678 g/mol |
| Sr | Strontium | 87.62 g/mol |
| Y | Yttrium | 88.90585 g/mol |
| Zr | Zirconium | 91.224 g/mol |
| Nb | Niobium | 92.90638 g/mol |
| Mo | Molybdenum | 95.94 g/mol |
| Tc | Technetium | 98.9063 g/mol |
| Ru | Ruthenium | 101.07 g/mol |
| Rh | Rhodium | 102.90550 g/mol |
| Pd | Palladium | 106.42 g/mol |
| Ag | Silver | 107.8682 g/mol |
| Cd | Cadmium | 112.411 g/mol |
| In | Indium | 114.818 g/mol |
| Sn | Tin | 118.710 g/mol |
| Sb | Antimony | 121.760 g/mol |
| Te | Tellurium | 127.60 g/mol |
| I | Iodine | 126.90447 g/mol |
| Xe | Xenon | 131.293 g/mol |
| Cs | Cesium | 132.9054519 g/mol |
| Ba | Barium | 137.327 g/mol |
| La | Lanthanum | 138.90547 g/mol |
| Ce | Cerium | 140.116 g/mol |
| Pr | Praseodymium | 140.90765 g/mol |
| Nd | Neodymium | 144.242 g/mol |
| Pm | Promethium | 146.9151 g/mol |
| Sm | Samarium | 150.36 g/mol |
| Eu | Europium | 151.964 g/mol |
| Gd | Gadolinium | 157.25 g/mol |
| Tb | Terbium | 158.92535 g/mol |
| Dy | Dysprosium | 162.500 g/mol |
| Ho | Holmium | 164.93032 g/mol |
| Er | Erbium | 167.259 g/mol |
| Tm | Thulium | 168.93421 g/mol |
| Yb | Ytterbium | 173.04 g/mol |
| Lu | Lutetium | 174.967 g/mol |
| Hf | Hafnium | 178.49 g/mol |
| Ta | Tantalum | 180.9479 g/mol |
| W | Tungsten | 183.84 g/mol |
| Re | Rhenium | 186.207 g/mol |
| Os | Osmium | 190.23 g/mol |
| Ir | Iridium | 192.217 g/mol |
| Pt | Platinum | 195.084 g/mol |
| Au | Gold | 196.966569 g/mol |
| Hg | Mercury | 200.59 g/mol |
| Tl | Thallium | 204.3833 g/mol |
| Pb | Lead | 207.2 g/mol |
| Bi | Bismuth | 208.98040 g/mol |
| Po | Polonium | 208.9824 g/mol |
| At | Astatine | 209.9871 g/mol |
| Rn | Radon | 222.0176 g/mol |
| Fr | Francium | 223.0197 g/mol |
| Ra | Radium | 226.0254 g/mol |
| Ac | Actinium | 227.0278 g/mol |
| Th | Thorium | 232.03806 g/mol |
| Pa | Protactinium | 231.03588 g/mol |
| U | Uranium | 238.02891 g/mol |
| Np | Neptunium | 237.0482 g/mol |
| Pu | Plutonium | 244.0642 g/mol |
| Am | Americium | 243.0614 g/mol |
| Cm | Curium | 247.0703 g/mol |
| Bk | Berkelium | 247.0703 g/mol |
| Cf | Californium | 251.0796 g/mol |
| Es | Einsteinium | 252.0829 g/mol |
| Fm | Fermium | 257.0951 g/mol |
| Md | Mendelevium | 258.0986 g/mol |
| No | Nobelium | 259.1009 g/mol |
| Lr | Lawrencium | 260.1053 g/mol |
| Rf | Rutherfordium | 261.1087 g/mol |
| Db | Dubnium | 262.1138 g/mol |
| Sg | Seaborgium | 263.1182 g/mol |
| Bh | Bohrium | 262.1229 g/mol |
| Hs | Hassium | 265 g/mol |
| Mt | Meitnerium | 266 g/mol |
| Ds | Darmstadtium | 269 g/mol |
| Rg | Roentgenium | 272 g/mol |
| Uub | Ununbium | 285 g/mol |
| Uut | Ununtrium | 284 g/mol |
| Uuq | Ununquadium | 289 g/mol |
| Uup | Ununpentium | 288 g/mol |
| Uuh | Ununhexium | 292 g/mol |
| Uuo | Ununoctium | 294 g/mol |
The Molecular Weight Calculator is an invaluable tool in chemistry, helping to accurately determine the molecular weight of various compounds. Whether you are studying chemical reactions or working on pharmaceutical formulas, this tool allows for quick and accurate calculations, ensuring precision in your work.