CHEMITRY CALCULATOR
Molecular Weight
A precise tool.
What is the Molecular Weight & How does it work?
The molecular weight of a substance is the sum of the atomic weights of all atoms in its chemical formula. This value is crucial for stoichiometric calculations and understanding the composition of compounds.For example, the molecular weight of water (H2O) is calculated as: 2 × 1.008 (for hydrogen) + 16.00 (for oxygen) = 18.016 g/mol.
M = sum (n_i times A_i)
M = Molecular Weight, ni = Number of atoms of element i, Ai = Atomic Weight of element i
Parameters
Result
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Frequently Asked Questions
How do I calculate the molecular weight of a compound?
Multiply the number of atoms of each element by its atomic weight, then sum these products.
What is the molecular weight of water (H2O)?
The molecular weight of water is 18.016 g/mol, calculated as 2 × 1.008 (for hydrogen) + 16.00 (for oxygen).
Can I use this calculator for complex compounds?
Yes, you can input any chemical formula to find its molecular weight, including those with multiple elements and subscripts.
What is the difference between atomic weight and molecular weight?
Atomic weight is the average weight of an element’s isotopes, while molecular weight is the sum of all atoms’ weights in a molecule.
Why is molecular weight important in chemistry?
Molecular weight is crucial for stoichiometric calculations, balancing chemical equations, and understanding compound properties.
Can this calculator handle isotopic variations?
This calculator typically uses standard atomic weights. For isotopic variations, you may need to manually adjust the atomic weights accordingly.
Results are for informational purposes only and do not constitute professional advice.