Molecular Weight Calculator
Calculate molecular weight and molar mass of chemical compounds
Understanding Molecular Weight
Molecular weight (MW) is the sum of atomic weights of all atoms in a molecule. Our calculator helps you determine molecular weights by analyzing chemical formulas using accurate atomic mass values.
Molecular Weight Calculator
Calculate molecular mass of chemical compounds
Use capital letters for elements (e.g., Na for sodium)
Understanding Molecular Weight
Molecular Mass
Understanding molecular weight calculations
- Sum of atomic masses
- Mass per mole
- Isotopic considerations
- Unit conversions
Formula Analysis
How to analyze chemical formulas
- Element identification
- Subscript interpretation
- Polyatomic ions
- Empirical formulas
Applications
Uses of molecular weight
- Solution preparation
- Stoichiometry
- Concentration calculations
- Chemical analysis
Frequently Asked Questions
What is molecular weight?
Molecular weight (MW) is the sum of the atomic weights of all atoms in a molecule. It represents the mass of one mole of a substance and is typically expressed in grams per mole (g/mol).
How do you calculate molecular weight?
To calculate molecular weight, identify each element in the chemical formula, multiply its atomic mass by the number of atoms present, and sum all these products. For example, for H2O: (2 × H) + (1 × O) = (2 × 1.008) + (1 × 15.999) = 18.015 g/mol.
What is the difference between molecular weight and molar mass?
Molecular weight and molar mass are numerically identical but have different contexts. Molecular weight is a dimensionless relative mass, while molar mass is expressed in g/mol and represents the mass of one mole of a substance.
How is molecular weight used in chemistry?
Molecular weight is essential for stoichiometry calculations, determining solution concentrations, calculating gas properties, and preparing chemical solutions. It's a fundamental concept in quantitative chemistry.
What is empirical formula and how is it related to molecular weight?
An empirical formula shows the simplest whole-number ratio of atoms in a compound. The molecular weight helps determine the relationship between empirical and molecular formulas, as the molecular formula is often a multiple of the empirical formula.
Important Notes
- Uses atomic mass values from periodic table
- Supports complex chemical formulas
- Handles polyatomic ions
- Shows mass contribution of each element
- Important for stoichiometry calculations
- Essential for solution concentration