高效準確的化學工具

分子量與 摩爾質量計算器

輸入任意化學式即可計算其分子量、摩爾質量、元素質量百分比及原子個數，精確至4位小數。

104.5°OHHH₂O · 18.015 g/mol
118種元素
IUPAC 標準原子量
4位小數
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分子量
支援所有118種元素 · IUPAC 2021 標準原子量
快速範例:
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在上方輸入化學式以計算分子量

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18.02g/mol
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Hydrogen (H)2.016 g/mol11.2%
Oxygen (O)15.999 g/mol88.8%
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Ca(OH)₂
↓
Ca × 1O × 2H × 2
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H₂O
18.0150g/mol
H2 × 1.008
2.01611.2%
O1 × 15.999
15.99988.8%
Σ Total18.0150 g/mol
FAQ

Frequently Asked Questions

Find answers to common questions about molecular weight calculations and chemistry formulas.

Molecular weight is the sum of the atomic weights of all atoms in a chemical formula, expressed in g/mol or Daltons (Da).
Multiply each element's atomic weight by its atom count in the formula and sum the total.
Molecular weight measures a single molecule in Daltons while molar mass measures one mole in g/mol; both share equal numerical values.
Molecular weight is measured in grams per mole (g/mol), Daltons (Da), or atomic mass units (amu).
This calculator uses standard IUPAC 2021 atomic weights precise to 4 decimal places.
Calculations are accurate to 4 decimal places following official IUPAC 2021 standards.
Yes, this calculator is 100% free to use with no sign-up or usage limits.