1. What is Exact Mass?

Exact mass is the calculated mass of an ion or molecule based on the most abundant isotopes of each element. It differs from molecular weight, which uses average atomic masses. Exact mass is particularly important in mass spectrometry for identifying compounds.

2. How Does the Calculator Work?

The calculator uses the exact mass formula:

Where:

• Number of Atoms — Count of each element in the molecule
• Exact Mass of Isotope — Mass of the most abundant isotope for each element

Explanation: The calculator parses the molecular formula and sums the product of atom counts and their respective isotope masses.

3. Importance of Exact Mass Calculation

Details: Exact mass calculation is crucial in mass spectrometry for compound identification, metabolomics studies, and verifying molecular structures in chemical research.

4. Using the Calculator

Tips: Enter the molecular formula using standard notation (e.g., H2O, C6H12O6). Element symbols are case-sensitive (first letter uppercase, second lowercase).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between exact mass and molecular weight?
A: Exact mass uses the mass of the most abundant isotope of each element, while molecular weight uses the average atomic mass weighted by natural abundance.

Q2: Why is exact mass important in mass spectrometry?
A: High-resolution mass spectrometers can measure mass with such precision that the exact mass can be used to determine elemental composition.

Q3: Which elements are supported by this calculator?
A: The calculator currently supports H, C, N, O, F, P, S, Cl, Br, and I with their most abundant isotopes.

Q4: How accurate is this calculator?
A: The calculator uses established isotope masses and provides results accurate to 6 decimal places, sufficient for most applications.

Q5: Can I use this for ions and charged molecules?
A: This calculator provides the neutral mass. For ions, you would need to adjust for the mass of electrons gained or lost.