1. What is Relative Molecular Mass?

Relative Molecular Mass (RMM), also known as molecular weight, is the sum of the atomic masses of all atoms in a molecule. It's expressed in atomic mass units (amu) and is dimensionless.

2. How to Calculate RMM

The calculation follows this basic formula:

Steps:

1. Identify all atoms in the chemical formula
2. Find each element's atomic mass from the periodic table
3. Multiply each atomic mass by the number of atoms of that element
4. Sum all the values

3. Importance of RMM Calculation

Applications: RMM is essential for stoichiometric calculations, preparing molar solutions, determining empirical formulas, and understanding reaction yields in chemistry.

4. Using the Calculator

Instructions: Enter the chemical formula using standard notation (e.g., H2O for water, C6H12O6 for glucose). The calculator will sum the atomic masses of all atoms in the formula.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between RMM and molar mass?
A: RMM is dimensionless (relative to 1/12th of carbon-12), while molar mass has units of g/mol. Numerically they're equal.

Q2: How do I calculate RMM for hydrated compounds?
A: Include the water molecules in the formula (e.g., CuSO4·5H2O) and calculate as normal.

Q3: What about ionic compounds?
A: For ionic compounds like NaCl, we calculate formula mass (sum of atomic masses) the same way.

Q4: How accurate is this calculator?
A: It uses standard atomic weights. For precise work, use isotope-specific masses.

Q5: Can it handle complex formulas?
A: This version handles simple formulas. Complex formulas with parentheses or charges require more advanced parsing.