1. What is the Mole Equation?

The mole equation (n = m/A_r) relates the amount of substance in moles to its mass and relative atomic/molecular mass. It's a fundamental concept in chemistry for quantitative calculations.

2. How Does the Calculator Work?

The calculator uses the mole equation:

Where:

• \( n \) — Amount of substance (moles)
• \( m \) — Mass of substance (grams)
• \( A_r \) — Relative atomic/molecular mass (g/mol)

Explanation: The equation shows how to convert between mass and moles using the substance's atomic or molecular weight.

3. Importance of Mole Calculations

Details: Mole calculations are essential for balancing chemical equations, determining reaction yields, preparing solutions, and stoichiometric calculations in chemistry.

4. Using the Calculator

Tips: Enter the mass in grams and the relative atomic/molecular mass in g/mol. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a mole in chemistry?
A: A mole is the SI unit for amount of substance, defined as containing exactly 6.022×10²³ (Avogadro's number) of particles (atoms, molecules, ions, etc.).

Q2: How do I find the relative atomic mass?
A: The relative atomic mass (A_r) can be found on the periodic table for elements. For compounds, add up the A_r values of all atoms in the formula.

Q3: Can I use this for molecular substances?
A: Yes, just use the relative molecular mass (M_r) instead of A_r for molecular compounds.

Q4: What units should I use?
A: Mass must be in grams (g) and relative atomic mass in grams per mole (g/mol) for the equation to work correctly.

Q5: How precise should my answer be?
A: For GCSE purposes, 2-4 decimal places are usually sufficient, unless specified otherwise in the question.