1. What is the Mole Formula?

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

2. How Does the Calculator Work?

The calculator uses the mole formula:

Where:

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

Explanation: The formula converts between mass and moles using the substance's atomic or molecular weight as a conversion factor.

3. Importance of Mole Calculations

Details: Mole calculations are essential for stoichiometry, determining reactant quantities, product yields, and understanding chemical reactions at the molecular level.

4. Using the Calculator

Tips: Enter mass in grams and relative atomic/molecular mass in g/mol. Both values must be positive numbers. For compounds, use the sum of atomic masses.

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) is found on the periodic table for elements. For compounds, sum the A_r values of all atoms in the formula.

Q3: Can this be used for solutions?
A: For solutions, use concentration (mol/dm³) instead. The formula would be n = C × V (concentration × volume in dm³).

Q4: Why is the mole concept important?
A: It allows chemists to count particles by weighing, making practical measurements possible at the atomic scale.

Q5: What's the difference between A_r and M_r?
A: A_r is relative atomic mass (for elements), while M_r is relative molecular mass (for compounds). Both are in g/mol.