Federal Board Chemistry Home Tutors in DHA Islamabad for FSc & Matric Students

A mole is a counting unit — like a dozen, but for 6.022 × 10²³ particles (Avogadro’s number). Chemists use it because atoms are too small to count individually.

Three linked ideas

• 1 mole of particles = Avogadro’s number of those particles
• Mass of 1 mole in grams = relative atomic/molecular mass in grams
• For gases at the same temperature and pressure, equal moles occupy equal volumes (ideal approximation)

Example: 18 g of water is about 1 mole of H₂O molecules — far more molecules than you could count, but a measurable mass.

Federal Board Chemistry tuition in DHA Islamabad can build every stoichiometric calculation from “how many moles?” first.