Q. How many molecules are present in 1 mole of oxygen (O₂)?
Answer:
6.022 × 10²³
Notes: 1 mole of any substance contains Avogadro’s number of particles, which is 6.022 × 10²³. Therefore, 1 mole (32 g) of O₂ has 6.022 × 10²³ molecules. This is a fundamental constant in chemistry known as Avogadro's number.