Convert into mole: (a) 12g of oxygen gas (b) 20g of water (c) 22g of carbon dioxide

(a) Molecular weight of oxygen in grams = 32 g of oxygen = one mole of oxygen gas
Thus, 12 g of oxygen = (1/32) × 12 = 0.375 moles
(b) Molecular weight of water (H₂O) in grams = 2 + 16 = 18 g = one mole of water
Thus, 20 g of water = (1/18) × 20 = 1.111 moles
(c) Molecular weight of carbon dioxide (CO₂) in grams = 12 + 2 × 16 = 44 g = one mole of carbon dioxide
Thus, 22 g of carbon dioxide = (1/44) × 22 = 0.5 moles