Explanation: From the periodic table, we can find that: atomic mass of oxygen = 16 grams atomic mass of phosphorus = 30.97 grams
The balanced equation is: 4P + 5O₂ ..............> 2P₂O₅
From this balanced equation we can note that: 4 moles of P are required to react with 5 moles of O₂ This means that: 4 * 30.97 = 123.88 grams are required to react with 5 * (16*2) = 160 grams
Therefore, to know the mass of oxygen required to react with 62 grams of phosphorus, all we have to do is cross multiplication as follows: 123.88 grams of phosphorus ..................> 160 grams of oxygen 62 grams of phosphorus .........................> ?? grams of oxygen
mass of oxygen = (62*160) / (123.88) = 80.077 grams
