Answer:
0.725 mol
Explanation:
Moles are calculated as the given mass divided by the molecular mass.
i.e. ,
moles = ( mass / molecular mass )
since,
mass of KNO₃ = 58.6 g ( given )
Molecular mass of KNO₃ = 101 g / mol
Therefore,
moles of KNO₃ = 58.6 g / 101 g / mol
moles of KNO₃ = 0.58 mol
From the balanced reaction ,
4 KNO₃ (s) ---> 2K₂O (s) + 2N₂ (g) + 5O₂ (g)
By the decomposition of 4 mol of KNO₃ , 5 mol of O₂ are formed ,
hence, unitary method is used as,
1 mol of KNO₃ gives 5 / 4 mol O₂
Therefore,
0.58 mol of KNO₃ , gives , 5 / 4 * 0.58 mol of O₂
Solving,
0.58 mol of KNO₃ , gives , 0.725 mol of O₂
Therefore,
58.6g of KNO₃ gives 0.725 mol of O₂.
