Question

Given that the relative molecular mass of copper oxide is 80, what volume of ammonia (measured at STP) is required to completely reduce 120g of copper oxide? The equation for the reaction is :
3CuO + 2NH₃ → 3Cu + 3H₂O + N₂

Answer 1

3CuO + 2NH₃ → 3Cu + 3H₂O + N₂
Molecular mass of CuO = 80
Volume occupied by 1 mole of NH3 = 22.4L
From the equation :
3 moles of CuO is reduced by 2 moles of ammonia
For 240g of CuO, volume of NH₃ consumed = 44.8L
For 120g of CuO, volume of NH₃ consumed
= 44.8 x 120 / 240 = 22.4 L