(Answer) 0.166 moles of copper (I) nitride are needed.
Mass of copper (I) oxide = 35.7 g
Moles of copper (I) oxide formed by the reaction = (Mass / molar mass)
= ( 35.7 g / 143.09 g/mol ) = 0.25 moles
According to the balanced chemical equation,
mole ratio of copper (I) nitride and copper (I) oxide = 2: 3
Therefore, moles of copper (I) nitride needed to form 0.25 moles of copper (I) oxide = (2/3 x 0.25) moles = 0.166 moles.
Thus, 0.166 moles of copper (I) nitride are needed to form 0.25 moles of copper (I) oxide.