Answer:
7.5 moles
Step-by-step explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
3Cu + 2H3PO4 —> Cu3(PO4)2 + 3H2
From the balanced equation above,
3 moles of Cu reacted with 2 moles of H3PO4.
Therefore, Xmol of Cu will react with 5 moles of H3PO4 i.e
Xmol of Cu = (3 x 5)/2
Xmol of Cu = 7.5 moles
Therefore, 7.5 moles of Cu are needed to react with 5 moles of H3PO4.