The mole ratio of NO produced to HNO3 reacted is

2:3

2:3

1:4

4:1

3Cu+8HNO3=3Cu (NO3) 2+2NO+4H2O

1:4.

Explanation:

According to the balanced equation,

3Cu + 8HNO₃ → 3Cu (NO₃) ₂ + 2NO + 4H₂O,

It is clear that every 3.0 moles of Cu reacts with 8.0 moles of HNO₃ to produce 3.0 moles of Cu (NO₃) ₂, 2.0 moles of NO and 4.0 moles of H₂O.

∴ The ratio of NO produced to HNO₃ reacted is 2:8 which is 1:4.