In a dilute nitric acid solution, copper reacts to form copper nitrate, nitrogen monoxide, and water according to the following equation:

3 Cu(s) + 8 HNO₃(aq) → 3 Cu(NO₃)₂(aq) + 2 NO(g) + 4 H₂O(l)

In a vessel, 800.0 mL of 0.500 M HNO₃ is added to 3.177 g of copper, and the vessel is then sealed. After an hour, the vessel is opened and drained, and the remaining copper rinsed, dried, and weighed. The remaining mass of the copper was 0.0739 g.

(a) Calculate the extent of the reaction.

(b) Calculate the moles of NO generated by the reaction and the moles of HNO₃ remaining.