Copper (6.35 g) is dissolved completely in excess dilute nitric acid, which is reduced to NO. Use the balanced ionic equation to find the volume of NO released at STP. Atomic mass Cu = 63.5; molar volume at STP = 22.4 L/mol. Give the answer in litres to two decimal places.

Numerical answer type, answer in L, tolerance 0.02.

Answer: 1.49 L

Balanced equation:

3 Cu + 8 H X^{+} + 2 NO X_{3} X^{-} 3 Cu X^{2 +} + 2 NO + 4 H X_{2} O

. Moles of Cu = 6.35/63.5 = 0.10 mol, and 3 mol Cu give 2 mol NO, so n(NO) = 0.10 x 2/3 = 0.0667 mol. Volume = 0.0667 x 22.4 = 1.49 L.