a sample consisting of 2.00 mol He is expanded isothermally at 0 C from 5.0 dm^3 to 20 dm^3 reversibly, against a constant external pressure equal to the final pressure of the gas, and freely. calculate q, w, and U

Consider the reduction reactions and their equilibrium constants. cu+(aq)+e−↽−−⇀cu(s)pb2+(aq)+2e−↽−−⇀ pb(s)fe3+(aq)+3e−↽−−⇀fe(=6.2×108=4. 0×10−5=9.3×10−3 cu + ( aq ) + e − ↽ − − ⇀ cu ( s ) k =6.2× 10 8 pb 2 + ( aq ) +2 e − ↽ − − ⇀ pb ( s ) k =4.0× 10 − 5 fe 3 + ( aq ) +3 e − ↽ − − ⇀ fe ( s ) k =9.3× 10 − 3 arrange these ions from strongest to weakest oxidizing agent.