1. Calculate the work involved in expanding 20.0 L of an ideal gas to a final volume of 85.0 L against a constant external pressure of 2.50 bar. (10%)

6. One example of a first-order reaction is the isomerization of hydrogen isocyanide to hydrogen cyanide: . If the rate constant at a particular temperature is , what mass of HCN remains after 1.50 hr if a 1.000-gram sample of HNC was present at the beginning of the reaction? (10%)