Which of the following reactions would have the highest value of work done by the reaction on the surroundings? a) 2 KCIO3(s) - 2 KCI(s)+3 O2(g) BaSO4(s) b) BaO(s)+ SO3(g) 1 c) 2 NO(g) + O2(g) 2 NO2(g) d) 2 H2O2(1) - 2 H2O) + O2(g) e) H2(g) + Cl2(g) 2 HCI

Nitrogen gas (2.75 L) is confined in a cylinder under constant atmospheric pressure (1.01 105 pascals). The volume of gas decreases to 2.10 L when 485 J of energy is transferred as heat to the surroundings. What is the change in internal energy of the gas?

2. In which of the following reactions is there a significant transfer of energy as work from the system to the surroundings? This occurs if there is a change in the number of moles of gases. C(s) + O2(g) → CO2(g) CH4(g) + 2 O2(g) → CO2g) + 2 H2O(g) 2 C(s) + O2(g) → 2 CO(g) 2 Mg(s) + O2(g) → 2 MgO(s)

Dry ice is solid carbon dioxide; it vaporizes at room temperature and normal pressures to the gas. Suppose you put 21.5 g of dry ice in a vessel fitted with a piston (similar to the one in Figure 6.9 but with the weight replaced by the atmosphere), and it vaporizes completely to the gas, pushing the piston upward until its pressure and temperature equal those of the surrounding atmosphere at 24.0C and 751 mmHg. Calculate the work done by the gas in expanding against the atmosphere. Neglect the volume of the solid carbon dioxide, which is very small in comparison to the volume of the gas phase.