When 56.8 g of lead reacts with 3.50 L of oxygen gas, measured at 1.00 atm and 25.0°C, 60.1 kJ of heat is released at constant pressure. What is ΔH for this reaction? (R = 0.0821 L � atm/(K � mol))
a. -3.23 kJ/mol
b. -2.18 kJ/mol
c. -1.61 kJ/mol
d. -0.89 kJ/mol
