The standard enthalpies of formation, at 25.00 oC, of methane (CH4(g)), water (H2O(l)), and carbon dioxide (CO2(g)) are, respectively, -74.6 kJ/mol, -285.8 kJ/mol, and -393.5 kJ/mol. Calculate the amount of heat released (in kJ) during the combustion of 17.95 L of methane under a constant pressure of 1.000 atm at 25.00 oC (N.B. combustion is the reaction with molecular oxygen to produce water and carbon dioxide.)
We place a metal rod weighing 5.00 g with a specific heat capacity of 0.302 J/K/g in 22.9 mL of water. The specific heat capacity of water is 4.184 J/K/g and we make the approximation that its density is exactly 1.000 g/mL. The water has an initial temperature of 20.0 oC and the metal rod has an initial temperature of 83.4 oC. What is the final temperature (in oC) of the water and metal rod?
The standard enthalpies of formation, at 25.00 oC, of methanol (CH4O(l)), water (H2O(l)), and carbon dioxide (CO2(g)) are, respectively, -238.7 kJ/mol, -285.8 kJ/mol, and -393.5 kJ/mol. Calculate the change in the entropy of the surroundings (in J/K) upon the combustion of 15.1 g of methanol under a constant pressure of 1.000 atm and a temperature of 25.00 oC. N.B. combustion is the reaction of this substance with molecular oxygen to produce water and carbon dioxide.