Calculate the enthalpy change for the combustion of methane gas (CH4) if 37.0 g of CH4 is completely burned in a bomb calorimeter and the temperature increases by 285.4 K. Assume that the calorimeter has a heat capacity of 4.40 kJ/K and that the combustion reaction is as follows: CH4(g) + 2O2(g) -> CO2(g) + 2H2O(l); ΔH=-890.4 kJ/mol. What is the enthalpy change for the combustion of one mole of methane gas?

Question

Calculate the enthalpy change for the combustion of methane gas (CH4) if 37.0 g of CH4 is completely burned in a bomb calorimeter and the temperature increases by 285.4 K. Assume that the calorimeter has a heat capacity of 4.40 kJ/K and that the combustion reaction is as follows: CH4(g) + 2O2(g) -> CO2(g) + 2H2O(l); ΔH=-890.4 kJ

Answer 1

To calculate the enthalpy change for the combustion of 37.0 g of methane gas, we first need to determine the amount of heat released during the reaction. We can do this using the heat capacity of the calorimeter and the temperature change:q = C * Tq = 4.40 kJ/K * 285.4 Kq = 1255.76 kJNow, we need to determine the number of moles of methane gas in 37.0 g:Molar mass of CH4 = 12.01 g/mol  C  + 4 * 1.01 g/mol  H  = 16.05 g/molNumber of moles = mass / molar massNumber of moles = 37.0 g / 16.05 g/molNumber of moles = 2.305 molesNow, we can calculate the enthalpy change per mole of methane gas:H = q / number of molesH = 1255.76 kJ / 2.305 molesH = 544.63 kJ/molHowever, the given enthalpy change for the combustion of one mole of methane gas is -890.4 kJ/mol. The difference between the calculated value and the given value could be due to experimental errors or inaccuracies in the heat capacity of the calorimeter. The enthalpy change for the combustion of one mole of methane gas is -890.4 kJ/mol, as given in the problem statement.