Use enthalpies of formation from the textbook to calculate the standard enthalpy of the reaction for the following methane- generating reaction of methanogenic bacteria given delta Hf of CH3NH2=-22.97kJ/mol:
4CH2NH2+2H2O----->3CH4+CO2+4NH3
DHrxn = (n*DHfproducts)-(n*DHfreactants)
To calculate the standard enthalpy of the reaction, you need to use the enthalpy of formation values for the reactants and products involved. The enthalpy of formation (ΔHf) is the change in enthalpy when one mole of a compound is formed from its constituent elements in their standard states.
First, let's determine the enthalpy change for the reaction by subtracting the sum of the enthalpies of formation of the reactants from the sum of the enthalpies of formation of the products. The stoichiometric coefficients in the balanced equation will also be considered:
ΔH = (3 × ΔHf(CH4)) + (ΔHf(CO2)) + (4 × ΔHf(NH3)) - (4 × ΔHf(CH2NH2)) - (2 × ΔHf(H2O))
Now, we can substitute the given values into the equation:
ΔH = (3 × ΔHf(CH4)) + ΔHf(CO2) + (4 × ΔHf(NH3)) - (4 × ΔHf(CH2NH2)) - (2 × ΔHf(H2O))
Considering that ΔHf(CH3NH2) = -22.97 kJ/mol, we need to determine the enthalpies of formation for the remaining compounds. These values can be found in the textbook or reference materials:
ΔHf(CH4) = ? (to be determined)
ΔHf(CO2) = ? (to be determined)
ΔHf(NH3) = ? (to be determined)
ΔHf(CH2NH2) = ? (to be determined)
ΔHf(H2O) = ? (to be determined)
Once you have the relevant enthalpies of formation for these compounds, substitute the values into the equation and perform the necessary calculations to determine the standard enthalpy of the reaction.