Question

An unknown sample of an organic substance weighing 3.6g contains 0.05 mole burns in excess one and produces 11g co2 and 5.4g h2o calculate the standard enthalpy of formation of the organic substance, if from burning 3.6 g of it with excess oxygen releases 177kj and delta h^0 f (h2o) = -286 kj/mol, delta h° (co2)= -391 kj/mol,

Answer 1

To calculate the standard enthalpy of formation of the organic substance, you need to calculate the moles of CO2 and H2O produced, the heat released per mole of the organic substance, and then use the enthalpies of formation for CO2 and H2O to calculate the overall enthalpy change.

Step-by-step explanation:

To calculate the standard enthalpy of formation of the organic substance, we need to use the enthalpy change for the combustion reaction and the enthalpies of formation for CO2 and H2O. First, calculate the moles of CO2 and H2O produced:

1. Convert the mass of CO2 and H2O produced to moles by dividing by their respective molar masses.
2. Using the mole ratio from the balanced equation, calculate the moles of the organic substance.

Next, calculate the heat released in kJ per mole of the organic substance:

1. Divide the heat released by the moles of the organic substance to get the heat released per mole.

Finally, calculate the standard enthalpy of formation:

1. Write the balanced equation for the combustion of the organic substance.
2. Use the enthalpies of formation for CO2 and H2O to calculate the overall enthalpy change.
3. Subtract the overall enthalpy change from the enthalpies of formation of CO2 and H2O to find the enthalpy of formation for the organic substance.