Final answer:
a. To calculate the energy released when 48.6 g of CaCO3 decomposes, convert the mass to moles and multiply by the enthalpy change. The energy released is 91.76 kJ. b. To calculate the heat released or absorbed in the reverse reaction to produce 70 g of CaCO, use the stoichiometry of the reaction. The heat released or absorbed is 132.14 kJ.
Step-by-step explanation:
a. Calculation for Energy Released:
To calculate the energy released when 48.6 g of CaCO3 decomposes, we need to convert the mass of CaCO3 to moles using its molar mass. The molar mass of CaCO3 is 100.1 g/mol. Therefore, the number of moles of CaCO3 is: 48.6 g / 100.1 g/mol = 0.4859 mol. Since the enthalpy change for the reaction is given as 188.8 kJ/mol, we can multiply the number of moles by the enthalpy change to calculate the energy released: 0.4859 mol * 188.8 kJ/mol = 91.76 kJ.
b. Calculation for Reverse Reaction:
To calculate the heat released or absorbed in the reverse reaction to produce 70 g of CaCO, we can use the stoichiometry of the reaction. From the balanced equation, we know that 1 mole of CaCO3 produces 1 mole of CaO and 1 mole of CO2. Therefore, we need to calculate the moles of CaCO3 corresponding to 70 g. The molar mass of CaCO3 is 100.1 g/mol, so the number of moles is: 70 g / 100.1 g/mol = 0.699 mol. Since the enthalpy change for the reaction is given as 188.8 kJ/mol, we can multiply the number of moles by the enthalpy change to calculate the heat released or absorbed: 0.699 mol * 188.8 kJ/mol = 132.14 kJ.