Most photos we see of Enya are the photos in the album booklets, or photos from magazines. As it is with all artists, Enya wears cosmetics in these photos, and sometimes the photos might be retouched to create a certain look.
Introduction Heat of formation is the enthalpy change when one mole of product is formed from its constituent elements under standard conditions. The equation for the formation of calcium carbonate from its elements under standard conditions is Ca(s)+C (graphite)+O2 (g) CaCO3(s).HfO (CO2 (g)) = -393.5 kJ mol -1 ?HfO (H2O (l)) = -285.5 kJ mol -1 Heat of formation of calcium carbonate = ?H1 + ?Hf (CO2 (g)) +?Hf (H2O (l))- ?H2 = -421+(-393.5)+(-285.5)- (-17.6) = -1082.4 kJ mol -1 In order to achieve the answer, Hess's law is used.
At 850Â°C, CaCO3 undergoes substantial decomposition to yield CaO and CO2. Assuming that the DH0f values of the reactant and products at 850Â°C are the same as those at 25Â°C, calculate the enthalpy change (in kJ) if 50.0 grams of CO2 (molec. wt. = 44.0) is produced in the reaction.t 850Â°C, CaCO3 undergoes substantial decomposition to yield CaO and CO2. Assuming that the DH0f values of the reactant and products at 850Â°C are the same as those at 25Â°C, calculate the enthalpy change (in kJ) if 50.0 grams of CO2 (molec. wt. = 44.0) is produced in the reaction.