Limestone stalactites and stalagmites are formed in caves by the following reaction:
Ca2+(aq)+2HCO−3(aq)→CaCO3(s)+CO2(g)+H2O(l)
If 1 mol of CaCO3 forms at 298 K under 1 atm pressure, the reaction performs 2.48 kJ of P−V work, pushing back the atmosphere as the gaseous CO2 forms. At the same time, 38.65 kJ of heat is absorbed from the environment.
What is the value of ΔE for this reaction?
