what is delta h

Question

Limestone stalactites and stalagmites are formed in caves by the following reaction: A* (aq) + 2HCO3 (aq) → CaCO3(s) + CO2(g) + H20(l) If 1 mol of CaCO forms at 298 K under 1 atm pressure, the reaction performs 2.49 kJ of P - V work, pushing back the atmosphere as the gaseous COz forms. At the same time, 38.95 kJ of heat is absorbed from the environment. what is delta H

Answer 1

The ∆H (q_p or heat @ constant pressure) would simply by the +38.85 kJ. Now, if you meant to ask what is the ∆U (change in internal energy) then, we will also use the work done, as follows:

∆U = q + w

∆U = change in internal energy = ?

q = heat = + 38.95 kJ (positive since heat is being absorbed by the system)

w = work = -2.49 kJ (negative since the system is doing work on the surroundings)

∆U = 39.95 kJ - 2.49 kJ = 37.46 kJ