Calculate H for each of the following processes. In each case, restate your result as a specific

Question:

Calculate ΔĤ for each of the following processes. In each case, restate your result as a specific enthalpy relative to a reference state. [The solution—which you should verify—and the restatement for Part (a) are given as an illustration.] Assume that the process pressures are low enough for Ĥ to be considered independent of pressure, so that the formulas of Table B.2 (which strictly apply at 1 atm) can be used.

(a) CH₃COCH₃(l, 15°C) → CH₃COCH₃(l, 55°C).

Solution: ΔĤ = 5.180 kJ/mol

The specific enthalpy of liquid acetone at 55°C relative to liquid acetone at 15°C is 5.180 kJ/mol.

(b) n-C₆H₁₄(l, 25°C) → n-C₆H₁₄(l, 80°C)

(Make statements about both the specific enthalpy of hexane vapor at 500°C relative to hexane vapor at 0°C and the specific enthalpy of hexane vapor at 0°C relative to hexane vapor at 500°C.)

Table B.2

TABLE B.2 Heat Capacities Form 1: C,[kJ/(mol-C)] or [kJ/(mol·K)] = a + bT + cT + dT Form 2: C,[kJ/(mol-C)] or [kJ/(mol-K)] = a + bT + cT? Example: (C,)acetone(e) = 0.07196 + (20.10 x 10-$)r - (12.78 x 10-8)7? + (34.76 x 10-12)Tr*, where T is in °C. %3D