ThermodynamicsHard
Question
The difference between heats of reaction at constant pressure and constant volume for the reaction
2C6H6(l) + 1502(g) → 12CO2(g) + 6H2 O(l) at 25oC in kJ is :
2C6H6(l) + 1502(g) → 12CO2(g) + 6H2 O(l) at 25oC in kJ is :
Options
A.- 7.43
B.+3.72
C.- 3.72
D.+7.43
Solution
Heat of reaction at constant pressure = ᐃH and at
constant volume = ᐃH
But ᐃH = ᐃU + ᐃnRT
Fro the reaction
2C6H6(l) + 15O2(g) → 12CO2(g) + 6h2O(l)
ᐃn = 12 - 15 = - 3 (Count gasecos molecules only)
and ᐃH - ᐃU = ᐃnRT
= - 3 × 8.314 × (273 + 25)
= - 74327 J ⇒ - 7.43KJ
constant volume = ᐃH
But ᐃH = ᐃU + ᐃnRT
Fro the reaction
2C6H6(l) + 15O2(g) → 12CO2(g) + 6h2O(l)
ᐃn = 12 - 15 = - 3 (Count gasecos molecules only)
and ᐃH - ᐃU = ᐃnRT
= - 3 × 8.314 × (273 + 25)
= - 74327 J ⇒ - 7.43KJ
Create a free account to view solution
View Solution FreeMore Thermodynamics Questions
Five moles of an ideal gas is expanded isothermally from 5 dm3 to 5 m3 at 300 K. Which of the following is incorrect abo...What is the change in internal energy when a gas contracts from 325 ml to 125 ml at a constant pressure of 2 bar, while ...Two moles of an ideal gas [Cv,m (/JK−1 mol−1) = 20 + 0.01T(/K)] is heated at constant pressure from 27°C to 127°C. The a...At very low temperature, the heat capacity of crystals is equal to C = aT3, where a is a constant. Find the entropy of a...A piston can freely move inside a horizontal cylinder closed from both ends. Initially, the piston separates the inside ...