Advertisements
Advertisements
Question
Select the most appropriate option.
A gas is allowed to expand in a well-insulated container against a constant external pressure of 2.5 bar from an initial volume of 2.5 L to a final volume of 4.5 L. The change in internal energy, ΔU of the gas will be _______.
Options
–500 J
+ 500 J
–1013 J
+ 1013 J
Solution
- 500 J
Explanation:
Since the container is insulated, this is an adiabatic process.
For adiabatic process,
ΔU = +W = - Pext Δ V = - Pext (V2 - V1)
Initial volume (V1) = 2.5 L = 2.5 dm3
Final volume (V2) = 4.5 L = 4.5 dm3
External pressure (Pext) = 2.5 bar
ΔU = W = - 2.5 bar × (4.5 dm3 - 2.5 dm3)
= - 5.0 dm3 bar × `(100 "J")/(1 "dm"^3 "bar")`
= - 500 J
RELATED QUESTIONS
Select the most appropriate option.
The correct thermodynamic conditions for the spontaneous reaction at all temperatures are _______.
Select the most appropriate option.
6.24 g of ethanol are vaporized by supplying 5.89 kJ of heat. Enthalpy of vaporization of ethanol will be _______.
Select the most appropriate option.
Which of the following are not state functions?
- Q + W
- Q
- W
- H - TS
Select the most appropriate option.
For vaporization of water at 1 bar, ΔH = 40.63 kJ mol–1 and ΔS = 108.8 J K–1 mol–1 . At what temperature, ΔG = 0?
Derive the expression for work done in chemical reaction. Write the relationship between ∆H and ∆U for an isochoric process.
If \[\ce{C(s) + O2(g) -> CO2(g), \Delta H = - \text{x}}\]
\[\ce{CO(g) + \frac{1}{2} O2(g) -> CO2(g), \Delta H = - \text{y}}\],
Calculate Δf H for CO(g) formation.
Thermodynamics deals with ______.
Write the expression for work done in a chemical reaction.
