Advertisements
Advertisements
Question
How will you calculate work done on an ideal gas in a compression, when change in pressure is carried out in infinite steps?
Solution
When a process can be reversed by bringing an extremely small change in it, we call it a reversible process. The pressure-volume graph can be used to calculate the work done. The pressure is not constant, and changes in infinitesimal amounts as compression happens from initial volume Vi to the final volume Vf. The below graph depicts the work done with the shaded area.
APPEARS IN
RELATED QUESTIONS
A sample of 1.0 mol of a monoatomic ideal gas is taken through a cyclic process of expansion and compression as shown in figure 6.1. What will be the value of ∆H for the cycle as a whole?
What will be the work done on an ideal gas enclosed in a cylinder, when it is compressed by a constant external pressure, pext in a single step as shown in figure. Explain graphically.
Represent the potential energy/enthalpy change in the following processes graphically.
(a) Throwing a stone from the ground to roof.
(b) \[\ce{1/2 H2(g) + 1/2 Cl2 (g) ⇌ HCl (g) Δ_rH^Θ = - 92.32 kJ mol^{-1}}\]
In which of the processes potential energy/enthalpy change is contributing factor to the spontaneity?
An ideal gas is allowed to expand against a constant pressure of 2 bar from 10 L to 50 L in one step. Calculate the amount of work done by the gas. If the same expansion were carried out reversibly, will the work done be higher or lower than the earlier case? (Given that 1 L bar = 100 J)
Match the following :
| Column I | Column II |
| (i) Entropy of vapourisation | (a) decreases |
| (ii) K for spontaneous process | (b) is always positive |
| (iii) Crystalline solid state | (c) lowest entropy |
| (iv) ∆U in adiabatic expansion of ideal gas | (d) `(∆H_(vap))/T_b` |
For silver Cp (J K-1 mol-1) = 23 + 0.01 T. If the temperature (T) of 3 moles of silver is raised from 300 K to 1000 K at 1 atom pressure, the value of ΔH will be close to ______.
The net work done in the following cycle for one mol of an ideal gas will be ______ (in calorie), where in process BC, PT = constant. (R = 2 cal/mol-K).
1 mole of an ideal monoatomic gas initially at 1 atm and 300 K experiences a process by which pressure is doubled. The nature of the process is unspecified but 6. ΔU = 900 cal. The final volume will be ______ l.
[Given : R = 0.08 atm lit. I mol/K = 2 Cal/K/mol J]
Find the work done when 2 moles of hydrogen expand isothermally from 15 to 50 litres against a constant pressure of 1 atm at 25°C.
An ideal gas expands in volume from 1 × 10−3 to 1 × 10−2 m3 at 300 K against a constant pressure of 1 × 105 Nm−2. The work done is ______.
