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प्रश्न
The pressure-volume work for an ideal gas can be calculated by using the expression w = `- int_(v_i)^(v_f) p_(ex) dV`. The work can also be calculated from the pV– plot by using the area under the curve within the specified limits. When an ideal gas is compressed (a) reversibly or (b) irreversibly from volume Vi to Vf. choose the correct option.
विकल्प
w (reversible) = w (irreversible)
w (reversible) < w (irreversible)
w (reversible) > w (irreversible)
w (reversible) = w (irreversible) + `P_(ex).∆V`
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उत्तर
w (reversible) < w (irreversible)
Explanation:
Area under the curve is greater in irreversible compression than that of reversible compression.
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संबंधित प्रश्न
For an ideal gas, the work of reversible expansion under isothermal condition can be calculated by using the expression w = `- nRT` In `V_f/V_i`. A sample containing 1.0 mol of an ideal gas is expanded isothermally and reversibly to ten times of its original volume, in two separate experiments. The expansion is carried out at 300 K and at 600 K respectively.
(i) Work done at 600 K is 20 times the work done at 300 K.
(ii) Work done at 300 K is twice the work done at 600 K.
(iii) Work done at 600 K is twice the work done at 300 K.
(iv) ∆U = 0 in both cases.
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(a) Throwing a stone from the ground to roof.
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| A | B |
| (i) Adiabatic process | (a) Heat |
| (ii) Isolated system | (b) At constant volume |
| (iii) Isothermal change | (c) First law of thermodynamics |
| (iv) Path function | (d) No exchange of energy and matter |
| (v) State function | (e) No transfer of heat |
| (vi) ΔU = q | (f) Constant temperature |
| (vii) Law of conservation of energy | (g) Internal energy |
| (viii) Reversible process | (h) Pext = o |
| (ix) Free expansion | (i) At constant pressure |
| (x) ΔH = q | (j) Infinitely slow process which proceeds through a series of equilibrium states. |
| (xi) Intensive property | (k) Entropy |
| (xii) Extensive property | (l) Pressure |
| (m) Specific heat |
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` |
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[Given : R = 0.08 atm lit. I mol/K = 2 Cal/K/mol J]
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