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Question
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?
Solution
(a) Throwing a stone from ground to roof
(b) The reaction involved is a process where the energy decreases after the reaction. It can be represented as:
In process (b), potential energy/enthalpy change is a contributing factor to the spontaneity.
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Match the following :
| A | B |
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| (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 |
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| (x) ΔH = q | (j) Infinitely slow process which proceeds through a series of equilibrium states. |
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| (m) Specific heat |
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