Define the Nernst Heat Theorem
admin The Nernst Heat Theorem Let us consider the Gibbs-Helmholtz equation which includes chemical reaction i.e.: ∆G – ∆H = T (∂ (∆G)/∂T) P ………………………………….. (1) Where ∆G ——-> change in…
April 2025
Determine the Absolute Entropies of Solids
Absolute entropies of solids: Entropy change for an infinitesimally small change of a state of a substance is given as: dS = dq / T If the changes take place…
Derive the Entropy of Real Gases
Entropy of real gases: We know that: (∂S / ∂P)T = – (∂V / ∂T)P ……………………. (1) is one of the Maxwell relations which can also be written as: dS…
Define Carnot Theorem and also give its proof.
Carnot theorem states that no heat engine working in a cycle between two constant temperature reservoirs can be more efficient than a reversible engine working between the same reservoirs. In…
Calculate the maximum efficiency of an engine operating between 120o C and 35o C
Maximum efficiency of an engine working between temperatures T2 and T1 is given by the fraction of the heat absorbed by an engine which can be converted into work is…
A Carnot engine converts one sixth of the heat input into work. If the sink temperature is reduced by 62o C, the efficiency gets doubled. Find the source and the sink temperature.
Maximum efficiency of an engine working between temperatures T2 and T1 is given by the fraction of the heat absorbed by an engine which can be converted into work is…
Carnot engine working between a source temperature of T2 and sink temperature of T1 has efficiency of 25%. If the sink temperature is reduced by 20o C, the efficiency is increased to 30%. Find the source and the sink temperature.
Maximum efficiency of an engine working between temperatures T2 and T1 is given by the fraction of the heat absorbed by an engine which can be converted into work is…
A Carnot engine converts one fifth of the heat input into work. If the sink temperature is reduced by 80o C, the efficiency gets doubled. Find the source and the sink temperature. Also give the consequences of the Carnot cycle.
Maximum efficiency of an engine working between temperatures T2 and T1 is given by the fraction of the heat absorbed by an engine which can be converted into work is…
An ideal gas is heated from temperature T1 to temperature T2 by keeping its volume constant. The gas is expanded back to its initial temperature according to the law PVn = constant. If the entropy changes in the two processes are equal, find the value of n in terms of the adiabatic index γ
Change in entropy during constant volume process is given as: = m cv ln (T2 / T1) Change in entropy during polytropic process i.e. (PVn = constant) = m cv…
A Carnot engine has the same efficiency (i) between 100 K and 500 K and (ii) between T K and 900 K. Calculate the temperature T of the sink.
Maximum efficiency of an engine working between temperatures T2 and T1 is given by the fraction of the heat absorbed by an engine which can be converted into work is…