Question

calculate the change of entropy when 0.14kg of gas initially at 170°C expands with a volume ratio of 5.4 according to pv^1.24=constant. take gamma=1.4 and R=287kj/kgK​

Answer 1

  Entropy is a state function.

The entropy change is determined by its initial and final states only

Answer 2

change of entropy = $1.81*10^-4$

Explanation:

• Entropy change can be defined as the change in the state of disorder of a thermodynamic system that is associated with the conversion of heat or enthalpy into work. A system with a great degree of disorderliness has more entropy.
• The entropy change of a chemical reaction at 298 K is simply the difference between the sum of the standard entropies of the products and the sum of the standard entropies of the reactants.

$m = 0.14kg$

$t=170c$

$pv = 1.24$

gamma = $1.4$

$R=287kj/kgK​$

$pv = mrt$

$m= mass$

$t = temperature$

= $1.24 = 0.14*287*170$

change of entropy = $1.81*10^-4$