Answer:
5.76 J/K
Step-by-step explanation:
Mole fraction of Ne at 500 K= 50 % = 0.5 =
![x_A](https://img.qammunity.org/2020/formulas/chemistry/middle-school/1tc966ucy12fiaaih8gey2byctibfv8srr.png)
Mole fraction of Ar at 500 K = 50 %= 0.5 =
![x_B](https://img.qammunity.org/2020/formulas/physics/college/ef2hlmptts88bfvsi36yur47qv1eicel1a.png)
R = Gas constant = 8.314 J/Kmol
As mass is not given the number of moles of Ne and Ar are taken as 0.5
Entropy of mixture
![\Delta_(mix)S=-R(n_Alnx_A+n_Blnx_B)\\\Rightarrow \Delta_(mix)S=-8.314(0.5ln0.5+0.5ln0.5)\\\Rightarrow \Delta_(mix)S=5.76\ J/K](https://img.qammunity.org/2020/formulas/physics/college/2tu4vulfzdv9jc0b2j2u4yekre2xkdkjs5.png)
∴ Entropy of mixture is 5.76 J/K