Question

11. If equal moles of following gases are taken at
constant temperature and pressure then gas of
highest entropy is

(1) He(g)
(2) H2 (9)
(3) CO2(g)
(4) PCI5(g)
please give reason​

Answer 1

If equal moles of the following gases are taken at  constant temperature and pressure then gas with the  highest entropy is (4) PCI5(g).

• The entropy of a gas depends on various factors like temperature and pressure etc.
• If the physical conditions are the same, the entropy of a gas is directlty proportional to its degree of freedom.
• We know that the degree of freedom for a monoatomic, diatomic, linear polyatomic, and non-linear polyatomic gas is 3, 5, 6, and 7 respectively.
• He is a monoatomic gas.
• H₂ has 2 atoms and is diatomic gas.
• CO₂ and PCl₅ are both polyatomic. CO₂ has a linear structure while PCl₅ has a trigonal bipyramidal shape.

      So the order of entropy is: PCl₅ > CO₂ > H₂ > He

Answer 2

Explanation:

PCl5 because it has more atomicity