Please check the value of cv for triatomic gas i think it should be 9 /2 r... ional degrees or iree- om cach of which contrnbutes energy -r

aluy ncaku tha e temperature, contnibution by vibrational motion is negligible but it has two rotational degrees or Iree- om cach of which contrnbutes energy -RT, Hence, total internal energy (U) =3xRT +2xRT =5RT and - CC+R-R+R =R Hence- 1-49 Similarly for triatomic gas, C = 5R and C, =5R (9/2) R- 130 (7/2) R The values of C C C- C, and y for a few gases at 15°C are listed in Table 1.1. TABLE 1.1. Heat capacities of some gases at 15°C (in cal degree mor Gas Ar 500 3-01 1-99 166 He 4-99 3-00 1-99 166 cO 6-94 4-95 1-99 1-40 H2 6-83 484 1-99 1-41 O 6-96 4-97 1-99 1-40 CO &75 671 2:04 1-30 HS 863 6-54 2-09 1-32 SO 971 7-53 2-18 1-29 CH 9-97 7-91 2-06 1-26 CH 10-07 8-01 2-06 1-26 CH l160 951 2-09 1-22 1.13. 30ULES LAW Thic law deals with the study of variation of internal cnciBy OLd gas with volume at constant temnernts.