Question

For a gas, `"R"/"C"_"v"=0.4`, where R Is universal gas constant and C_v is the molar specific heat at constant volume. The gas is made up of molecules, which are ______

Options

• polyatomic

• rigid diatomic

• monoatomic

• non-rigid diatomic

Answer 1

For a gas, `"R"/"C"_"v"=0.4`, where R Is universal gas constant and C_v is the molar specific heat at constant volume. The gas is made up of molecules, which are rigid diatomic.

Explanation:

As, we know, C_{p =} C_v + R

⇒ `"C"_"p"/"C"_"v" = 1 + "R"/"C"_"v"`

Here, `"R"/"C"_"v"=0.4` and also, `"C"_"p"/"C"_"v"=1+2/"f"`

⇒ `1+2/"f"=1+0.4`

or  `2/"f"=0.4`

or  `"f"=2/0.4=5`

As, degree of freedom is 5, so the gas is made up of molecules which are rigid diatomic (no vibrations).