Which of the following two assumptions of the kinetic molecular theory do not hold good for real gases ?
(i) There is no force of attraction between the molecules of a gas.
(ii) The particles of a gas are always in constant and random motion in all possible directions in straight lines.
(iii) At any particulat time, different particle sin the gas have different speeds and hence, different kinetic energies.
(iv) The volume of the molecules of a gas is negligibly small in comparision to the space occupied by the gas.

Options

A. `(i),(ii),(iii)`
B. `(ii),(iii)`
C. `(i),(iv)`
D. `(i),(ii),(iii),(iv)`

Answer

C

Explanation

If assumption(i) is correct , the gas will never liqefy , i.e., without intermolecular forces , gases cannot condense as `CO_(2)` do liquefy when cooled and compressed. Moreover, liquids formed are very difficult to compress because the forces of repulsion are powerful enough to present the squashing of molecules in tiny volume. If assumption (iv) data (real gas) and that theoretically calculated from Boyle's law (ideal gas) should coincide.