431.

Positive deviation from ideal behaviour takes place because of

• molecular interaction between atom and $\frac{\mathrm{PV}}{\mathrm{nRT}}>1$

• molecular interaction between atom and $\frac{\mathrm{PV}}{\mathrm{nRT}}<1$

• finite size of atoms and $\frac{\mathrm{PV}}{\mathrm{nRT}}>1$

• finite size of atoms and $\frac{\mathrm{PV}}{\mathrm{nRT}}<1$

The vapour pressure will be lowest for :

• 0.1 M sugar solution

• 0.1 M KCl solution

• 0.1 M Cu(NO₃)₂ solution

• 0.1 M AgNO₃ solution

A gas at 350 K and 15 bar has molar volume 20 percent smaller than that for an ideal gas under the same conditions. The correct option about the gas and its compressibility factor (Z) is :

• Z > 1 and repulsive forces are dominant

• Z < 1 and attractive forces are dominant

• Z < 1 and repulsive forces are dominant

• Z > 1 and attractive forces are dominant