Positive deviation from raoult's law occurs when the vapour pressure of component is greater than what is expected in raoult's law. for example, consider two components a and b to form non-ideal solutions. let the vapour pressure, pure vapour pressure and mole fraction of component a be pa, pao and xa respectively and that of component b be ps, pb° and xb respectively. these liquids will show positive deviation when raoult's law when: a. pia]> p[ao] times x[a] and pib] > pibo] times xib], as the total vapour pressure (piao] xia] + p[b0] x[b]) is greater than what it should be according to raoult's law. o b. the solute-solvent forces of attraction is weaker than solute-solute and solvent-solvent interaction o c. the enthalpy of mixing is positive because weaker binding forces or even repulsion are resulted o d. the volume of mixing is positive as weaker binding forces have led to an expansion in volume o a and b only o a, b and c only o all of the above