hygroscopic properties question

[1ara]

Can someone please explain the difference in hygroscopic properties between petrodiesel and biodiesel please

[Erutepa]

Can someone please explain the difference in hygroscopic properties between petrodiesel and biodiesel please

All I think you would need to know is that biodiesel is more hygroscopic, meaning it will more readily absorb water from its surroundings.
For fuels this is a bad thing as it will increase the rate at which metal parts in an engine, for example, corrodes.
Hope this is satisfactory 

[huity]

Adding onto Erutepa's comprehensive answer, you should definitely talk about bonding when explaining why biodiesel is more hygroscopic. VCAA examiners are looking for this, especially in questions which are more than 1 mark!

Biodiesel's polar ester group can form dipole-dipole interactions with water, whereas petrodiesel's hydrocarbon chain only results in dispersion forces. Thus, biodiesel is more hygroscopic ans likely to absorb water from its surroundings compared to petrodiesel.