Snow Leopard does not run on the G5 processor, it requires an Intel processor.
The highest you can go with the G5 is 10.5.x
did you "borrow" Snow Leopard from the uni or did you buy it?
If purchased, try to get your money back.
right then, i've recently been given a G5 powerpc with 10.4.1 on it from a local university and aiming to install snow leopard onto it, will i run into any immediate problems? also as i got it from the university i don't know the authentication number, will it be impossible to install the software without this? sorry if these questions seem really obvious but i am a complete beginner with mac software.. input would be really appreciated