You can compare the features of both processors at:
However, please keep in mind that you need to contact ACER* and ask them if the Intel® Core™ 2 Quad processor Q6600 is supported by your ACER* system.
Remember that the compatibility is determined by the system manufacturer, but not by the processor manufacturer.
T5500 is a socket M mobile processor, and Q6600 is a socket 775 desktop processor. They are not compatible.