I'm doing a project and have one small problem. My project calls for two 2.2uF capacitors, I only have one. I have plenty of 1uF capacitors, three 10uF capacitors and two 100uF caps. Can I use three 1uF caps in series or can I use one of the 10uF caps instead?
It depends on project. As long as the ESR, voltage rating, etc are comparable then it is probably ok. In some instances parallel capacitors results in lower ESR that may help you (lower ESR ripple at the output of a switching regulator), or hurt you (some LDOs will go unstable).