Will my laptop be able to run Dolphin emulator?

Easily. The system requirements are very low for dolphin emulator.

Dolphin has VERY high cpu requirements. Not many laptops can play games at full speeds.

If your i5 is a full speed one (like able to turbo boost to ~3.0ghz+), then you should be able to play a good number of games well. But you would want an i7 (4th or 5th gen) capable of hitting like 3.6ghz+ to play majority of games at full speed.