The core i5 760 specs mention 2 memory channels. Does this mean i can only add max 2 ram chips even if my mobo has more than 2 Ram slots?
No, you can have up to four memory modules with an i5. Each memory channel can handle up to two memory modules, which is true for all other non-server motherboards as well. LGA1156 Core i3s/i5s/i7s as well as AMD AM3 units have two memory controllers, so they can handle up to four memory modules. LGA1366 Core i7s have three-channel memory controllers, which is why they can handle six memory modules per CPU. You will never
see a motherboard with more RAM slots than the CPU can support, since RAM slots cost money and board makers aren't going to waste money by putting in extra useless RAM slots.