It does appear to be a socketed motherboard, so possibly. Typically you want to stick with the TDP of whatever CPU is already in there, otherwise you might overwhelm the cooling and end up with worse performance.
Given the age of it though, unless you can do it very cheaply, you would be better off investing in a new laptop. We are talking about 50% or more performance per core and a near doubling of battery life. Not to mention how much Intel HD graphics and discrete mobile GPUs (Nvidia 10 series) have improved. With Intel 8th generation they upped the core count on most models. So they have i5 that are faster than previous generation i7.