Is ZOTAC NVIDIA GTX 750TI 2 GB DDR5 Graphics Card compatible with my cpu

You would normally ask if the motherboard is compatible, since that's what you'll connect your GPU to.

And in your case i actually think the motherboard is too outdated to run a GTX750TI, the GTX750TI uses a PCI-E 3.0 bus to connect to your motherboard, allthough PCI-E 3.0 is also backwards compatible to motherboards with PCI-E 2.0.

Now there where a lot of different chipsets for your CPU, but i think it should be PCI-E 2.0, though you should find a spec sheet on your motherboard if possible and check it yourself to make sure.

So if it's PCI-E 2.0 it WILL work, though a dual core with 2GB of RAM is defently a bottleneck for that GPU (bottleneck=they're slowing it down), so i would do a bigger upgrade if i where you, since the GPU aren't going to help more than to the CPU's limits in games, which you'll reach pretty darn fast with 2GB of RAM and a Dual-core scoring 1.700-ish on cpubenchmark.net (a low-budget AMD cpu would score over 4.500 and be quad-core, have PCI-E 2.0 for sure, im talking about the AMD Athlon X4 760K).

So for only a GPU upgrade, don't buy the GTX750TI, GTX750 will probably be as fast with this setup, maybe even a GT740 but i don't think you should go for that one. So get the GTX750 instead.

for full upgrade you can get the AMD Athlon X4 760K, 8GB of DDR3 1600mhz RAM, suitable AMD FM2/FM2+ motherboard and probably a new power supply.

Here's an example on a full upgrade and what it would cost:

PCPartPicker part list: http://pcpartpicker.com/p/K7qM4D

CPU: AMD Athlon X4 760K 3.8GHz Quad-Core Processor ($84.73 @ OutletPC)
Motherboard: MSI A55M-E33 Micro ATX FM2+ Motherboard ($44.99 @ Micro Center)
Memory: Kingston Black 8GB (2 x 4GB) DDR3-1600 Memory ($74.99 @ Amazon)
Video Card: Zotac GeForce GTX 750 Ti 2GB Video Card ($134.99 @ Amazon)
Power Supply: XFX 550W 80+ Bronze Certified ATX Power Supply ($50.99 @ TigerDirect)
Total: $390.69

CPU is way faster (cpubenchmark scores ~1.700 vs ~4.500).
Motherboard is M-ATX size, so should fit most cases, though you should check your case first.
Memory/RAM is DDR3 1600mhz, but most importantly, compared to your current (2GB vs 8GB).
Your desired video card, though if you change PSU like you'll need to here, i would much rather recommend the AMD R9 270, it's faster and around the same price, or the R7 260X.
Power supply i really can't stop recommending this one to people, the 550w version of this series is really cheap, it's a pretty high-end series when it comes to the quality of the PSU, 550w is more than enough.

all this would be just under $400 in the us, around 270% the cost of the GPU.