Dell Inspiron N4050 Processor Upgrade

Hi.

      I have Inspiron N4050 (32-Bit System) with 4 GB RAM, Processor is  Pentium B950 @2.1 GHz. 

I see different posts already but mostly for Celeron B815 1.6Ghz.

Can I please ask which i5 processor I can upgrade to? 

Thanks.