I5 3000 series, i5 4000 series, and i5 5000 series all use DDR3 ram. Only the new i5 6000 series use DDR4. As to your motherboard, if it will take an i3, then you can also fit an i5 in there.
Tell us your motherboard name and model. I5s are different, most use DDR3 and the new Skylake uses DDR4 or DDR3L. ALso tell us what kind of I5 do you have.
I5 3000 series, i5 4000 series, and i5 5000 series all use DDR3 ram. Only the new i5 6000 series use DDR4. As to your motherboard, if it will take an i3, then you can also fit an i5 in there.