How to calculate the enthalpy change of water?
Yes, but your answer should be just in joules not $\mathrm{J/g}$, and your units are off. 

$$(2.6~\mathrm{\color{\red}{g}})\left(4.184~\mathrm{\frac{J}{\color{\red}{g}\ K}}\right)(5~\mathrm{K})= 50~\mathrm{J}$$