Based off the information found in the http://h10032.www1.hp.com/ctg/Manual/c04513798, page 11/148, the maximum ram supported with only one DIMM slot available is DDR3L 8GB rated at 1600MHz to run at 1.35v.
You should make sure your BIOS is up to date prior to moving to your new stick of ram to rid your unit of any compatibility issues.
Based off the information found in the http://h10032.www1.hp.com/ctg/Manual/c04513798, page 11/148, the maximum ram supported with only one DIMM slot available is DDR3L 8GB rated at 1600MHz to run at 1.35v.
You should make sure your BIOS is up to date prior to moving to your new stick of ram to rid your unit of any compatibility issues.