You can probably upgrade to 32GB — but it depends on your soldered RAM.

It depends on how your current 16GB is split between soldered and the open slot. If the soldered part is 16GB (common in some ultrabooks), then adding a 16GB stick in the open slot gives you 32GB total. If the soldered part is 8GB and you have an 8GB stick in the slot, swapping that for a 16GB stick gets you only 24GB — not 32GB.

Check your system info (Task Manager > Memory on Windows, or `system