Can you even find 16GB DDR3 modules? IIRC there was only one company which made them and it took a considerable effort due to nobody manufacturing truly suitable dice or lack of addressing bits in the DDR3 standard or something like that, I don't remember.
8GB are common and they may work. I have a motherboard which was never specified to take 8GB modules but it does.
Either way, these are most boring consumer DDR3 modules, no ECC rubbish. Three slots almost surely implies a triple-channel Intel platform as others said. Get three identical modules and it should be good.