Will my motherboard support 2x16GB of RAM?

Yes, unless you’re on a very old platform or a weird OEM board. Most modern motherboards support 2x16GB without issue. The real concern is whether it’ll run at your desired speed, so check the motherboard’s Qualified Vendor List (QVL) for 2x16GB kits, but that list isn’t exhaustive. The days of needing 4x8GB due to per-slot limits are mostly over with DDR4 and DDR5, except for some older chipsets like Intel H310 from 2012.