What is the mass of 2 moles of glyceraldehyde (C₃H₆O₃)?

180 grams

The approximate molecular mass of glyceraldehyde can be determined by adding the atomic masses of the constituents (3 carbons atoms plus 6 hydrogen atoms plus 3 oxgen atom) to get of 90 grams / mole {(3 x 12) + (6 x 1) + (3 x 16)]. Therefore if 1 mole of glyceraldehyde has a mass of approximately 90 grams, then 2 moles of glyceraldehyde has a mass of 180 grams.