Answer is: 48 hydrogen atoms.
One molecul of glycerol(C₃H₈O₃) has eight hydrogen atoms.
One molecul of fatty acid(C₁₆H₂₂O₂) has twenty-two hydrogen atoms, so two same fatty acid will have forty-four hydrogen atoms.
When one fatty acids combine with glycerol via dehydration synthesis er molecul of water is lost, two fatty acids = 2 molecul of water.
Two molecul of water(H₂O) = four hydrogen atoms.
8 + 2·22 - 4 = 48.
