Answer:
I think B would be alcohol but A I'm not to sure
MgCl2
Mg=24
Cl=35.5×2 = 71
rmm= 71+24=95g
1 mole = molar mass
1 mole = 95g
1g = 1/95 moles
345g= 1/95 × 345
3.6 moles
C6H10O5 (6 Carbon, 10 Hydrogen and 5 Oxygen)
Your answer would come out to 18 electrons