1) Number of moles of product, carbon dioxide, is the same as that of vinegar. So the most efficient reaction is the one with the less amount of baking soda. So RXN 1 is the most efficient.
2) Number of moles of product, carbon dioxide, is the same as that of vinegar; except RXN 5. There is an error in the number of moles of carbon dioxide. It should be 0.05034.