A student placed 6.0 grams of baking soda into a small balloon. The mass of the
balloon and soda was measured at 7.0 grams. Next, the student poured a measure of
vinegar into a Florence flask that had an empty mass of 100 grams. After the balloon
was stretched across the top of the flask, the student dumped the soda into the vinegar.
A gas was formed by a chemical reaction that filled the balloon. After the reaction
stopped, the student placed the flask with the filled balloon on a balance scale and it
measured 125 grams.
What was the mass of the vinegar the student put in the flask at the start?