Answer:
40 drops
Approximately 0.166 %
Explanation:
It would be easier to work the same units for volume
Since there are 1000 ml in a liter
Original water volume 1.2 L = 1.2 x 1000 = 1200 mLl
The final volume of the acid-water solution = 1.202 L = 1202 mL
So total volume of acid added = 1202-1200 = 2 mL
Each drop of acid is 0.05 mL
Number of drops added = 2/.05 = 40 drops
Percent of acid in acid solution = (Volume of acid added)/(Final volume) x 100 = (2/1202) ≈ 0.00166 x 100 ≈ 0.166 %