About 203 1.5-teaspoon measures per 1.5 liters.
There are approximately 500 teaspoons in 2.5 liters.
3.5 US teaspoons = 0.052 liters.
0.592L = 40.04 US teaspoons.
400 mL = 81.15 US teaspoons.
80 mL = 16.23 US teaspoons.
That is 761.918 teaspoons
15 teaspoons is about 74 mL
Multiply liters by 202.9 to get teaspoons. (0.1 x 202.9 = 20.29 teaspoons).
About 15 teaspoons
That is 1.5 teaspoons.
7.5 cc of water in 1.5 teaspoons.
That is 3 teaspoons of water.