I've seen a question just like this but the 9.50L was 10 and the 23.0L was 20.0 and the answer was 328mmhg idk if they could be different or something.
Answer: water has a high surface tension because the water molecules on the surface are pulled together by strong hydrogen bonds. That means a drop of water will ´´want´´ to have the smallest possible surface area. The shape that has the smallest possible area for a given area is a sphere.
Explanation:hope this helps!