4. at what point was the solution in beaker ""b"" neutralized?

Explanation:

This is called the equivalence point. That is the exact point during titration where the relative amounts of each substance in the chemical reaction of titration become well defined by the coefficients in the balanced chemical equation used for expressing the kinetics of reaction.  

A titration is an experimental set up   with a controlled acid-base neutralization reaction.it is used to determine the unknown concentration of an acid or a base.  

Acids and bases neutralize each other, forming a salt and water. Basically, a strong acid-strong base neutralization gives  a neutral solution with a pH of 7.

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.