What was the purpose of adding distilled water to the vinegar solution before titration?

Atrain travels 74 kilometers in 3 hours, and then 81 kilometers in 5 hours. what is its average speed?

Astudent is trying to create a table that compares hypotheses, theories, and laws. hypothesis theory law do scientific researchers formulate it? yes yes yes does it explain why things happen? yes yes no yes yes yes is it used to make predictions? no yes yes which of the following questions would most likely fill the blank in the table? is it an intelligent guess? is it newly formulated? is it based on observations? has it been proved?

Find the mass, in grams, of 5.00*10^23 molecules of f2