How did modern scientists experiment with Van Gogh's paints to determine their chemical reactions?

10-14. (a) when 100.0 ml of weak acid ha were titrated with 0.093 81 m naoh, 27.63 ml were required to reach the equivalence point. find the molarity of ha. (b) what is the formal concentration of a- at the equivalence point? (c) the ph at the equivalence point was 10.99. find pk. for ha. (d) what was the ph when only 19.47 ml of naoh had been added?

An observation that requires measurement is called quantitative observable or qualitative

How many mmols of tris-hcl are there in 100 ml of a 100 mm tris-hcl buffer solution at ph 8.1? note that the 100 mm refers to the sum of tris and tris-hcl concentrations?