EDTA is a hexaprotic system with the pKa values: pKa1=0.00 , pKa2=1.50 , pKa3=2.00 , pKa4=2.69 , pKa5=6.13 , and pKa6=10.37 . The distribution of the various protonated forms of EDTA will therefore vary with pH. For equilibrium calculations involving metal complexes with EDTA , it is convenient to calculate the fraction of EDTA that is in the completely unprotonated form, Y4− . This fraction is designated Y4− . Calculate Y4− at two pH values.

You mix the pks of succinic acid are 4.21 and 5.64. how many gramsa graduate student at sdsu wants to measure the activity of a particular enzyme at ph 4.0. to buffer her reaction, she will use a buffer system based on one of the acids listed below, which acid is most appropriate for the experiment? of monosodium succinate (fw = 140 g/mol) and disodium succinate (fw = 162 g/mol) must be added to 1 l of water to produce a solution with a ph 5.28 and a total solute concentration of 100 mm? (assume the total volume remains 1 liter, answer in grams monosodium succinate, grams disodium succinate, respectively.) volumes of 0.05 m nah2po4 and 0.05 m na2hpo4 (pk's for phosphoric acid are 2.15, 6.82 and 12.38). which of the following best describes the resulting solution?

Chemical energy is a form of a. kinetic energy only. b. both potential and kinetic energy. c. neither potential nor kinetic energy. d. potential energy only. reset

Calculate the number of kilojoules to warm 125 g of iron from 23.5°c to 78.0°c.