A) In an experiment, a student needed to use a 0.25 M NaOH solution as standard solution. He prepared 250 mL of the working solution from a stock solution labeled as 50% NaOH. Despite knowing the concentration of the stock and working solutions, the student still needs to standardize the working solution. Give one property of NaOH that explains why the student is still required to standardize the working solution despite knowing he was preparing 0.25 M NaOH solution from the stock solution. Justify your answer. (2 marks)

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?

If two objects at different te,peraure are in contact with each other what happens to their temperature

The rate constant for the reaction below is 6.2 x 10−5 mol l−1 s −1. if the initial concentration of a is 0.0500 m, what is its concentration after 115 s?