Siannon

Okay so I need a little help with a few questions if someone could explain how to solve these that would be great (: Prepare 500 mL of 0.5 M Na2EDTA(there's a black dot in the middle here)2H2O Weigh out the correct amount of EDTA sodium salt. Show the calculation setup used to determine amount needed. -----How do I do this? Add the EDTA to 400mL of deionized water in a 500mL volumetric flask. Stir with a stir bar on a magnetic stir plate and measure the pH. Add 10 M NaOH drop by drop until the pH is 8. Is the EDTA completely dissolved? ----Is it? We didn't finish this in lab so I don't know how to tell.... And then there's: Preparation of 1.0 M Tris HCI with two different pH values. How did you standardize the pH meter for this preparation? ---Another thing we didn't do in lab, can anyone explain how I would do this? How would you prepare a 7.5 M solution of NH4OAc? Using the 7.5 M solution of NH4OAc and the stock solutions that you prepared yourself show the calculations you would use to prepare 200mL of the solution below: 5M NH4OAc 0.5 M Glucose 50mM Na2EDTA(black dot)2H20 -----is this a c1v1=c2v2 formula? if not what formula is it? If you prepare a 1/40 dilution of 50% solution, what is the final concentration of the solution? ---How do you do this? A stock solution of enzyme contains 10mg/ml of enzyme. 100mL of this stock is diluted with 400 mL of buffer. What is the concentration of the enzyme in the resulting diluted solution? How much enzyme will be present in 300μl of the resulting dilution? Thanks soo much!!!!