Chemistry

6. A student needs to prepare a buffer of pH 3. The chemicals available in the lab are the following:  sodium fluoride, sodium acetate, sodium hydrogen carbonate, sodium carbonate, and sodium benzoate – All of these compounds are available in their solid form.  1 M stock aqueous solutions of: phosphoric acid, sodium hydrogen phosphate, sodium dihydrogen phosphate, acetic acid, benzoic acid, and hydrofluoric acid Describe in detail what you would do in order to prepare 100 mL of this buffer using a volumetric flask. Show calculations if necessary. 7. (a) Calculate the pH of a solution that is 0.50 M acetic acid and 0.91 M sodium acetate. (b) How would you prepare 250.0 mL of this buffer solution if you have a stock solution of 3.0 M acetic acid and another stock solution of 1.5 M sodium acetate? 8. Calculate the mass of ammonium chloride that must be added to 500.0 mL of 0.52 M NH3 to prepare a pH 8.50 buffer. 9. How many milliliters of 0.0860 M NaOH are required to titrate 50.0 mL of 0.0950 M HNO3? Show your calculations.