Question

How would you make 100 mL of a carbonic acid buffer at 0.2 M and pH = 9.8 using 0.5 M HCO3 and either 0.1 M NaOH or 0.1 M HCl and water?

Answer 1

You want 100 mL of 0.2M so weigh out 0.2 mol NaHCO3, dissolve in some water, add 0.1M NaOH dropwise until the pH is 9.8. Transfer quantitatively to a 100 mL volumetric flask and dilute to the mark. Mix thoroughtly.