"how would you make 100 ml of a carbonic acid buffer at 0.5 m and ph = 6.0 using 1.0 m nahco3 and either 1.0 m naoh or 1.0 m hcl and water? "

You first  start by weighing a quatity of NaHCO3 which is by calculating the molecular mass of the salt and then multiply it with the molarity given which is 0.5 M, the gram/mol gotten is then 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.

Explanation:

molar mass of Na HCO3= 84.01

molarity given= 0.5 M

to get the g/mol to dissolve in 1000 mL , 0.5 x 84.01 =42.005 g/mol=1 L

to get 100 mL , 42.002 divide by 10

=4.2005g/mol