Question

you have to make a buffer at pH= 5.00. From the buffer system you chose above (Acetic acid, Pka 4.76). For the correct buffer capacity, the concentration of the weak acid must be 0.100M. How many grams of the sodium conjugate base salt do you need to weigh out and add to the 750ml to make the pH 5.0 exactly

Answer 1

Let x grams of the sodium conjugate base salt do you need to weigh out and add to the 750ml. The molar mass of sodium conjugate base salt (sodium acetate) is 82 g/mol.The mass is divided with molar mass to obtain number of moles. The number of moles of sodium acetate moles.

The volume of sodium acetate is 750 mL or 0.750 L ( 1 L = 1000 mL).

The number of moles of sodium acetate are divided with volume (in L) to obtain molar concentration.

M

g

Hence, 10.7 grams of the sodium conjugate base salt do you need to weigh out and add to the 750ml.