Question

Calculate the pH of a solution prepared by dissolving 2.05g of sodium acetate, CH3COONa, in 57.0 ml of 0.10 M acetic, CH3COOH(aq) . Assume the volume change upon dissolving the sodium acetate is negligible. Ka of CH3COOH is 1.75 x10-5

Answer 1

The first step is to find the concentration of acetate in the solution, to do it, convert the given mass to moles using sodium acetate molar mass:

`2.05gCH_3COONa\cdot(1molCH_3COONa)/(82.0343gCH_3COONa)=0.025molCH_3COONa`

Now, divide the amount of moles by the volume in liters:

`(0.025molCH_3COONa)/(0.057L)=0.44M`

Finally use the equation of Henderson-Hasselbach to calculate the pH