Question

If you were to add 10.0mL of 0.10M sodium acetate solution, what is the amount of CH3COOH(mol), Amount of CH3COO-(mol), and the predicted pH by the Henderson-Hasselbalch equation?

Given:

Start with sodium acetate

Add HCl

Initial Burette reading: 6.70ml

Final Burette reading: 9.80mL

Amount of HCl added(mol): 3.1 x 10^-4 mol

Answer 1

firstly the number of moles of sodium acetate is found

number of moles =( molarity * volume in ml ) / 1000

which is found to be 0.001 moles

then themoles of acetic acid formed is found by considering the moles of HCl (by the balanced chemical equation, both are found to be in one is to one equivalence )

therefore , the number of moles of acetic acid formed is 0.00031 moles

and remaining sodium acetate is 0.00069 moles

the pH is found by using henderson-hasselbalch equation

pH = pKa + log( conc. of salt / conc. of acid )