Question

What is the change in pH when 0.005 moles of HCl is added to 0.100 L of a buffer solution that is 0.100 M in CH3CO2H and 0.100 M NaCH₃CO₂? The Ka for acetic acid is 1.80E-5 Enter your answerwith two decimal places and without units.

Answer 1

no. of moles of Hill = 0.005modes CHU Ht + 0) no. of moles of CH₂ CO2 H = Molarity & Volume in L = 0.loo molx oolool = 0. olmole no. of moles of CH₂ CO₂ Wa - Molarity & Volume in = 0, 100 mol x 0. look = o. of mole ka a ledoxe = 1.8ox 105 pka=- log ka H+ + CH₂ Coo- - CH₃COOH 1 0.005 oool C -0.005 -0.005 +0.005 0.015 As pH = pkat log [CH₂ coo] - [CH₃ Cook] 0.01 E o 0.005 [CH3Cook = -logka + log [CH₂ 600] pH = -log(i. Box 10°5) + loglo: 005) pH a 4.745+/-0.4771) [PH = 4.3