Câu 2: (0,5 đ) Tính số ml H3PO4 85% (d=1,69 g/ml) phải lấy để hòa tan vào nước và pha loãng thành 500 ml thì pH = 3.
Biết axit H3PO4 có có pKal=2,15; pKaz=7,31; pKa3= 12,32.

Answer asap need by wednesday morning explain how a buffer works, using an ethanoic acid/sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.