Question

Calculate the pH of a solution that is 0.260 M in sodium formate (HCOONa) and 0.100 M in formic acid (HCOOH).

Calculate the pH of a solution that is 0.500 M in pyridine (C5H5N) and 0.430 M in pyridinium chloride (C5H5NHCl).

Calculate the pH of a solution that is made by combining 55 mL of 0.060 M hydrofluoric acid with 125 mL of 0.100 M sodium fluoride

Answer 1

for formic As we know Pka Рk, RY PS , 3.5 Pyridine Pkb = 8.77 curd is = 3.75 we know Henderson Messerbulch egnehron, pH= Pka + lug [A] [han & pon-pky + nog {sost] WP 4COona} = 0.260m [ Meooss] = 0.1m PM= 3.75+ lay lo.260) (0.1) = 3.75+ 0.4149 = 4.164 = 4.2 - pH of sowhon = 412

хы - [ 'я, 7 • •50 m С ъв) 43 м Ре) K-ая .: By Henderson Hesseboulich exmatron, Ря - 8-79 +" ( ) O: S ° 3-+ + (- о. oks ) - 8 +, . ( ри + p°И - 14) PH 8.2 вя - 14 - Ру - 5.3 : pm oi Johəрт = 5-3

. Number of many of usa - 0.06 mollLX0.0552 n HA = 0.0033 more mones of Nuf = 0.1 mos 12x 0.125 L = 0.0125 mole .. By using Henderson pra 3 alt meg Hesselbalch egration, To.0125 0.0033 = 3.1 + 0.578 = 3.678 = 3.68 pn of somnion = 3.68