Question

a solution that is made by combining 55 mL of 4.0×10−2 M hydrofluoric acid with 125 mL of 0.11 M sodium fluoride

Answer 1

solution ... given that Combining ^ 55 mL of off if so combining with 4-07102M Hf, with 125 ml of all Maf. i total volume of buffer solution is - volume of haft volume of HF - 125ml +55mL = 180m2 molanty of HF in final buffer CVI = (2 V2 & la concentrations GX 180 I 40x1024x55 m2 4.= 4.0x10 mxosmx 180 ml @ @ To = 7-22X10? RC =0.0122 ] molanty of Naf in final buffer ari Flavq ax 180 F 0.11 MX 125 ml (12 Oll8120 180 20'076M

concentration we. have both HF. of rear and HF - Http ka = [H][F] = 7.2 X164 [HP] ( taken from wild base strength) : Ka= 7.28104 pkas-log kq = 3.142 Noo, we know? Henderson- Hasselbalch equation estimation of pH of buffer solution. ;V ph 2. pkat 109 [Nar) for Dh2 pka't log THAT por = 0 3747 3 3:14 + 0.0122 6 0.7944 [p4= 3.934]