Question

A) a solution that is made by combining 55 mL of 5.0×10−2 M hydrofluoric acid with 125 mL of 0.11 M sodium fluoride Express your answer using two decimal places.

pH=

B) Calculate the percent ionization of 0.125 M lactic acid in a solution containing 8.5×10−3 M sodium lactate.

C) A 75.0-mL volume of 0.200 M NH3 (Kb=1.8×10−5) is titrated with 0.500 M HNO3. Calculate the pH after the addition of 15.0 mL of HNO3. Express your answer numerically.

pH=

Answer 1

A) we know that, PKA OG HF = 3.17 CHF] = Molasity x volume = Sxox55mL dela = 2.75MM [Naf) – Molosity x volume 20:11M X125 ml = 1375 mm. let us consides a reaction, PH = pka +log (Salt) Cacid = 3.17+109 (13.75mm) Thy 2175 mm) = 3:17 + 0.6989 P = 3.86 @9) tx B) let us consider aveaction, CH3 CH (OH)2001 (00) = CH3 CH (OH) c056e) +47 0.125 0.0085 -20 +2 0.125-2 0.0085+2 X we know that, (CH3 CH (OH) 000] (14+) (CH3CH (OH2COOH)

1.4x154 - x (0.008577), 0.125 -2 010000175 -0.000143C = 0.0085% +x? 2c270.008646-010000175 -0. on solving, we get 7.-bĚ Jb2-490 29 x=0.00169 -010086455 (0.008643246 (accee CX)=(H+) 201 CHF)= 0.00169M (X2) 0100169 Percent ionization C X100% (CH3 CHĽ014) COH 0100169 xd 2X100 0:125 = 0101352 X 100 Percent ionization = 1.35%

C) Millimoles of NH3 = maasity x volume = 0,200 x 75 =15 Mullimoles of HNO3 = Molasity x volume e = 7.5 let is consider consides a reaction a reaction, NH3 + HNO3 -> Mityt + NO3 15 7. 5 0 7.5 0 715 Here salt and base pemained - So, it fooms basic buffer PKb Of NH3 = -10g (ks) =tog (1.8x105) =4.75 POH = Prb+10g alerte = 4.75+109 (7:5) =4.75 to POH = 4.75 P4*- PO14 = 14 PH = 14 -POH = 14-4175 [PH = 9125)