Question

A a 50.00-mL sample of bleach solution contains 0.289 M HClO and 0.602 M NaClO. The K_a of hypochlorous acid is 3.0 ✕ 10⁻⁸.

Find the pH of the solution.   

The solution is then divided in half.

A) To one half of the original solution, 10.00 mL of 0.100 M NaOH is added. What is the final pH of this solution?  

B) To the other half of the original solution, 1.00 mL of 0.100 M HCl is added. What is the final pH of this solution?

Answer 1

Buffer solution a buffer solution can be calculate Henden san-Hasselbalch equation, pH pra pH = pra flog a flog [Base] Tacid] [Base] = concentration of base pka = -log ke [Acid] = conantration kar Aud he know dissociation constant i molarity a moles of volume solute e in = I nsolute Hy po chlorous and is a very wear a cid it dissociates partially in solution to produce its conjugate base ng ate base chlorate in. stco can H+ + co- conjugath base. ka=3.ox 10-8 Etalo] = 0.289 [co] = 0.602M Acid According nderson-tasselbalch equation pH = pka tlog tela J -log(3.0 X10-8) + log pH = 7.522 +0.318 6 pr 7.8414 → - 0.289 pH of buffer solution (7.8414)

Then the le volume - will be = = 25 mL solution is derided of every half of ( Total volume of 50.00 ml) into half solution solution is 10.com 0.1m Naot added to 25m2 of buffer Moles Adlo present in 25 m2 = 0.289male IL - (Tom) Irro smoles of 7.225X103 mol Hadlo present 'n 25ml. 0.602more. aaott 0.1 mol 11 lo loro 1004 = 0.01505 more as, Nado +H₂O and moles = 1x183 mole The equilibrium reaction of Helo with Moon can be written ICE table telo + NaOH mitial 7-295x10 3 1x10 - 3 0.01505 - Change -lx10 3 -(x103 +1x153 Equilibrium 6.225X165 0 0.01605 Total volume of solution [telo] = 6.225x10 3 me 0.0351 and [ Nadlo) - 0.01605 male 0.03152 According to Henderson-Hasselbald ecuation, pH = pka tras Iclo] Esclo7 > $Hz-109 (3:0x108) + log T 0:016.055 0.035 25ton + 10.0omi) 35m - 7-522 +0.4113 To. 225x103 0.035 7.9341 .. The pH value after addition = 7.9340 of maat

1.00 mL goles of 0.1 m sel added to 25m2 butter of telo present in 25 m2 20.289 mole 25. moles of Maclo present in - 7. 225x15 3 more 25 ml = 0.602 molu 1L and moes of Stel addeda oil mo 01 mole. Toto x 26 1000 L - 0.015 on mole 1x10 4 mole Macho with Hee 715 + 1x104 The equilibrium real tion of can be written as- ICE table Mallot Hell Hulot mace Initial, 0.01505 1x104 7.2 25 X 10 3 0 No4. - 1xus 4 -1 бЧ +1 уточ Equilibrium, 0.01495 7.325 x103 Ixio4 Total arolume of solution = (25 m2 + 25 m2 in I Nado] = 0.01495 more 010262 and telo 7.325x10 3 more 0-026 Henderson- tasselbalch eaua pka tlog [ Nado) n JA Thulog 1.000 = 0026 Accor din, ding to VO 3-09|3008158) +log / 0.01495 ( 0.026 7-325x163 0.026 = 7.522 + 0.3107 - 7.8327 pH of buffer solution after Hell - 7.8327] addition of