Question

A buffer solution contains 0.366 M KHCO, and 0.233 M NaCO3. Determine the pH change when 0.066 mol HBr is added to 1.00 L of the buffer. pH change =

Answer 1

H.COM Ź acid coz?-+ 40 conjugats base: 0.233 M. 0.366 M Using Henderson - Hasselbalch Equation pH = pka - Love 10 [ conjugate base] Cacid] pit10.3worse Conte] V = 10.3 + (-0.196) = 10.3 -0.196 = 10:104. Now after the addition of 0.066 mol HBQ. 0.233 -0.066 -0.000 . . 6.366 + 0.066 = 0.167 m 0.432. [conjugate base] H eka ing [acid] = 10.3 + = 10.3 + Wy Woo Lo.167] = 10.712. 76.432.7 = 10.3 +0.412 .: Change in p" 10.712 - 10.104 = 0.608 – change in pH = 0.6 0.6

HNO acid Ž HO + 8 conjugak buse. 0.311M 0. 294 M. pka - 3.346. using Henderson. Hassel balch Equation pH = pka + oy [conjugale base] pka Loy [Nos - 10 [auid] =) pH = 3.346+ Lois ro.294 7 = 3-346-0.024 10 10.311 J = 3.322. CANOT H .pl - 3.322. after the addition of 0.089 mol kolt, then. 1 H NO +884 Ž Ng + ko. (0.311 -0.089) M. (0-294 +0.089)m. = 0.222M 0.383m. pH = pra + lwg [anyugate base] = 3.346+ los [= 383] [auid} 10 [0.222) - 3.346 +0.2368 a change in PH = 3.5828 3:5828 – 3.322 . Change in 0.2608 0.26 PM 20-26,