Ch. 14 Neutralization 3)Titration error 1. 용액과 지시약 1) 표준 용액 : 강산, 강염기 산 표준용액 : 염산, 과염소산, 황산(질산은 사용 × ) 염기 표준용액 : NaOH, KOH 2) 지시약 HIn + H2O ⇔ H3O+ +In- In- + H2O ⇔ HIn + OH- 지시약의 변색범위 : 3)Titration error Indicator : selection of indicator Ability of eye : depend on the change in mL of reagent at equivalent point the concentration of indicator sensitivity of eye 1 ± = pKa pH
2. Neutralization of strong acid and strong base [H3O+] : Acid, Dissociation of water HCl + NaOH ⇔ NaCl + H2O H+ + OH- ⇔ H2O ▣ Titration 0.05M-HCl 50 mL, add 0.1M-NaOH, 0.0005M-HCl 50 mL, add 0.001M-NaOHl
The Effect of concentration A : 0.05M-NaOH Add 0.1M-HCl B : 0.005M-NaOH 0.01M-HCl
3. Weak acid + strong base 초기 pH : 약산의 pH 당량점 전 : 완충용액 당량점 : 음이온의 가수분해 당량점 전 : 완충용액 당량점 : 음이온의 가수분해 당량점 후 : 강 염기
Generate a curve for the titration of 50.0.mL 0f 0.100M- Acetic acid with 0.100M- Sodium hydroxide.
The effect of concentration The effect of reaction completeness Choosing of indicators
The composition of solutions during acid/base titrations Fig. 14-8 Plots of relative amount of acetic acid and acetate ion during a titration. The straight lines show the change in relative amounts of HOAc(α0 ) and OAc-(α1 ) during the titration of 50.00 mL of 0.100M acetic acid. The curved line is the titration curve for the system.