전도도 적정

전기 전도도를 이용하여 적정 추적하기

Titrations Advanced (University) 50 분 ~$20.00

목표

지시약 대신 전기 전도도 측정값을 사용하여 산염기 적정을 수행하고, 전도도-부피 그래프에서 종점을 결정한다.

배경

In a conductometric titration, electrical conductivity of the solution is measured as the titrant is added. Since different ions have different molar conductivities (H+ and OH- are exceptionally mobile), the conductivity changes non-linearly during titration. The endpoint is found where two straight-line segments of the conductivity curve intersect.

안전 경고

  • HCl and NaOH are corrosive
  • Wear safety goggles and gloves
  • Keep the conductivity probe away from the magnetic stirrer bar

필수 개인 보호 장비

goggles gloves lab_coat

재료

  • Hydrochloric acid (HCl) (100 mL)
    0.1M
  • Sodium hydroxide (NaOH) (100 mL)
    0.1M
  • Distilled water (200 mL)

장비

50 mL burette Burette stand and clamp 250 mL beaker Conductivity meter with probe Magnetic stirrer 25 mL pipette Graph paper

실험 절차

1

Pipette 25.0 mL of 0.1M HCl into the beaker. Add 50 mL of distilled water to increase volume for the probe.

3 분 Handle HCl carefully
2

Place the beaker on the magnetic stirrer. Insert the conductivity probe and the stir bar.

2 분
3

Record the initial conductivity reading. Fill the burette with 0.1M NaOH.

3 분
4

Add 1.0 mL of NaOH from the burette. Stir for 30 seconds, then record the conductivity and cumulative volume.

2 분
5

Repeat step 4, adding 1.0 mL increments, recording conductivity after each addition. Continue until well past the expected endpoint.

25 분
6

Plot conductivity (y-axis) versus volume of NaOH added (x-axis). Identify the two linear regions.

8 분
7

Draw best-fit lines for the two regions and find their intersection. This is the endpoint.

5 분

예상 결과

Conductivity initially decreases as highly mobile H+ ions are replaced by less mobile Na+ ions. After the endpoint, conductivity increases as excess OH- ions accumulate. The V-shaped graph clearly shows the equivalence point.

정리

Remove and rinse the conductivity probe carefully. Neutralize waste solutions before disposal. Rinse all glassware.

세부 정보

카테고리
Titrations
난이도
Advanced (University)
소요 시간
50 분
예상 비용
$20.00
단계
7
재료
3

더 많은 실험

페놀프탈레인을 이용한 산염기 적정 45 min 과망간산칼륨 산화환원 적정 50 min 표백제의 아이오딘 적정 50 min 제산제 정제의 역적정 60 min 메틸 오렌지를 이용한 산염기 적정 40 min 이중 지시약을 이용한 탄산염-중탄산염 혼합물 적정 55 min 침전 적정(모어법) 45 min 아이오딘을 이용한 비타민 C 적정 40 min EDTA 착화 적정을 이용한 물 경도 측정 45 min pH 적정 곡선 50 min

Frequently Asked Questions

What is the objective of 전도도 적정?
지시약 대신 전기 전도도 측정값을 사용하여 산염기 적정을 수행하고, 전도도-부피 그래프에서 종점을 결정한다.
How difficult is 전도도 적정?
This experiment is rated as Advanced (University). It takes approximately 50 minutes to complete.
What safety precautions are needed for 전도도 적정?
Key safety precautions include: HCl and NaOH are corrosive; Wear safety goggles and gloves; Keep the conductivity probe away from the magnetic stirrer bar.
What materials are needed for 전도도 적정?
The main materials required are: Hydrochloric acid (HCl), Sodium hydroxide (NaOH), Distilled water.
What results should I expect from 전도도 적정?
Conductivity initially decreases as highly mobile H+ ions are replaced by less mobile Na+ ions. After the endpoint, conductivity increases as excess OH- ions accumulate. The V-shaped graph clearly shows the equivalence point.