電導度滴定

電気伝導度を利用して滴定を追跡する

Titrations Advanced (University) 50 分 ~$20.00

目的

指示薬の代わりに電気伝導度の測定値を用いて酸塩基滴定を行い、電導度-体積グラフから終点を決定する。

背景

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.

安全上の警告

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

必要なPPE

goggles gloves lab_coat

材料

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

器具

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

手順

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 分 Handle HCl carefully
2

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

2 分
3

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

3 分
4

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

2 分
5

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

25 分
6

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

8 分
7

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

5 分

予想される結果

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.

後片付け

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

詳細

カテゴリ
Titrations
難易度
Advanced (University)
所要時間
50 分
推定費用
$20.00
ステップ数
7
材料
3

その他の実験

EDTA錯体滴定による水の硬度測定 45 min pH滴定曲線 50 min フェノールフタレインを用いた酸塩基滴定 45 min メチルオレンジを用いた酸塩基滴定 40 min ヨウ素によるビタミンC滴定 40 min 二重指示薬による炭酸塩・重炭酸塩混合物の滴定 55 min 制酸剤錠剤の逆滴定 60 min 沈殿滴定（モール法） 45 min 漂白剤のヨウ素滴定 50 min 過マンガン酸カリウムによる酸化還元滴定 50 min

Frequently Asked Questions

What is the objective of 電導度滴定?
指示薬の代わりに電気伝導度の測定値を用いて酸塩基滴定を行い、電導度-体積グラフから終点を決定する。
How difficult is 電導度滴定?
This experiment is rated as Advanced (University). It takes approximately 50 minutes to complete.
What safety precautions are needed for 電導度滴定?
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 電導度滴定?
The main materials required are: Hydrochloric acid (HCl), Sodium hydroxide (NaOH), Distilled water.
What results should I expect from 電導度滴定?
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.