At the end of this lab, students should know...
電気化学は、化学反応と電気エネルギーの関係を研究する化学の一分野です。
電気化学セルは、電解質溶液を含む反応チャンバー、塩架橋、および電気的に接続された2つの導電性電極(陽極と陰極)で構成されています。
酸化還元反応、または酸化還元反応は、酸化中に電子が1つの種から失われ、還元中に別の種によって得られる一対の半反応です。還元はカソードで起こり、酸化はアノードで起こります。
出典:米国ジョンズ・ホプキンス大学(米国メリーランド州)のSmaa Koraym
ここでは、10人の学生がペアで作業するための実験室の準備を示していますが、多少の過剰さがあります。必要に応じて数量を調整してください。
| 1 マルチメータ 赤と黒のリード線 |
| 2 つのワニ口クリップ |
| 1 ガラス温度計 |
| 1 6ウェル反応プレート |
| 1組の鉗子 |
| 20 mL メスフラスコ 1 |
| 100 mL メスフラスコ |
| 1mL 容量ピペット 1 |
| 2mL容量ピペット1 |
| 100 mLビーカー 3 |
| 10 mLメスシリンダー |
| 50 mLメスシリンダー 1 |
| 1 600-mL ビーカー |
| 2 ガラス漏斗 |
Q1: How do you prepare a 0.1 M oxalic acid solution for a galvanic cells lab?
Weigh 6.304 g of oxalic acid dihydrate and transfer it to an Erlenmeyer flask. Add 500 mL of deionized water, then stir until homogeneous. Use a powder funnel to transfer the solution to a labeled polyethylene bottle and store it in the instructor's hood. Handle oxalic acid with caution as it is corrosive.
Q2: What materials are needed to prepare a salt bridge for a galvanic cell experiment?
Cut string into 2-inch pieces, with three pieces needed per group. Soak the strings in a 0.1 M potassium nitrate solution for one hour before the lab begins. This prepares the salt bridge, which maintains electrical neutrality between the two half-cells in the galvanic cell.
Q3: How should metal electrodes be prepared before use in a galvanic cells experiment?
Cut copper sheet into 2 x 9 cm pieces, zinc sheet into 2 x 6 cm pieces, and silver sheet into 2 x 6 cm pieces. Store each metal type in labeled beakers corresponding to unknown numbers. Clean metal surfaces with emery paper cut into 1 x 2 inch pieces to remove oxidation before assembly.
Q4: What is the correct procedure for preparing unknown solutions in a galvanic cells lab?
Prepare 0.05 M zinc sulfate by weighing 3.6 g and dissolving in 250 mL deionized water. Prepare 0.22 M silver nitrate by weighing 9.34 g and dissolving in 250 mL deionized water. Divide each solution into two brown glass bottles labeled with corresponding unknown numbers and store in the instructor's hood.
Q5: What equipment should be set up at each lab station for a galvanic cells experiment?
Each station requires a multimeter with leads, alligator clips, glass thermometer, 6-well reaction plate, forceps, volumetric flasks, graduated cylinders, beakers, glass funnels, and a 20-mL volumetric flask. These tools enable students to measure solutions, monitor voltage, and assemble electrochemical cells for data collection.
Q6: How do you prepare the potassium nitrate solution for the salt bridge?
Weigh 2.53 g of potassium nitrate and transfer to a flask. Add 250 mL of deionized water and stir until homogeneous. Transfer the 0.1 M solution to a labeled glass bottle and store in the instructor's hood. Use this solution to soak salt bridge strings one hour before the lab.
Q7: What safety and waste management procedures are required for a galvanic cells lab?
Wear appropriate personal protective equipment including a lab coat, chemical splash goggles, and gloves. Handle oxalic acid with caution as it is corrosive. Dedicate a 20-L container for heavy metal waste and ensure it is accessible in the hood for safe disposal of all metal-containing solutions and materials.