물의 전기분해

물을 수소와 산소로 분해하기

Electrochemistry Intermediate (High School) 40 분 ~$15.00

목표

전기분해로 물을 수소와 산소로 분해하고, 화학양론으로 예측되는 2:1 부피 비를 검증한다.

배경

Water electrolysis uses electrical energy to drive the non-spontaneous decomposition of water. At the cathode, water is reduced to hydrogen gas; at the anode, water is oxidized to oxygen gas. A small amount of electrolyte (sulfuric acid or sodium sulfate) is added to increase conductivity.

안전 경고

  • Hydrogen gas is flammable — no open flames nearby
  • Do not use excessive voltage (above 12V)
  • Ensure proper ventilation

필수 개인 보호 장비

goggles lab_coat

재료

  • Distilled water (500 mL)
  • Sodium sulfate (Na₂SO₄) (5 g)
    Electrolyte
  • Universal indicator (5 mL)
    Optional, to show pH changes

장비

9V battery or DC power supply Two graphite or platinum electrodes Two inverted graduated cylinders or test tubes Beaker (600 mL) Wires with alligator clips Stand and clamps

실험 절차

1

Dissolve 5 g of sodium sulfate in 500 mL of distilled water in the beaker.

3 분
2

Fill two graduated cylinders completely with the solution and invert them over the electrodes in the beaker.

5 분
3

Connect the electrodes to the DC power supply or battery. Note which electrode is connected to positive (anode) and negative (cathode).

3 분
4

Turn on the power supply and observe gas bubbles forming at both electrodes.

2 분
5

Collect gas in the inverted cylinders for 15-20 minutes, recording the volume at each electrode every 5 minutes.

20 분 Keep flames away — hydrogen is flammable
6

Compare the volumes of gas collected. The cathode (H₂) should collect twice the volume of the anode (O₂).

3 분
7

Optionally, test the cathode gas with a lit splint (squeaky pop test for H₂) and the anode gas with a glowing splint (relights for O₂).

3 분 Use small quantities for gas tests

예상 결과

The cathode should collect approximately twice the volume of gas as the anode, confirming the 2:1 ratio of H₂ to O₂. If universal indicator is added, the solution near the cathode turns blue/purple (basic) and near the anode turns red/orange (acidic).

정리

Disconnect the power supply. Dispose of the solution down the drain. Rinse and dry the electrodes.

세부 정보

카테고리
Electrochemistry
난이도
Intermediate (High School)
소요 시간
40 분
예상 비용
$15.00
단계
7
재료
3

더 많은 실험

황산구리 전기분해 50 min 다니엘 전지 제작 45 min 활동도 순서 확인 30 min 농도 전지 45 min 레몬 전지 20 min 구리 전기도금 60 min 볼타 전지 기전력 측정 60 min 녹 방지 방법 비교 30 min

Frequently Asked Questions

What is the objective of 물의 전기분해?
전기분해로 물을 수소와 산소로 분해하고, 화학양론으로 예측되는 2:1 부피 비를 검증한다.
How difficult is 물의 전기분해?
This experiment is rated as Intermediate (High School). It takes approximately 40 minutes to complete.
What safety precautions are needed for 물의 전기분해?
Key safety precautions include: Hydrogen gas is flammable — no open flames nearby; Do not use excessive voltage (above 12V); Ensure proper ventilation.
What materials are needed for 물의 전기분해?
The main materials required are: Distilled water, Sodium sulfate (Na₂SO₄), Universal indicator.
What results should I expect from 물의 전기분해?
The cathode should collect approximately twice the volume of gas as the anode, confirming the 2:1 ratio of H₂ to O₂. If universal indicator is added, the solution near the cathode turns blue/purple (basic) and near the anode turns red/orange (acidic).