Điện Phân Nước

Phân hủy nước thành khí hydro và oxy

Electrochemistry Intermediate (High School) 40 phút ~$15,00

Mục tiêu

Phân hủy nước thành khí hydro và oxy bằng điện phân, và xác minh tỷ lệ thể tích 2:1 theo tính toán hóa học lượng.

Bối cảnh

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.

Cảnh báo an toàn

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

PPE cần thiết

goggles lab_coat

Vật liệu

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

Thiết bị

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

Quy trình

1

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

3 phút
2

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

5 phút
3

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

3 phút
4

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

2 phút
5

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

20 phút 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 phút
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 phút Use small quantities for gas tests

Kết quả dự kiến

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).

Dọn dẹp

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

Chi tiết

Danh mục
Electrochemistry
Độ khó
Intermediate (High School)
Thời gian
40 phút
Chi phí ước tính
$15,00
Số bước
7
Vật liệu
3

Thí nghiệm khác

Các Phương Pháp Chống Rỉ Sét 30 min Chế Tạo Pin Daniell 45 min Điện Phân Đồng Sunfat 50 min Đo Điện Thế Pin Voltaic 60 min Kiểm Tra Dãy Hoạt Động Hóa Học 30 min Mạ Điện Đồng 60 min Pin Chanh 20 min Pin Nồng Độ 45 min

Frequently Asked Questions

What is the objective of Điện Phân Nước?
Phân hủy nước thành khí hydro và oxy bằng điện phân, và xác minh tỷ lệ thể tích 2:1 theo tính toán hóa học lượng.
How difficult is Điện Phân Nước?
This experiment is rated as Intermediate (High School). It takes approximately 40 minutes to complete.
What safety precautions are needed for Điện Phân Nước?
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 Điện Phân Nước?
The main materials required are: Distilled water, Sodium sulfate (Na₂SO₄), Universal indicator.
What results should I expect from Điện Phân Nước?
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).