جمع غاز الهيدروجين

توليد الهيدروجين وجمعه من الزنك والحمض

Gas Laws Intermediate (High School) 35 دقيقة ~$10,00

الهدف

توليد غاز الهيدروجين من تفاعل الزنك مع حمض الهيدروكلوريك وجمعه بإزاحة الماء.

الخلفية

When zinc metal reacts with hydrochloric acid, hydrogen gas is produced: Zn + 2HCl → ZnCl₂ + H₂. The gas can be collected by water displacement in an inverted graduated cylinder, allowing volume measurement and mole calculations.

تحذيرات السلامة

  • Hydrogen gas is extremely flammable — NO open flames nearby
  • HCl is corrosive
  • Work in a well-ventilated area
  • Do not seal the system completely — pressure buildup risk

معدات الوقاية الشخصية المطلوبة

goggles gloves lab_coat

المواد

  • Zinc granules (5 g)
  • Hydrochloric acid (HCl) (50 mL)
    2M
  • Distilled water (500 mL)

المعدات

Erlenmeyer flask (250 mL) Rubber stopper with delivery tube Pneumatic trough or large bowl Graduated cylinder (100 mL) Rubber tubing

الإجراء

1

Fill the pneumatic trough with water. Fill the graduated cylinder with water, invert it, and place it in the trough.

5 دقيقة
2

Place 5 g zinc granules in the Erlenmeyer flask.

2 دقيقة
3

Add 50 mL of 2M HCl to the flask. Quickly insert the rubber stopper with delivery tube.

2 دقيقة HCl is corrosive
4

Direct the delivery tube under the inverted graduated cylinder. Collect the hydrogen gas by water displacement.

10 دقيقة No flames — hydrogen is flammable
5

When the reaction slows, record the volume of gas collected. Note temperature and atmospheric pressure.

3 دقيقة
6

Optionally, perform the squeaky pop test: bring a lit splint near a small collection of H₂.

3 دقيقة Very small amount only
7

Calculate moles of H₂ using ideal gas law and compare with moles predicted from zinc mass.

5 دقيقة

النتائج المتوقعة

5 g Zn = 0.076 mol should produce 0.076 mol H₂ = ~1.9 L at STP. The collected volume should be close to this when corrected for temperature and water vapor pressure.

التنظيف

Neutralize remaining acid with sodium bicarbonate. Dispose of zinc chloride solution down the drain. Rinse all equipment.

Frequently Asked Questions

What is the objective of جمع غاز الهيدروجين?
توليد غاز الهيدروجين من تفاعل الزنك مع حمض الهيدروكلوريك وجمعه بإزاحة الماء.
How difficult is جمع غاز الهيدروجين?
This experiment is rated as Intermediate (High School). It takes approximately 35 minutes to complete.
What safety precautions are needed for جمع غاز الهيدروجين?
Key safety precautions include: Hydrogen gas is extremely flammable — NO open flames nearby; HCl is corrosive; Work in a well-ventilated area.
What materials are needed for جمع غاز الهيدروجين?
The main materials required are: Zinc granules, Hydrochloric acid (HCl), Distilled water.
What results should I expect from جمع غاز الهيدروجين?
5 g Zn = 0.076 mol should produce 0.076 mol H₂ = ~1.9 L at STP. The collected volume should be close to this when corrected for temperature and water vapor pressure.