مقارنة معدل الانتشار (قانون غراهام)

مقارنة معدلات انتشار غازي HCl وNH₃

Gas Laws Intermediate (High School) 30 دقيقة ~$10,00

الهدف

التحقق من قانون غراهام للانتشار بمقارنة معدلات سريان غازي HCl وNH₃ عبر أنبوب زجاجي.

الخلفية

Graham's law states that the rate of diffusion of a gas is inversely proportional to the square root of its molar mass. When HCl (36.5 g/mol) and NH₃ (17 g/mol) diffuse toward each other in a tube, they form a white ring of NH₄Cl where they meet. The ring forms closer to the HCl end because NH₃ diffuses faster.

تحذيرات السلامة

  • Concentrated HCl fumes are corrosive and irritating
  • Concentrated ammonia fumes are irritating
  • Perform this experiment in a fume hood or well-ventilated area
  • Do not inhale either gas directly

معدات الوقاية الشخصية المطلوبة

goggles gloves lab_coat

المواد

  • Concentrated hydrochloric acid (5 mL)
    For HCl fumes
  • Concentrated ammonia solution (5 mL)
    For NH₃ fumes
  • Cotton wool (2 pieces)
    For soaking

المعدات

Glass tube (1 m long, 2 cm diameter) Rubber stoppers (2) Ruler Retort stand and clamps Stopwatch

الإجراء

1

Clamp the glass tube horizontally on the retort stand.

3 دقيقة
2

In a fume hood, soak one cotton ball in concentrated HCl and another in concentrated ammonia.

2 دقيقة Fume hood — both gases are irritating
3

Simultaneously insert the HCl cotton ball into one end and the NH₃ cotton ball into the other end. Stopper both ends.

2 دقيقة Work quickly
4

Start the timer. Watch for a white ring of NH₄Cl to form where the two gases meet.

10 دقيقة
5

When the white ring appears, stop the timer. Measure the distance from each end to the ring.

3 دقيقة
6

Calculate the ratio of distances: d(NH₃)/d(HCl) should equal √(M(HCl)/M(NH₃)) = √(36.5/17) = 1.46.

5 دقيقة

النتائج المتوقعة

The white NH₄Cl ring should form approximately 60% of the way from the HCl end (40% from the NH₃ end), since NH₃ diffuses 1.46 times faster than HCl. The ratio d(NH₃)/d(HCl) should be approximately 1.4-1.5.

التنظيف

Remove cotton balls and dispose in fume hood. Rinse the glass tube with water. Ventilate the area.

التفاصيل

الفئة
Gas Laws
الصعوبة
Intermediate (High School)
المدة
30 دقيقة
التكلفة التقديرية
$10,00
الخطوات
6
المواد
3

مزيد من التجارب

اختبار CO₂ وماء الجير 20 min التحقق من قانون بويل 40 min الحجم المولي للغاز عند الظروف القياسية 35 min الغواص الديكارتي 15 min جمع غاز الهيدروجين 35 min ضغط البخار ونقطة الغليان 45 min قانون شارل مع بالون 30 min قياس حجم غاز مع المغنيسيوم 40 min

Frequently Asked Questions

What is the objective of مقارنة معدل الانتشار (قانون غراهام)?
التحقق من قانون غراهام للانتشار بمقارنة معدلات سريان غازي HCl وNH₃ عبر أنبوب زجاجي.
How difficult is مقارنة معدل الانتشار (قانون غراهام)?
This experiment is rated as Intermediate (High School). It takes approximately 30 minutes to complete.
What safety precautions are needed for مقارنة معدل الانتشار (قانون غراهام)?
Key safety precautions include: Concentrated HCl fumes are corrosive and irritating; Concentrated ammonia fumes are irritating; Perform this experiment in a fume hood or well-ventilated area.
What materials are needed for مقارنة معدل الانتشار (قانون غراهام)?
The main materials required are: Concentrated hydrochloric acid, Concentrated ammonia solution, Cotton wool.
What results should I expect from مقارنة معدل الانتشار (قانون غراهام)?
The white NH₄Cl ring should form approximately 60% of the way from the HCl end (40% from the NH₃ end), since NH₃ diffuses 1.46 times faster than HCl. The ratio d(NH₃)/d(HCl) should be approximately 1.4-1.5.