اختبار CO₂ وماء الجير
الكشف عن ثاني أكسيد الكربون بهيدروكسيد الكالسيوم
الهدف
توليد غاز ثاني أكسيد الكربون من تفاعل كربونات-حمض وتأكيد هويته باستخدام اختبار ماء الجير.
الخلفية
When baking soda (sodium bicarbonate) reacts with vinegar (acetic acid), CO₂ gas is produced. Bubbling this gas through limewater (calcium hydroxide solution) produces a characteristic white milky precipitate of calcium carbonate, confirming the presence of CO₂.
تحذيرات السلامة
- Limewater is mildly irritating — avoid eye contact
- CO₂ is an asphyxiant in large quantities — work in ventilated area
معدات الوقاية الشخصية المطلوبة
المواد
-
Baking soda (NaHCO₃) (10 g)
-
White vinegar (50 mL)5% acetic acid
-
Limewater (Ca(OH)₂ solution) (100 mL)Clear, saturated
المعدات
الإجراء
Pour 100 mL of clear limewater into a test tube or small beaker.
Place 10 g of baking soda in the Erlenmeyer flask.
Add 50 mL of vinegar to the flask. Quickly insert the stopper with delivery tube.
Direct the delivery tube into the limewater. Bubble the CO₂ through for 2-3 minutes.
Observe the limewater turning milky white as calcium carbonate precipitate forms.
Continue bubbling. If enough CO₂ passes through, the solution may turn clear again as soluble Ca(HCO₃)₂ forms.
النتائج المتوقعة
The clear limewater turns milky white due to CaCO₃ precipitation: Ca(OH)₂ + CO₂ → CaCO₃ + H₂O. With excess CO₂, the milkiness clears: CaCO₃ + CO₂ + H₂O → Ca(HCO₃)₂.
التنظيف
Neutralize remaining vinegar solution. Dispose of limewater down the drain. Rinse all equipment.
التفاصيل
- الفئة
- Gas Laws
- الصعوبة
- Beginner (Middle School)
- المدة
- 20 دقيقة
- التكلفة التقديرية
- $5,00
- الخطوات
- 6
- المواد
- 3