Polymerization of HCHO and CH₃CHO occurs in the presence of?
- Conc. H₂SO₄
- Dil. H₂SO₄
- Conc. H₂CO₃
- Dil. H₂CO₃
Explanation
Aldehydes like formaldehyde (HCHO) and acetaldehyde (CH₃CHO) undergo polymerization in the presence of acidic catalysts.
For the options provided, the correct catalyst is Conc. H₂SO₄.
Polymerization process for these two aldehydes:
Formaldehyde (HCHO)
With acid catalysts:
- In the presence of an acid such as concentrated sulfuric acid, formaldehyde can polymerize to form cyclic trimers and tetramers.
- The most common product is 1,3,5-trioxane, a cyclic trimer.
General polymerization:
- Formaldehyde readily polymerizes even in neutral or basic conditions to form paraformaldehyde, a straight-chain polymer.
- Acetaldehyde (CH₃CHO)
With acid catalysts:
- Acetaldehyde, when treated with strong acids like concentrated sulfuric acid, trimerizes to form paraldehyde, a cyclic trimer.
- At lower temperatures, it can also form the cyclic tetramer, metaldehyde.
With acid/base catalysts:
- Acetaldehyde also undergoes aldol polymerization, which can be initiated by both acidic and basic catalysts to form different products.
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اس سوال کو وضاحت کے ساتھ پڑھیں
- 10–20 minutes
- 30–60 minutes
- 2–4 hours
- 12–24 hours
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- Vertical drop fall
- Glacis fall
- Montague type fall
- Inglis fall
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آکسیجن زیادہ تر عناصر کے ساتھ عمل کرکے دو عنصری مرکبات بناتی ہے جنہیں کیا کہتے ہیں؟
- Bases
- Oxides
- Acids
- None of these
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پانی اور کاربن ڈائی آکسائڈ کے سالمے مل کر کیا بناتے ہیں؟
- Nitric acid
- Carbonic acid
- Sulfuric acid
- None of these
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