Thermosetting plastics cannot be remolded because they:
A. Have cross-linked structure
B. Melt at high temperature
C. Are linear polymers
D. Are biodegradable
Answer: Option A
Solution (By JKExamLibrary)
Thermosets (e.g., Bakelite) form extensive cross-links between polymer chains, making them rigid. Heating breaks bonds but degrades, not remolds. Thermoplastics are linear/branched.
Explanation:
CO has a triple bond: one sigma and two pi bonds, with a coordinate covalent character where oxygen donates a lone pair to carbon, forming a bond similar to triple bond. Total shared electrons = 6 (three pairs). Lewis structure shows :C≡O: with formal charges. The bond order is 3. It is isoelectronic with N₂ and CN⁻.
Explanation:
The carbon-fluorine bond is one of the strongest covalent bonds, making PTFE resistant to attack by chemicals and heat. The fluorine atoms also shield the carbon backbone.
Explanation:
Single superphosphate (SSP) is a phosphorus fertilizer, a mixture of monocalcium phosphate and gypsum, produced by treating rock phosphate with sulfuric acid: Ca₃(PO₄)₂ + 2H₂SO₄ → Ca(H₂PO₄)₂ + 2CaSO₄. Urea and ammonium nitrate are nitrogenous fertilizers. Potassium chloride is a potash fertilizer. Phosphorus promotes root development and flowering.
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