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कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान 2nd PUC Class 12

Which of the following reagents can be used to oxidise primary alcohols to aldehydes? (i) CrOX3 in anhydrous medium. (ii) KMnOX4 in acidic medium. (iii) Pyridinium chlorochromate. (iv) Heat in the - Chemistry

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प्रश्न

Which of the following reagents can be used to oxidise primary alcohols to aldehydes?

(i) \[\ce{CrO3}\] in anhydrous medium.

(ii) \[\ce{KMnO4}\] in acidic medium.

(iii) Pyridinium chlorochromate.

(iv) Heat in the presence of Cu at 573 K.

टीपा लिहा
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उत्तर

(i) \[\ce{CrO3}\] in anhydrous medium.

(iii) Pyridinium chlorochromate.

(iv) Heat in the presence of Cu at 573 K.

Explanation:

Strong oxidising agents such as acidified potassium permanganate are used for getting carboxylic acids from alcohols directly. \[\ce{CrO3}\] in anhydrous medium is used as the oxidising agent for the isolation of aldehydes.

\[\ce{RCH2OH ->[CrO3] RCHO}\]

A better reagent for the oxidation of primary alcohols to aldehydes in good yield is pyridinium chlorochromate (PCC), a complex for chromium trioxide with pyridine and HCl.

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पाठ 11: Alcohols, Phenols and Ethers - Multiple Choice Questions (Type - I) [पृष्ठ १५८]

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एनसीईआरटी एक्झांप्लर Chemistry [English] Class 12
पाठ 11 Alcohols, Phenols and Ethers
Multiple Choice Questions (Type - I) | Q 19 | पृष्ठ १५८

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\[\begin{array}{cc}
\phantom{............}\ce{CH2OH}\\
\phantom{......}|\\
\ce{CH3 - CH2 - CH - CH - CH - CH3}\\
\phantom{......}|\phantom{............}|\phantom{.}\\
\phantom{........}\ce{CH2Cl}\phantom{......}\ce{CH3}\phantom{}
\end{array}\]


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\[\begin{array}{cc}
\phantom{................}\ce{CH3}\\
\phantom{.............}|\\
\ce{CH3 - CH - CH - C - CH3}\\
|\phantom{......}|\phantom{......}|\\
\phantom{...}\ce{CH3\phantom{.}}\phantom{..}\ce{OH}\phantom{...}\ce{CH3}
\end{array}\]


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|\phantom{......}|\phantom{......}|\\
\phantom{...}\ce{CH3}\phantom{...}\ce{OH}\phantom{...}\ce{CH3}
\end{array}\]


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