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Karnataka Board PUCPUC Science 2nd PUC Class 12

Give a simple chemical test to distinguish between the following pair of compounds: Ethanal and Propanal

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Questions

Give a simple chemical test to distinguish between the following pair of compounds:

Ethanal and Propanal

Give a chemical test to distinguish between propanal and ethanal.

Chemical Equations/Structures
Distinguish Between
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Solution

Ethanal Propanal
Ethanal gives a yellow precipitate on heating with iodine in the presence of sodium hydroxide (positive Iodoform test). Propanal will not give any reaction on heating with iodine in the presence of sodium hydroxide (negative Iodoform test).

Ethanal gives the iodoform test, but propanal does not.

\[\ce{CH3CHO + \underset{Hypoiodite}{\underset{Sodium}{3NaOI}} ->[NaOH/I2][Heat] HCOONa + \underset{yellow ppt}{CHI3\downarrow} + 2NaOH}\]

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Chapter 8: Aldehydes, Ketones and Carboxylic Acids - Exercises [Page 256]

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NCERT Chemistry Part 1 and 2 [English] Class 12
Chapter 8 Aldehydes, Ketones and Carboxylic Acids
Exercises | Q 8.13 (vii) | Page 256

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