Acetophenone (C 6 H 5 COCH 3) contains the group CH 3 CO attached to carbon and hence given iodoform test while benzophenone does not contain this group and hence does not give iodoform test.. C 6 H 5 COCH 3 (Acetophenone) + 3I 2 + 4 NaOH → CHI 3 + C 6 H 5 COONa (Iodoform) + 3 NaI + 3 H 2 O . (a) (i) Benzoic acid on warming with sodium hydrogen carbonate gives brisk effervescence of CO 2 gas while ethyl benzoate does not respond to this test (ii) Benzaldehyde and acetophenone Iodoform test: Acetophenone being a methyl ketone on treatment with I 2 /NaOH undergoes Iodoform reaction to give yellow ppt. Answer: (c) Aldol. In this experiment you will explore a variant of the haloform reaction, using bleach as the oxidizing agent. We will take the reagents as being iodine and sodium hydroxide solution. one year ago Think You Can Provide A Better … This is because acetaldehyde, acetone and acetophenone contains a methyl group beside the carbonyl group or the alpha position. Answer: (b) Pentan-2-one will give iodoform test. Which benzophenone does not give iodoform test . The presence of hydroxide ions is important for the reaction to happen - they take part in the mechanism for the reaction (not required for UK A level). On the other hand, benzaldehyde does not give this test. Which compound is obtained when acetaldehydes are treated with dilute solution of caustic soda? of iodoform but benzaldehyde does not. Answer. Step 1: First, an acid-base reaction. Answer: (a) Question 33. C6H5COCH3 + 3I2 + 4NaOH give CHI3 + C6H5COONa + 3NaI + 3 H2O C6H5COC6H5 + I2 + NaOH give no reaction C6H5COC. Acetophenone, being a methyl ketone on treatment with I2/NaOH undergoes iodoform reaction to give a yellow ppt. The first stage involves substitution of all three hydrogens in the methyl group by iodine atoms. The compound should have CH3CO group to show iodoform test . Iodoform test is used to check the presence of carbonyl compounds with the structure R-CO-CH3 or alcohols with the structure R-CH(OH)-CH3 in a given unknown substance. The group to which the CH 3 —CO group is attached can be aryl, alkyl and hydrogen. The iodoform test is commonly used as a test for the CH 3 —CO group. By Iodoform test: Acetophenone being a methyl ketone on treatment with I 2 and NaOH (NaOI) undergoes iodoform test to give yellow ppt. Question 32. (ii) CH 3 COOH (Acetic acid) and HCOOH (Formic acid). Fill in the reagents for the given conversation: Answer. of iodoform. Mechanism of the Classic Iodoform Reaction. Iodoform test In this test, Acetaldehyde, acetone, and acetophenone were able to exhibit the formation of yellow precipitate after it was added to 10% KI solution (Potassium Iodide) and NaClO. Equations for the triiodomethane (iodoform) reaction. of iodoform on heating whereas benzaldehyde does not. (a) Sodium acetate (b) Resinous mass (c) Aldol (d) Ethyl acetate. Question 34. The compound should have CH 3 CO-group to show the iodoform test. Acetophenone (C6H5COCH3) contains the group CH3CO attached to carbon and hence give iodoform test . The reaction of iodine, a base and a methyl ketone gives a yellow precipitate along with an “antiseptic” smell.