Report Sheet Record any changes you observe when you perform the test indicated
ID: 1058394 • Letter: R
Question
Report Sheet Record any changes you observe when you perform the test indicated in the procedure. Reactions of Hydrocarbons-Test for Unsaturation Conclusion Observation SOLUTION Reagent Added a) Which of the compounds A or B, do you think is an unsaturated hydrocarbon? Give your reason. Reactions of Aldehydes and Ketones Conclusion Observation SOLUTION Reagent Added C 2,4-dinitrophenylhydrazine D 2.4 C Tollen's reagent D Tollen's reagent C Iodine in KI D Iodine in Kl a) Which reaction is common for both aldehydes and ketones? b) Which of the above reagents is an aldehyde? c) Which of the above reagent is a methyl ketone. Give reasonsExplanation / Answer
Reactions of hydrocarbons
Test for unsaturation
1) Add Br2 water : If the color of bromine disappears, the compound is unsaturated.
2) Cold dilute KMnO4 : Purple color of KMnO4 disappears, confirms unsaturation present in compound.
Reactions of aldehydes and ketones
a) Both aldehydes and ketones gives a positive test with 2,4-dinitrophenylhydrazine. They both form colored compounds with reagent.
b) Aldehydes give postive test with Tollen's reagent. Ketones fail to undergo this reaction. A silver mirror is formed in the reaction.
c) A positive reaction with Iodine in KI shows presence of Me-ketones.
Reactions of acids and alcohols
Acids : reacts with aqueous NaHCO3 to form soluble sodium salt which can be reprecipitated by adding concentrated HCl to the aqueous layer.
Alcohols : React with strong bases as NaOH to form alkoxide in anhydrous conditions by release of H2 gas
a) Acids form salts with NaHCO3 (aq)
b) Upon reaction, E with F forms an ester. Fruity smell.
c) Ester is formed
d) Esterification reaction
Reactions of amines
HCl : addition of HCl (aq) gives salt of amine which is water soluble, reprecipitated by adding NaOH.
a) Nitrogen is the elemtn which is present in amines but absent in aldehydes or alcohols.