Question

3. Tollen's Test Result + or- Functional Group Compound Observations/Conclusions acetone propanal unknown 4. Lucas Test Functional Group Alcohol Result Compound Observations Conclusions 1-butanol 2-butanol 2-methyl-2-propanol unknown 5. Iodoform Test Result +or-) Active Methyl? Compound Observations/Conclusions 2-pentanone 3-pentanone 1-butanol 2-butanol unknown

Answer 1

Tollen�s reagent is a solution of silver nitrate in ammonia. When this reagent is treated with aldehyde and alpha - hydroxy ketone. Here is the general reaction given below. 2[Ag(NH_3)_2]^+ + RCHO + H_2 O rightarrow 2 Ag (s) + 4 NH_3 + RCOOH + 2H^+ As we see in the reaction, the ammonical silver nitrate oxidizes aldehyde to acid and it gets reduced to silver which is forms a layer on the walls of the test tube. This is called silver mirror. This test is used to distinguish between aldehyde and ketone, where aldehyde gets oxidized more easily than ketone by silver nitrate in ammonia. A solution of anhydrous zinc chloride in concentrated hydrochloric acid is known as Lucas�s reagent. It is used to differenciate between type of alcohols based on their reactivity to form carbocation. Here is the decreasing order of alcohols that forms carbocation with ease. Tertiary alcohol > secondary alcohol > primary alcohol ROH + HCl rightarrow Rcl + H2O