Question

Fenedict's reagent contains Cuations that are reduced to Cult when the carbonyl group is xidized. Cul+ ions form a brick red precipitate, Cu20, in aqueous solution. The remaining lution varies from green through yellow to red, depending on the initial concentration of ne carbohydrate. A positive test indicates that the carbohydrate is, indeed, a reducing arbohydrate. Pre-lab Preparation 1. Write Fischer projections for the following sugars and identify any chiral carbons with a *: D-erythrose and L-erythrose Define enantiomer, diastereomer and meso compound. Give the value for the specific rotation for sucrose and provide a reference. Carefully review how to take a polarimeter reading as described below. Experimental Procedure

Answer 1

сно Cно Chinal eaubens HD- H-K он H HO- CH,OH CH2OH D-ey thrae L-engthraue 2 Enantiemau Rach Chinal matecules that ase miwigu images athir Auch that those misva images enantiomers FAuporimpaable are nem Bm one anather aue kneusn a Diastoueomen Diastuuomers are wtouois omeres uhch ane nen-mwior images & non-identical. Diastuaomaus haue dilenent camigrations at DD Br maue Ateecevtbes but not all saeh pthor &me o the m&thus, are not imaga of Meco ompund mirsior Aeocentres & A meso compound s a maleeule which hos mang inagu on ita movro Aupari mpoca le 3 Bucre is a disacchasids made up ot two monaaechanides glucse &Buutiave ueroe Cdaueare t Fruuctode Co= 52.0 Ca=-92.49 ox]- 66.50 The Apecific gutation aueno , as pen anditeatue valua,