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9) Which of following is an anomeris pair? A) D-glucose and D-fructose B) D-gluc

ID: 146926 • Letter: 9

Question

9) Which of following is an anomeris pair? A) D-glucose and D-fructose B) D-glucose and L-fructose C) D-glucose and L-glucose D) a-D-glucose and B-D-glucose E) a-D-gluose and B-L-glucose 10) What is the hybridization of the central atom in a water molecule? A) Tetrahedral B) Sp C) sp2 D) sp3 E) Trigonal pyramidal F) Bent G) Linear 11) Which of following statements about water is NOT true? A) The hybridization of the central atom in a water molecule is SP3 B) Pure water is lightly ionized C) Free proton exists in water, D) The geometry of a water molecule is bent. E) The mobility of proton is higher than that of potassium ion 12) Which of the following molecules are amphiphilic? A) Glycine B) Glycerol C) Phosphatidylcholine D) Glucose E) Wax

Explanation / Answer

9) D

10) D

H2O has 2(1) + 6 = 8 valence electrons. H2O has a tetrahedral arrangement of the electron pairs about the O atom that requires sp3 hybridization. Two of the four sp3 hybrid orbitals are used to form bonds to the two hydrogen atoms, and the other two sp3 hybrid orbitals hold the two lone pairs on oxygen.

11) E

12) B

Glycerol, if to be classified into one of biomolecular classes, it would be that of monosaccharides (in the form of sugar alcohol like sorbitol and xylitol). Glycerol is not lipid (short chain polyol, so it is polar and water soluble), but fatty acids (amphiphilic) and triglycerides (hydrophobic) are.