




To determine the correct structure of L-fructose, we must understand the stereochemistry and structure of sugars, particularly their D and L configurations.
Fructose is a ketohexose, meaning it has a ketone group at the second carbon and has six carbon atoms. The difference between D-fructose and L-fructose lies in the configuration of the asymmetric carbon atoms, specifically the chiral centers.
The D/L notation does not refer to the direct spatial arrangement (dextrorotatory or levorotatory) but rather to the stereochemistry, which relates to the structure of glyceraldehyde. In sugars, the D or L configuration is determined by the orientation of the hydroxyl group on the last chiral carbon (farthest from the ketone group) in the Fischer projection:
For L-fructose, the hydroxyl group on the last chiral carbon should be on the left in its Fischer projection.
Let's examine the given options to identify the correct structure of L-fructose:
The correct image, showing the hydroxyl group on the last chiral carbon of L-fructose positioned to the left, matches the structure in the third option:
Therefore, the correct structure for L-fructose is represented by the third option. This aligns with the characteristic organization of L-sugars.
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)

Cobalt chloride when dissolved in water forms pink colored complex $X$ which has octahedral geometry. This solution on treating with cone $HCl$ forms deep blue complex, $\underline{Y}$ which has a $\underline{Z}$ geometry $X, Y$ and $Z$, respectively, are
Number of compounds among the following which contain sulfur as a heteroatom is ___.
Compounds: Furan, Thiophene, Pyridine, Pyrrole, Cysteine, Tyrosine
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)
A black body is at a temperature of 2880 K. The energy of radiation emitted by this body with wavelength between 499 nm and 500 nm is U1, between 999 nm and 1000 nm is U2 and between 1499 nm and 1500 nm is U3. The Wien's constant, b = 2.88×106 nm-K. Then,