To solve the problem, we analyze the reaction sequence starting from L-glucose to find the major product Q.
1. Step i) Reaction with HI and heat (\(\Delta\)):
- The sugar undergoes cleavage of C-O bonds by HI.
- This reduces glucose to a mixture of iodoalkanes (polyiodo compounds).
- The carbon skeleton remains but oxygen atoms are replaced by iodine.
2. Step ii) Oxidation with Cr\(_2\)O\(_3\), high temperature and pressure:
- Iodoalkanes are oxidized to form fully chlorinated cyclic hydrocarbons (via halogen exchange).
- Oxygen atoms are removed, and the carbon framework becomes a chlorinated cyclic structure.
3. Step iii) Treatment with excess Cl\(_2\) under UV:
- Further chlorination occurs, leading to a hexachlorinated cyclohexane derivative.
4. Structure of the final product Q:
- Hexachlorocyclohexane (all positions chlorinated).
- This corresponds to structure (D).
Final Answer:
Option (D)
A temperature difference can generate e.m.f. in some materials. Let $ S $ be the e.m.f. produced per unit temperature difference between the ends of a wire, $ \sigma $ the electrical conductivity and $ \kappa $ the thermal conductivity of the material of the wire. Taking $ M, L, T, I $ and $ K $ as dimensions of mass, length, time, current and temperature, respectively, the dimensional formula of the quantity $ Z = \frac{S^2 \sigma}{\kappa} $ is:
Let $ a_0, a_1, ..., a_{23} $ be real numbers such that $$ \left(1 + \frac{2}{5}x \right)^{23} = \sum_{i=0}^{23} a_i x^i $$ for every real number $ x $. Let $ a_r $ be the largest among the numbers $ a_j $ for $ 0 \leq j \leq 23 $. Then the value of $ r $ is ________.
Let $ y(x) $ be the solution of the differential equation $$ x^2 \frac{dy}{dx} + xy = x^2 + y^2, \quad x > \frac{1}{e}, $$ satisfying $ y(1) = 0 $. Then the value of $ 2 \cdot \frac{(y(e))^2}{y(e^2)} $ is ________.