The reagent, from the following, which converts benzoic acid to benzaldehyde in one step is




The correct answer is (A) : 

The correct order of the rate of reaction of the following reactants with nucleophile by \( \mathrm{S_N1} \) mechanism is:
(Given: Structures I and II are rigid) 
| LIST I | LIST II | ||
|---|---|---|---|
| A | Lyman | I | Near IR |
| B | Balmer | II | Far IR |
| C | Paschen | III | Visible |
| D | p-fund | IV | UV |
Let \( \alpha = \dfrac{-1 + i\sqrt{3}}{2} \) and \( \beta = \dfrac{-1 - i\sqrt{3}}{2} \), where \( i = \sqrt{-1} \). If
\[ (7 - 7\alpha + 9\beta)^{20} + (9 + 7\alpha - 7\beta)^{20} + (-7 + 9\alpha + 7\beta)^{20} + (14 + 7\alpha + 7\beta)^{20} = m^{10}, \] then the value of \( m \) is ___________.
Hydrocarbons are organic compounds that are entirely made up of only two kinds of atoms – carbon and hydrogen. Typically, hydrocarbons are colourless gases that have very weak odours.
According to experimental evidences, SE (S = substitution; E = electrophilic) reactions are supposed to proceed via the following three steps: