8.1. Aldehydes and ketones — Chemistry STD 12 Science — Question

Statement $I$: Aqueous solution of $K _2 Cr _2 O$, is preferred as a primary standard in volumetric analysis over $Na _2 Cr _2 O$, aqueous solution

Statement $II:$ $K _2 Cr _2 O$, has a higher solubility in water than $Na _2 Cr _2 O _7$

In the light of the above statements, choose the correct answer from the options given below:

$\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Br}+\mathrm{Z}^{-}$$\xrightarrow[{{\text{Sublimation}}}]{{{k_s}}} \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Z}+\mathrm{Br}^{-}$

$\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Br}+\mathrm{Z}^{-}$$\xrightarrow[{{\text{elimination}}}]{{{k_e}}}\mathrm{CH}_{3} \mathrm{CH}= \mathrm{CH}_{2} +\mathrm{HZ}+\mathrm{Br}^{-}$

where 

$\mathrm{Z}^{-}=\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{O}^{-}(\mathrm{A})$ or $\begin{array}{*{20}{c}}
  {\,C{H_3}} \\ 
  {|\,\,\,\,\,} \\ 
  {C{H_3} - C - {O^ - }(B)} \\ 
  {|\,\,\,\,} \\ 
  {\,\,C{H_3}} 
\end{array}$

$\mathrm{k}_{\mathrm{s}}$ and $\mathrm{k}_{\mathrm{e}},$ are $,$ respectively, the rate constants for the substitution and elimination, and $\mu=\frac{\mathrm{k}_{\mathrm{s}}}{\mathrm{k}_{\mathrm{e}}},$ the correct options is

$(A)$ A secondary alcohol on oxidation gives a ketone

$(B)$ Ethanol reacts with conc. ${H_2}S{O_4}$ at ${180\,^o}C$ to yield ethylene

$(C)$ Methanol reacts with iodine and sodium hydroxide to give a yellow precipitate of iodoform

$(D)$ Hydrogen gas is liberated when sodium is added to alcohol. Select the correct statements from the above set:

Statement $I :$ The limiting molar conductivity of $\mathrm{KCl}$ (strong electrolyte) is higher compared to that of $\mathrm{CH}_{3} \mathrm{COOH}$ (weak electrolyte).

Statement $II :$ Molar conductivity decreases with decrease in concentration of electrolyte.

In the light of the above statements, choose the most appropriate answer from the options given below: