Download App

Organic Chemistry: Some Basic Principles and Techniques — Chemistry STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceChemistryOrganic Chemistry: Some Basic Principles and Techniques1 Mark
MCQ
In Lassaigne's test, a blue colour is obtained if the organic compound contains nitrogen. The blue colour is due to the formation of :
  • A
    $ \mathrm{K}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right] $
  • ✓
    $\mathrm{Fe}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]_3 $
  • C
    $ \mathrm{Na}_3\left[\mathrm{Fe}(\mathrm{CN})_6\right] $
  • D
    $\mathrm{Cu}_2\left[\mathrm{Fe}(\mathrm{CN})_6\right] $
✓

Answer

Correct option: B.
$\mathrm{Fe}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]_3 $
If nitrogen is present in the organic compound then sodium extract contains $\text{NaCN}.$
$\text{Na}+\text{C}+\text{N}\xrightarrow{\text{Fuse}}\text{NaCN}$
$\text{FeSO}_4+6\text{NaCN}\rightarrow\text{Na}_4[\text{Fe(CN)}_6]+\text{Na}_2\text{SO}_4$
It changes to prussian blue $\mathrm{Fe}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]_3$ on reaction with $\mathrm{FeCl}_3$.
$4\text{FeCl}_3+3\text{Na}_4[\text{Fe(CN)}_6]\rightarrow\text{Fe}_4[\text{Fe(CN)}_6]_3+12\text{NaCl}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from Organic Chemistry: Some Basic Principles and Techniques→Organic Chemistry: Some Basic Principles and Techniques — all question types→Chemistry STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Solubility product of silver bromide is $5.0 \,\,\times \,\,10^{-13}$ . The quantity of potassium
bromide (molar mass taken as $120\,\,g\,mol^{-1}$ ) to be added to $1\,L$  of  $0.05\,\,M$  solution of silver nitrate to start the precipitation of  $AgBr$  is 
→
The value of molar gas constant is :
→
Which of the following is not correctly matched :
→
Which of the following is most acidic
→
The bond order of $O_2^ + $ is the same as in
→
A bond with maximum covalent character between non-metallic elements is formed
→
Number of hybrid orbitals of $C$ atoms in $C(CN)_4$ which have $33\%\, P$ character :-
→
From the following pairs of ions which one is not an iso-electronic pair?
→
Identify wrong statement

$R - C \equiv C - R\xrightarrow{{Pd/BaS{O_4}}}A$

$R - C \equiv C - R\xrightarrow{{Na/Liq.\,NH_3}}B$

→
In the molecule $CH_3C \equiv CCH = CH_2$ the maximum number of carbon atoms arranged linearly is
→