Download App

Question Bank [2022] — Chemistry STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceChemistryQuestion Bank [2022]3 Marks
Question
What is Grignard reagent? How is it prepared? Why are they prepared under anhydrous condition?
✓

Answer

  1. Grignard reagent: When alkyl halide is treated with magnesium in the dry ether as the solvent, it gives alkyl magnesium halide. This is known as the Grignard reagent.
  2. The Grignard reagent can be prepared as,
    $\underset{\text { Alkyl halide }}{ R - X }+ Mg \stackrel{\text { dry ether }}{\longrightarrow} \underset{\text { Alkyl magnesium halide (Grignard reagent) }}{ R - Mg - X }$
  3. Grignard reagents are highly reactive compounds.
  4. They react with water or compounds containing hydrogen attached to the electronegative element.
    Hence, reactions involving Grignard reagent must be carried out under anhydrous condition.

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 "Answer the following in brief." from Question Bank [2022]→Question Bank [2022] — all question types→Chemistry STD 12 Science question papers→Maharashtra Board STD 12 Science question papers→Maharashtra Board question paper generator→

Similar questions

What is the action of following reagents on acetaldehyde?
Acidified potassium dichromate
→
The standard enthalpy of combustion of formaldehyde $\Delta_c H^0=-571 kJ$.
How much heat will be evolved in the formation of $22 g$ of $CO _2$ ?
→
The hydration enthalpies of $Li ^{+}{ }_{( g )}$, and $Br _{( g )}^{-}$are $-500 kJ mol ^{-1}$ and $-350 kJ mol ^{-1}$ respectively and the lattice energy of $\operatorname{LiBr}_{(s)}$ is $807 kJmol ^{-1}$. Write the thermochemical equations for enthalpy of solution of $LiBr ( s )$ and calculate its value.
→
Why is molecularity applicable for only elementary reactions whereas order of a reaction is applicable for elementary and complex reactions? Explain with suitable examples.
→
What will be the magnetic moment of transition metal having 3 unpaired electrons?
(a) equal to 1.73 B.M.?
(b) less than 1.73 BM.
(c) more than 1.73 B.M.?
→
Explain why the solution of $Ti ^{3+}$ salt is purple in colour.
Why is $Ti ^{3+}$ coloured? $($atomic number $Ti = 22)$
→
How is propan-l-ol prepared using diborane?
→
Write the chemical reaction involved in the formation of ethyl amine using acetaldoxime .
→
A compound forms hexagonal close packed (hcp) structure. What is the number of (i) Octahedral voids (il) Tetrahedral voids (iii) Total voids formed in 0.4 mol of it?
→
A current of 6 amperes is passed through $AlCl _3$ solution for 15 minutes using Pt electrodes, when $0.504 g Al$ is produced. What is the molar mass of $Al$ ?
→