Easy MCQ +4 / -1 PYQ · JEE Mains 2023

Better method for preparation of $\mathrm{BeF}_{2}$, among the following is :

  1. A $$\mathrm{BeH}_{2}+\mathrm{F}_{2} \stackrel{\Delta}{\longrightarrow} \mathrm{BeF}_{2}$$
  2. B $$\left(\mathrm{NH}_{4}\right)_{2} \mathrm{BeF}_{4} \stackrel{\Delta}{\longrightarrow} \mathrm{BeF}_{2}$$ Correct answer
  3. C $\mathrm{Be}+\mathrm{F}_{2} \stackrel{\Delta}{\longrightarrow} \mathrm{BeF}_{2}$
  4. D $$\mathrm{BeO}+\mathrm{C}+\mathrm{F}_{2} \stackrel{\Delta}{\longrightarrow} \mathrm{BeF}_{2}$$

Solution

According to the NCERT (s block) textbook, the better method for the preparation of BeF₂ is heating (NH₄)₂BeF₄. <br/><br/> Option B : <br/><br/> $$\left(\mathrm{NH}_{4}\right)_{2} \mathrm{BeF}_{4} \stackrel{\Delta}{\longrightarrow} \mathrm{BeF}_{2} + 2\mathrm{NH}_{4}\mathrm{F}$$ <br/><br/> This method involves the thermal decomposition of ammonium beryllium fluoride ((NH₄)₂BeF₄) to form beryllium fluoride (BeF₂) and ammonium fluoride (NH₄F). The reaction is more efficient compared to other options and results in a purer product.

About this question

Subject: Chemistry · Chapter: s-Block Elements · Topic: Alkali Metals

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