Usage of technical grade ether for extraction in Grignard Synthesis.

[zoner]

---

Members don't see this ad.

Hello

I wasn't sure about one of my lab question. Hope someone can clarify this for me. The question was, "Technical grade ether contains small amounts of ethanol and water. Why is it all right to use technical grade ether for the extraction, after you were so careful to avoid moisture in the early steps or the reaction?"

The extraction was of the alcohol product that was formed by reacting Gignard reagent with and aldehyde. The solution we used was diethyl ether, but we used technical grade ether while washing out the aqueous layer.

if anyone can help, that would be great! Thanks

 

[BerkReviewTeach]

Hello

I wasn't sure about one of my lab question. Hope someone can clarify this for me. The question was, "Technical grade ether contains small amounts of ethanol and water. Why is it all right to use technical grade ether for the extraction, after you were so careful to avoid moisture in the early steps or the reaction?"

The extraction was of the alcohol product that was formed by reacting Gignard reagent with and aldehyde. The solution we used was diethyl ether, but we used technical grade ether while washing out the aqueous layer.

if anyone can help, that would be great! Thanks

I assume you are going to get the "no homework allowed" hammer dropped on you, so I'll try to address your question with that violation in mind.

Let me ask a question in MCAT format that will hopefully help you walk the path to the answer.

• If a reactant is water sensitive, but a product is not, then would it be okay to add water once the reaction is complete?
  
  A) No, because some of the unreacted starting material may still be present.
  B) No, because water could push the product back to reactant, which will then react with the water.
  C) Yes, because the reaction is completed and collecting the product will not shift the reaction back.
  D) Yes, because the water helps convert the unreacted reactant into product.

 

[zoner]

Thanks for that... I will never do this again here, but I swear I saw a post before where someone was asking a homework question before...


the answer is (c)🙂

 

[Charles_Carmichael]

I assume you are going to get the "no homework allowed" hammer dropped on you

Indeed.

Sorry zoner, but this is not the place for homework help. Closing thread.