Safety tion se care to avoid contact with solid sodium hydroxide or the reaction

Question

Safety tion se care to avoid contact with solid sodium hydroxide or the reaction mixture. D Place 0.25 g of 3,4-dimethox ybenzaldehyde and 0.20 g of 1-indanone in a test tube. Using a metal spatula, scrape and crush the two solids together until they become a brown oil. Use care to avoid breaking the test tube. Add 0.05 g of freshly ground (using a mortar and pestle) solid NaoH to the reaction mixture and continue scraping until the mixture becomes solid. Allow the mixture to stand for 15 minutes, and then add about 2 mL of a 10% aqueous HCl solution. Scrape well in order to dislodge the product from the walls ofthe test tube. Check the pH ofthe solution to make sure it is acidic. Isolate the solid product be suction filtration, continuing to pull air through the solid to facilitate drying. Determine the mass of the product. Recrystallize the product from 90% ethanolw 10% water, using the hot solvent first to rinse any remaining product from the test tube. You should not require more than 20 mL ofsolvent to effect this recrystallization. The precipitate may be very fine and resist filtration. If so, you can use a centrifuge to help isolate the product. Ensure the material is fully dried before the next step Determine the mass and melting point of the recrystallized product. (typical range is 178-181 c) Prelab questions. Explain why upon mixing of the two solids does the mixture become a brown oil. 1) 2) Why does the reaction become a solid again after the addition ofthe catalytic amount of NaoH? 3) often mixed reactions can result in multiple products. If both starting materials have acidic alpha protons, the addition of the base will create two carbanions (aka which can act as a nucleophile. Likewise, the unprotonated ketones can both act as electrophiles. This may produce a total of 4 possible products. Why does this mixed adol reaction result in only one major pr

Explanation / Answer

a)

This becomes brown oil, since NaOH material is pretty caustic, so it will react with the base to form a "Brown" mix

b)

After adding NaOH, the catalyst, you will hava an aqeuous mix, therefore, the solid forms again

c)

This occurs mainly due to the kinetics and thermodynamics of the reaction, even though 4 possible products are possible to form, the kinetics of the reaciton favour only 1 specie, since it is the "fastest" rate

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.