Ethyl bromide experiment

Summary

This experiment is from the official website of Jimei University

Operation method

Ethyl bromide experiment

Materials and Instruments

Round-bottomed flasks Conical flasks Hollow stoppers

Move

Apparatus: organic synthesis preparation apparatus

2 100 mL round-bottomed flasks; 2 150 mL conical flasks; 1 hollow stopper; 1 500 mL beaker; 1 vacuum pick-up tube; 75 °C elbow; distillation head; straight condenser tube; 1 thermometer 100 °C; thermometer casing; 2 dispensing funnels; 10 mL measuring cylinder; 250 mL heating jacket, dropping tube.

Drugs: 95 % ethanol, concentrated sulfuric acid, sodium bromide solid.

Experimental setup:

Add 10 mL of 95% ethanol and 9 mL of water to a 100 mL garden-bottom flask. Under constant shaking and cooling, add 19 mL of concentrated sulfuric acid to the flask. A mixture of ice and water should be placed both inside and outside the receiver to prevent volatile loss of product. The branch of the receiver tube is run into a sewer or outdoors with a rubber hose. The reaction mixture is heated and distilled over an asbestos screen over low heat so that the reaction occurs smoothly until no oily substance is distilled.

The distillate was poured into a separatory funnel, and the organic layer was placed in a 150 mL dry conical flask in an ice-water bath, and concentrated sulfuric acid was added dropwise while shaking, until the sulfuric acid layer was separated from the bottom of the conical flask. The sulfuric acid solution was separated with a dry separatory funnel, and the crude product of ethyl bromide was poured into a dry distillation flask, distilled with heat in a water bath, and cooled in an ice-water bath outside the receiver to collect the fraction at 37~40 °C. The product was then separated from the sulfuric acid solution with a dry separatory funnel, and then poured into a dry distillation flask. Weigh and calculate the yield.

The b.p. of pure ethyl bromide is 38.4 °C, 1.4239.

Caveat

1. The device should be tight.

2. Add concentrated sulfuric acid should be added while shaking to cool, and then add sodium bromide after sufficient cooling (in the ice water bath) to prevent the reaction from exothermic wash out.

3. Heating should be the first small fire, gradually slightly larger, so that the reaction occurs smoothly, to avoid large fires, otherwise the loss of products, and by-products are generated.

4. Refinement should be thoroughly separated from the water first, add sulfuric acid under cooling, otherwise add sulfuric acid to generate heat so that the product volatilization loss.

5. The last distillation attention to drying.

6. Product acceptance quality or volume and refractive index.

For more product details, please visit Aladdin Scientific website.

https://www.aladdinsci.com/