Practical skills assessment video - making butyl ethanoate video 1 : heating under reflux

Summary

In this video series, viewers learn the step-by-step process of preparing a pure sample of butyl ethanoate, an ester. The first part covers the essential steps of mixing reactants— butan-1-ol and ethanoic acid— in a round-bottomed flask, adding sulfuric acid as a catalyst, and setting up a reflux system to prevent loss of volatile chemicals. The mixture is heated using a Bunsen burner, ensuring smooth boiling and preventing excessive vapor escape. This introductory video sets the stage for the complete esterification process, with further steps to be explored in the following parts.

Takeaways

• 😀 The video demonstrates how to prepare a pure sample of an organic liquid, using butyl ethanoate as the example.
• 😀 Equal amounts in moles of butan-1-ol and ethanoic acid are mixed in a round-bottomed flask.
• 😀 0.25 moles of both butan-1-ol and ethanoic acid are used in the reaction.
• 😀 A catalyst, concentrated sulfuric acid, is required for the reaction to proceed.
• 😀 Sulfuric acid must be added drop-by-drop to prevent overheating the mixture.
• 😀 Swirling the flask while adding sulfuric acid ensures even mixing and prevents hot spots.
• 😀 The reaction proceeds slowly at room temperature, so heating is necessary.
• 😀 A reflux condenser is used to prevent volatile reactants and products from escaping.
• 😀 The reflux condenser is clamped to the neck of the round-bottomed flask, and water flows through it to maintain the temperature.
• 😀 The mixture is heated using a Bunsen burner with a tripod and gauze to ensure even heating.
• 😀 The mixture should be heated for 30 minutes to allow the reaction to complete, with vapors condensing and returning to the flask in a reflux process.

Q & A

What is the purpose of this video series?

The purpose of this video series is to demonstrate how to prepare a pure sample of an organic liquid, specifically the ester butyl ethanoate.

What reactants are used in this experiment?

The reactants used in this experiment are butan-1-ol (an alcohol) and ethanoic acid (a carboxylic acid).

What is the required molar amount of each reactant?

The required amount of each reactant is 0.25 moles of both butan-1-ol and ethanoic acid.

Why is concentrated sulfuric acid added to the mixture?

Concentrated sulfuric acid is added as a catalyst to speed up the reaction between butan-1-ol and ethanoic acid.

How should the sulfuric acid be added to the reaction mixture?

The sulfuric acid should be added drop-by-drop to the flask to prevent an exothermic reaction that could cause the mixture to overheat.

Why is it important to swirl the flask while adding sulfuric acid?

Swirling the flask ensures that the mixture is evenly heated and that no part of the mixture becomes too hot, which could cause overheating or uneven reactions.

Why is heating necessary for this reaction?

Heating is necessary because the reaction between the reactants is slow at room temperature, and the heat helps to speed up the reaction.

What is the purpose of using a reflux condenser in this experiment?

A reflux condenser is used to prevent volatile chemicals from escaping into the air by allowing the vapors to condense and return to the flask, ensuring that the mixture does not lose any material.

What precautions should be taken when connecting the reflux condenser?

When connecting the reflux condenser, the neck of the flask should be clamped, anti-bumping granules should be added to prevent uneven boiling, and the condenser should be greased and connected to a tap for water flow.

How is the temperature controlled during the heating process?

The temperature is controlled by adjusting the flow of gas into the Bunsen burner to ensure that the mixture boils smoothly without excessive vigor. A tripod and gauze are used to evenly heat the flask.

What happens to the mixture during the boiling process?

During the boiling process, the mixture undergoes reflux, meaning that the vapors condense and return to the flask, preventing any loss of material from the system.

How long should the mixture be heated?

The mixture should be heated for 30 minutes to allow the reaction to proceed adequately.