1) What would be the preferred heating device (s) in each of the following situations?

a) reflux a solvent with a 56 degree Celsius boiling point
b) reflux a solvent with a 110 degree Celsius boiling point
c) distillation of a substance that boils at 220 degree Celsius

3) What type of bath would you use to get a temperature of -10 degree Celsius?

5) Criticize the following techniques
a) Refluxing a mixture that contains diethyl ether using a Bunsen burner
b) Refluxing a mixture that contains a large amount of toluene using a hot-water bath
c) Refluxing a mixture using the apparatus shown in Figure 6.6, but with an unclamped thermometer
d) Using a mercury thermometer that is inserted into an aluminum block on a hate plate
e) Running a reaction with tert-butyl alcohol (2-methyl-2-propanol) that is cooled to 0 degree Celsius in an ice bath

What kind of heating devices do you have? Write them down. Place to the right of the unit the temperatures available with them. Then match these to boiling point, reflux temperature, flammability, etc of each of your questions. For example, you don't want to heat diethyl ether with a bunsen burner because the vapors burn easily and an explosion/fire is possible. Many a student has been burned badly in a lab when heating ether with an open flame.

what is wrong with running a reaction with the tert-butyl alcohol that is cooled to 0 degree Celsius in an ice bath?

1) In each of the following situations, the preferred heating device would be as follows:

a) To reflux a solvent with a 56 degree Celsius boiling point, a hot plate or a sand bath can be used. Both of these heating devices provide even and controlled heating, which is necessary for refluxing.

b) To reflux a solvent with a 110 degree Celsius boiling point, an oil bath would be the preferred heating device. An oil bath allows for higher temperature control and can be heated to the desired temperature without exceeding it.

c) For the distillation of a substance that boils at 220 degrees Celsius, a heating mantle or an electric heating mantle would be ideal. These mantles provide efficient and uniform heating, allowing for better control of the distillation process.

3) To achieve a temperature of -10 degree Celsius, a cryogenic bath would be suitable. Cryogenic baths use liquefied gases or refrigerants to cool down a liquid or sample to very low temperatures, such as -10 degree Celsius in this case.

5) Criticizing the following techniques:

a) Refluxing a mixture that contains diethyl ether using a Bunsen burner: This technique is not suitable because diethyl ether is highly flammable and poses a significant fire hazard. The open flame of a Bunsen burner can easily ignite diethyl ether, resulting in a dangerous situation.

b) Refluxing a mixture that contains a large amount of toluene using a hot-water bath: This technique may not be efficient for a large amount of toluene reflux because water has a lower boiling point than toluene. The hot-water bath may not be able to sustain the desired temperature for an extended period, affecting the refluxing process.

c) Refluxing a mixture using the apparatus shown in Figure 6.6, but with an unclamped thermometer: Using an unclamped thermometer can be risky during refluxing. The vibrations and movements during the process can cause the thermometer to fall and break, potentially contaminating the reaction mixture or causing injuries.

d) Using a mercury thermometer that is inserted into an aluminum block on a hot plate: This technique may not be accurate for measuring temperatures accurately, especially if there is poor thermal contact between the mercury thermometer and the aluminum block. The lack of direct contact can result in a delay in temperature reading or inaccurate measurements.

e) Running a reaction with tert-butyl alcohol (2-methyl-2-propanol) that is cooled to 0 degrees Celsius in an ice bath: Cooling tert-butyl alcohol to 0 degrees Celsius in an ice bath can be effective for some reactions, but it might not be sufficient for all reactions that require lower temperatures. It is important to consider the reaction requirements and consult the literature or experienced chemists for appropriate cooling conditions.