Enthalpy Change During The Interaction Between Acetone and Chloroform

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Thermodynamics is a branch of physics that explains the properties of heat and reactions of eat energy with different chemicals. As a part of this, here we are going to understand the release in heat due to the interaction between acetone and chloroform, which can be termed as enthalpy change. Let's see the experiment's detailed explanation to evaluate the enthalpy change during interaction between acetone and chloroform. 


Enthalpy Change Definition

The enthalpy change definition can be explained in several ways. We can explain the sum of both internal energy and the product of volume and pressure in simple terms. 

H= E+ PV

Where H = Enthalpy change

            E = Internal Energy

            P = Pressure

            V = Volume


Aim

To evaluate the enthalpy change during the interaction between acetone and chloroform.


Explanation

According to Raoult Law, when we mix two liquid pairs, they will interact with each other and behave ideally. In contrast to the Raoult law, the interaction of acetone and chloroform showed non-ideal behaviour due to the formation of hydrogen bonds and released in thermal energy. This deviation against the Raoult Law encouraged several scientists to investigate this. Hence, some theoretical and experimental studies have taken place. 

The respective chemical equation is as follows- 

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The formation of hydrogen bonds during acetone and chloroform interaction reduces the escaping tendency among the acetone and chloroform. It leads to breaking the expectations on released vapour pressure. Besides this, both molecules hold weak van der Waal forces at their pure state. At this moment, we can observe the enthalpy change during interaction with the formation of hydrogen bonds. Hence the enthalpy change of reaction was observed for a specific amount. 


Required Materials to Perform Experiment

To determine the enthalpy change during the interaction between acetone and chloroform, we need to perform an experiment that requires the following list of materials. 

  • Boiling tube

  • Glass rod

  • Cotton wool

  • Beaker

  • Chloroform

  • Measuring cylinder

  • Piece of cardboard

  • Thermometer

  • Acetone

Step by Step Procedure

Let see the step-by-step procedure to find out the enthalpy change during the interaction between acetone and chloroform. 

  • First, we need to calculate the water level, whether it should be equivalent to the level of the beaker or calorimeter.

  • Take equal amounts of both acetone and chloroform; let's say 50 mL of the solution in two different beakers separately.

  • Record the temperature of both the solutions initially to find out the enthalpy change at the end of the experiment.

  • Now we need to transfer the specific amount of chloroform from the beaker to the insulated boiling tube. Use a measuring cylinder to measure exactly 0.1 moles of chloroform.

  • And do the same thing for acetone also using a clean measuring cylinder. We should not use the same cylinder, in which we have measured the chloroform.

  • Now transfer 0.1 moles of acetone which we have connected into the chloroform in an insulated boiling tube.

  • Stir the mixture of acetone and chloroform. 

  • Start recording the temperature.

  • Now calculate the rise in temperature using the observations.

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Observations

Water level  equivalent of calorimeter

W g

The initial temperature of acetone and chloroform at the beginning of the experiment

t1°C

The final temperature of acetone and chloroform at the end of the experiment

t2°C

Density of acetone

0.787 g/cm³

Specific heat of acetone S2

2.18 J/g

Density of chloroform

1.499 g/cm³

Specific heat of chloroform S1

0.96 J/g

Change in temperature

(t1-t2)°C


Calculations

From the observations, we can calculate and find the enthalpy change of formation. It is measured in Joules. 

The formula for enthalpy change is,

= W*4.2*(t1-t2)+[100*1.499*s1 +100 *0.787*s2](t1-t2) joules

= ______ joules.

Hence it is the result obtained when we mixed 100ml of both acetone and chloroform to find out the enthalpy change during the interaction. 


Precautions to be Taken

For every experiment, you want to take necessary precautions to avoid unnecessary risks and adverse effects of chemicals. Similarly, for this experiment, we also need to take some precautions. They are listed below- 

  • We should measure the quantity of acetone and chloroform carefully to get the exact value.

  • One should be more attentive and careful while steering the mixture of acetone and chloroform.

  • Using cotton for thermal insulation is always suggestible.

  • Use a graduated thermometer and record the values of changing temperature carefully.

  • Approach the doctor immediately if any chemical splits on the skin accidentally.

  • Use gloves, glasses, masks, etc., to protect sense organs.

Conclusion

Hence, the experiment has proved that 1 mole of acetone and chloroform will show non-ideal behaviour, resulting in enthalpy change during the interaction. One should follow all the precautions while experimenting with yielding good results.

FAQs (Frequently Asked Questions)

1. What is the Importance of Enthalpy Change?

A. The enthalpy change during the interaction between acetone and chloroform plays a significant role in thermodynamics because it gave a new path to find the temperature rise. The enthalpy change also helps to determine the type of reaction, whether it is endothermic or exothermic. The enthalpy change is positive for an endothermic reaction, whereas it is negative for an exothermic reaction. 


It also helps in the throttling process or Joule-Thomson expansion. It is used to calculate the flow of heat and reactions of heat. It also measures the power of the compressor. So, the enthalpy change is very important in chemistry.

2. Define Raoult Law.

A. Raoult is a french chemist who has done several experiments in Chemistry. In 1887, he had confessed to a law called Raoult Law. According to this law, the mole fraction of any solvent is directly proportional to the vapour pressure of an ideal solution. It means if two liquid pairs interact with each other, they behave ideally.

3. Does the Enthalpy of an Ideal Gas Depend on its Temperature?

A. Yes, of course. The enthalpy of an ideal gas depends on its temperature because the temperature only can determine the internal energy, which is a part of enthalpy change. So, automatically, it depends on temperature.