To determine the enthalpy change during interaction (Hydrogen Bond formation) between acetone and chloroform.

 To determine the enthalpy change during interaction (Hydrogen Bond formation) between acetone and chloroform.

Requirements:

A 250 ml thermos flask with two holes, thermometer, beakers, measuring cylinder, etc.

Chemical Required

Acetone (100ml) and Chloroform (100 ml)

Theory:

                                                

The reaction between acetone and chloroform is exothermic. It is an example of a solution that shows-ve deviation from Raoult's law. When both are mixed, the intermolecular hydrogen bond is formed. Thus the vapor pressure of the solution is less than that expected. ΔHmix is negative for such a solution because energy is released due to an increase in attractive forces.

Procedure:

1. Put 100ml acetone in a thermos flask. Note its temp. 
2. Put 100ml chloroform in a beaker and note its temperature
3. The temp. of chloroform and acetone should be the same.
4. Add the chloroform into the beaker containing acetone.
5. Stir the mixture and note the constant tempature of the mixture.

Observations and Calculations:-

Initial temperature of acetone and chloroform=t 1°C

Final temperature of liquid mixture=t ₂°

Rise in tempature = (t ₂ -t 1  )°C 

Volume of chloroform taken = 100ml.

Specific heat of choroform-2.18 J/g (S₁)

Specific heat of acetone = 0.96 J/g (S₂)

Water Equivalent of calorimeter = w gram

 The volume of acetone taken 100ml,

Density of chloroform =1.499 g/ml 

Density of acetone = 0.787 g/ml

Heat evolved on heating acetone and chloroform =

                                              = Heat gained by beaker + Heat gained by chloroform 

                                                  + Heat gained by acetone

                                              =w × 4.2 × (t₂-t₁) + 100 × 1.499 × 2.18 × (t₂-t₁) +100 × 787 × 0.96                                                                                                                                                                    × (t₂-t₁)                                                              

                                               = [ w × 4.2 + 100 × 1.499 × 2.18+100 × 787×96] (t₂-t₁)

                                              = ________ Joules.

. 

Precautions:-

Chloroform and acetone should be transferred immediately after measuring as these are volatile.

Result

Enthalpy change during mixing of 100ml of acetone with 100 ml of chloroform =  - x   Joules.

Let me know if you have more questions or if there is a specific topic that you would like to know more about.