When 15.0 g of a salt was dissolved in 68.8 g of ethyl alcohol, the temperature of the solution decreased from 25.0 °c to 6.0 °c. the specific heat capacity for ethyl alcohol is 2.440 j/g°c. calculate the heat of reaction (∆h) in units of kj/g. (equation 1 and equation 2 will be .)

Explanation:

As we know that,

It is given that, = 15 g of salt,   = 68.8 g of ethanol

Therefore, total mass is as follows.

    Total mass =

                       = (15 + 68.8) g

                       = 83.8  g

Also, change in temperature is as follows.

              dT =

                    =

Now, the relation between heat energy, specific heat and mass is as follows.

               Q =

                   =

                   = -3884.968 J

Therefore, heat of the reaction is as follows.

                       =

                      = 258.99 J/g

As 1 J = 0.001 kJ. So, heat of reaction in kJ is 0.2589 kJ/g.

Thus, we can conclude that heat of reaction is 0.2589 kJ/g.

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.