Answer : The enthalpy of reaction
is, 67.716 KJ/mole
Explanation :
First we have to calculate the moles of
and
.


Now we have to calculate the moles of AgCl formed.
The balanced chemical reaction will be,

As, 1 mole of
react with 1 mole of
to give 1 mole of 
So, 0.005 mole of
react with 0.005 mole of
to give 1 mole of 
The moles of AgCl formed = 0.005 mole
Total volume of the solution = 50.0 ml + 50.0 ml = 100.0 ml
Now we have to calculate the mass of solution.
Mass of the solution = Density of the solution × Volume of the solution
Mass of the solution = 1.00 g/ml × 100.0 ml = 100 g
Now we have to calculate the heat.

where,
q = heat
C = specific heat capacity = 
m = mass = 100 g
= final temperature = 
= initial temperature = 
Now put all the given values in the above expression, we get:


Now we have to calculate the enthalpy of the reaction.

where,
= enthalpy of reaction = ?
q = heat of reaction = 338.58 J
n = moles of reaction = 0.005 mole
Now put all the given values in above expression, we get:

Conversion used : (1 KJ = 1000 J)
Therefore, the enthalpy of reaction
is, 67.716 KJ/mole