Question

Two solutions, initially at 24.69°C, are mixed in a coffee cup calorimeter (Ccal = 105.5 J/°C). When a 200.0 mL volume of 0.100 M AgNO3 solution is mixed with a 100.0 mL sample of 0.100 M NaCl solution, the temperature in the calorimeter rises to 25.16°C. Determine the DH°rxn, in units of kJ/mol AgCl. Assume that the density and heat capacity of the solutions is the same as that of water. Hint: Write a balanced reaction for the process.Two solutions, initially at 24.69°C, are mixed in a coffee cup calorimeter (Ccal = 105.5 J/°C). When a 200.0 mL volume of 0.100 M AgNO3 solution is mixed with a 100.0 mL sample of 0.100 M NaCl solution, the temperature in the calorimeter rises to 25.16°C. Determine the DH°rxn, in units of kJ/mol AgCl. Assume that the density and heat capacity of the solutions is the same as that of water. Hint: Write a balanced reaction for the process.-64 kJ/mol AgCl-32 kJ/mol AgCl-78 kJ/mol AgCl-25 kJ/mol AgCl-59 kJ/mol AgCl

Answer 1

-64 kJ/mol

Step-by-step explanation:

For the reaction:

AgNO₃ + NaCl → AgCl + NaNO₃

The heat of calorimeter is:

105,5 J/°C × (25,16°C - 24,69°C) = 49,59 J

The total volume of the solutions is 200,0mL + 100,0mL = 300,0mL ≡ 300,0g. Using this value, the heat generated in the water is:

4,184J/g°C × 300,0g × (25,16°C - 24,69°C) = 589,9J

As the heat of reaction is:

`q_(reaction) = - (q_(calorimeter) + q_(solution))`

`q_(reaction) = - (49,59J + 589,9J)`

-639,5 J

As moles of AgCl are 0,1L × 0,100M (NaCl solution, limiting reagent) = 0,01 moles, ΔH reaction is:

-639,5 J / 0,01 moles = -63950 J/mol ≡ -64 kJ/mol

I hope it helps!