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.

a. - 78 kJ/mol AgCl

b. - 25 kJ/mol AgCl

c. - 64 kJ/mol AgCl

d. - 32 kJ/mol AgCl

e. - 59 kJ/mol AgCl

Question

Chemistry

Slade Golden

23 February, 20:26

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.

a. - 78 kJ/mol AgCl

b. - 25 kJ/mol AgCl

c. - 64 kJ/mol AgCl

d. - 32 kJ/mol AgCl

e. - 59 kJ/mol AgCl

+2

Answers (1)

Know the Answer?

Barbara Frey · Answer 1

You've got twice as much AgNO3 as NaCl, so NaCl is the limiting reactant.

(0.1000 L) x (0.100 mol/L NaCl) = 0.0100 mol NaCl

(4.184 J/g·°C) x (200.0 g + 100.0 g) x (25.16 - 24.69) °C = 589.944 J

(589.944 J) / (0.0100 mol) = 58994 J/mol = 58.99 kJ/mol