Two Solutions (The System), Each with a Volume of 25

Multiple Choice

Two solutions (the system) , each with a volume of 25.0 mL at 25.0°C, are mixed in a beaker. A reaction occurs between them, and the temperature rises to 35.0°C. After the products have equilibrated with the surroundings, the temperature is again 25.0°C and the total volume is 50.0 mL. No gases are involved in the reaction. Which relationship concerning the change from initial to final states (both at 25.0°C) is correct?

A) ΔU = 0
B) ΔH = 0
C) ΔU > 0
D) q = 0
E) w = 0