Consider the dissolution of CaCl2: CaCl2(s) -> Ca²⁺(aq) + 2Cl⁻(aq), ΔH = -81.5 kJ. An 11.6 g sample of CaCl2 is dissolved in 126 g water, with both substances at 24.3°C. Calculate the final temperature of the solution assuming no heat loss to the surroundings. What is the final temperature of the solution?

A 1.3 g wafer of pure gold initially at 69.8 °C is submerged into 64.1 g of water at 26.9 °C in an insulated container. The specific heat capacity for gold is 0.128 J/g°C and the specific heat capacity for water is 4.18 J/g°C. What is the final temperature of the system when thermal equilibrium is reached?

A piece of iron (mass = 25.0 g) at 398 K is placed in a styrofoam coffee cup containing 25.0 mL of water at 298 K. Assuming that no heat is lost to the cup or the surroundings, what will the final temperature of the water be? The specific heat capacity of iron is 0.449 J/g·K and the specific heat capacity of water is 4.18 J/g·K.

A sheet of gold weighing 10.0 g and at a temperature of 18.0°C is placed on a sheet of iron weighing 20.0 g and at a temperature of 55.6°C. What is the final temperature of the combined metals? The specific heats of iron and gold are, respectively, 0.444 J/g°C and 0.129 J/g°C.

An 80.0 g sample of metal, initially at 96.0 °C, is placed into 150.0 g of water initially at 26.0 °C in a calorimeter. The final temperature of the water is 28.1 °C. What is the identity of the metal? (The specific heat of water is 4.18 J/g°C.)

Given 352 mL of water at 26 °C in a perfectly heat-insulating container, how much ice at 0 °C (in grams) would have to be added to this water so that after the ice has melted, the overall temperature of the system has been lowered to 5 °C?

How much energy is needed to vaporize 75.0 g of diethyl ether (C4H10O) at its boiling point (34.6 °C), given that ΔHvap of diethyl ether = 26.5 kJ/mol?

How much energy must be removed from a 125 g sample of benzene (molar mass = 78.11 g/mol) at 425.0 K to liquify the sample and lower the temperature to 335.0 K? The following physical data may be useful: ΔHvap = 33.9 kJ/mol, ΔHfus = 9.8 kJ/mol, Cliq = 1.74 J/g·K.

How much heat is released when 125.0 g of steam at 100.0°C is cooled to ice at -15.0°C? The enthalpy of vaporization of water is 40.67 kJ/mol, the enthalpy of fusion for water is 6.01 kJ/mol, the molar heat capacity of liquid water is 75.4 J/(mol·°C).