A 7.37 g sample of an unknown salt (MM = 116.82 g/mol) is dissolved in 150.00 g water in a coffee cup calorimeter. Before placing the sample in the water, the temperature of the salt and water is 23.72°C. After the salt has completely dissolved, the temperature of the solution is 28.54°C. Given that 157.37 g of solution increased in temperature by 4.82 °C, what quantity of heat, in J, was gained by the solution? Assume the specific heat of the solution is the same as water, 4.184 J/g･°C.

11.8 g of a soluble ionic compound is dissolved in 91.6 mL of water in a coffee-cup calorimeter, and the temperature of the solution changes from 24.80°C to 29.14°C. Assume the water has a density of 1.00 g/mL and that the total mass of the solution has the specific heat of water (4.186 J/g.K). Calculate the enthalpy change for the dissolution of this substance in kJ.

When a solid dissolves in water, heat may be evolved or absorbed. The heat of dissolution (dissolving) can be determined using a coffee cup calorimeter. In the laboratory a general chemistry student finds that when 0.90 g of CaCl2(s) are dissolved in 102.10 g of water, the temperature of the solution increases from 22.90 to 24.48 °C. The heat capacity of the calorimeter (sometimes referred to as the calorimeter constant) was determined in a separate experiment to be 1.79 J/°C.Based on the student's observation, calculate the enthalpy of dissolution of CaCl2(s) in kJ/mol. Assume the specific heat of the solution is equal to the specific heat of water.ΔHdissolution = kJ/mol

4. In a coffee-cup calorimeter, 3.20 g of NH4NO3 is mixed with 86.00 g of water at an initial temperature of 23.53°C. After dissolution of the salt, the final temperature of the calorimeter contents is 21.32°C. Assuming the solution has a heat capacity of 4.184 J/g °C and assuming no heat loss to the calorimeter, calculate the enthalpy change for the dissolution of NH4NO3 in units of kJ/mol.