Calorimetry: Two experimental runs are performed to determine the calorimetric properties of an alcohol that has a melting point of -10°C. In the first run, a 200-g cube of frozen alcohol, at the melting point, is added to 300 g of water at 20°C in a styrofoam container. When thermal equilibrium is reached, the alcohol-water solution is at a temperature of 5.0°C. In the second run, an identical cube of alcohol is added to 500 g of water at 20°C and the temperature at thermal equilibrium is 10°C. The specific heat of water is 4190 J/kg · K. Assume that no heat is exchanged with the styrofoam container and with the surroundings. The specific heat of the alcohol is closest to
A) 1700 J/kg · K.
B) 1900 J/kg · K.
C) 2100 J/kg · K.
D) 2300 J/kg · K.
E) 2500 J/kg · K.

Question

Quizplus · Accepted Answer

The heat gained by the alcohol equals the heat lost by the water. By setting up the heat balance equations for both runs and solving for the specific heat of the alcohol, the value closest to 2100 J/kg·K is obtained.

Calorimetry: Two Experimental Runs Are Performed to Determine the Calorimetric