Two Experimental Runs Are Performed to Determine the Calorimetric Properties

Multiple Choice

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 heat of fusion of the alcohol is closest to

A) 5.5 × 10⁴ J/kg.
B) 6.3 × 10⁴ J/kg.
C) 7.1 × 10⁴ J/kg.
D) 7.9 × 10⁴ J/kg.
E) 8.7 × 10⁴ J/kg.