A second student places a hot sample of iron into cold water. Her data is shown below. What
was the mass of the sample of metal she placed into the cold water? Enter your answer to the
nearest whole number of grams.

Mass of cold water: 100 g
Initial temperature of water: 20.0°C
Specific heat of iron:
0.449 J/gºC
Initial temperature of iron: 80.0°C
Equilibrium temperature of system:
42.5°C

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.