One half of a kilogram of liquid water at 273 K (0°C) is placed outside on a day when the temperature is 259 K(-14 °C). Assume that the heat is lost from the water only by means of radiation and that the emissivity of the radiating surface is 0.560. Consider two cases: when the surface area of the water is (a) 0.035 m² (as it might be in a cup) and (b) 1.5 m² (as it could be if the water were spilled out to form a thin sheet). For each case, (a) and (b), determine the time it takes the water to freeze into ice at 0 °C.
Energy transfer
The flow of energy from one region to another region is referred to as energy transfer. Since energy is quantitative; it must be transferred to a body or a material to work or to heat the system.
Molar Specific Heat
Heat capacity is the amount of heat energy absorbed or released by a chemical substance per the change in temperature of that substance. The change in heat is also called enthalpy. The SI unit of heat capacity is Joules per Kelvin, which is (J K-1)
Thermal Properties of Matter
Thermal energy is described as one of the form of heat energy which flows from one body of higher temperature to the other with the lower temperature when these two bodies are placed in contact to each other. Heat is described as the form of energy which is transferred between the two systems or in between the systems and their surrounding by the virtue of difference in temperature. Calorimetry is that branch of science which helps in measuring the changes which are taking place in the heat energy of a given body.
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