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Molar heat capacity

From Simple English Wikipedia, the free encyclopedia

The molar heat capacity of a substance is the energy needed to raise the temperature of one mole of it by one degree Celsius.

When using SI units, it can be calculated with the equation <math display="block">c_n = \frac Q {\Delta T}</math> where <math>c_n</math> refers to the molar heat capcity (in joules per Kelvin), <math>Q</math> to the heat supplied (in joules) and <math>\Delta T</math> (in Kelvin) to the temperature change in the substance.[1]

The molar heat capacity of a given substance can be found by heating the substance by releasing a known amount of energy into the substance and measuring the temperature change.

For example, a common school experiment to find the molar heat capacity of water involves heating a beaker of water with an immersion heater (that can display the heat released in joules on a display) and stirring the water, while checking the temperature at specific intervals.

For more accurate results, a bomb calorimeter can be used; these contain a chamber of fuel (in this case, a compound that will release heat when needed) inside a chamber of water, with the water chamber protected by heat-proof walls (to ensure minimal heat loss, which would affect the final heat capacity recorded).

References[change]

  1. "Molar Heat Capacity Definition and Examples". Thoughtco. Retrieved 7 August 2019.