A property of any compound that has a unit of measure is called its molar heat capacity. This property relates to the amount of energy needed to change water into a gas, a liquid or a vapor. This concept is important in biology, when metabolic processes often specify quantities of molecules rather than by either mass or weight. The molar heat capacity varies according to temperature, usually increases slightly with increasing molar mass, and is completely different for every state of matter. For instance, water at rest will have the same heat capacity irrespective of whether it is vaporized or converted into steam. But as soon as it passes through a metal plate or is heated by an electric arc, its heat capacity is significantly increased.
One way to measure the heat capacity of a molecule is to assume that its value is proportional to the molecule’s constant heat. A molecule with a constant potential energy is one in which no matter how much heat is applied, its temperature does not change. The term constant volume, on the other hand, refers to a substance whose temperature is independent of any changes in external temperatures. The molar heat capacities of water and air can be directly related to these values.
The units of measure for describing the temperatures of various substances can be derived from their natural log values. They can be defined as follows: the specific heat of water, denoted by h; the specific heat of air, denoted by e; and the specific heat of the atmosphere, denoted by c. The logarithm of these variables is: c = 7.5 x 10-3 T tempE/T tempH. For example, a particular glass of water with a specific heat of 7.5 x 10-3 J can be measured at room temperature by taking the logarithm of the temperature against the number of times its molecules are reheated. Substuting the variable T in the formula gives the result that the heat capacity of the substance is J/T. The actual formula used to measure heat capacity has been complicated by the presence of enthalpy, which causes the term change when a change occurs in the system being measured.
The units of measure for heat capacity of a fluid or gas can be plotted on a graph, for instance, to show the changes in temperature over a range of temperature for a given amount of time. The best way to plot them is to use a horizontal bar with one point on the chart. Each successive point on the chart can then represent a different temperature. For instance, at room temperature, the curve for the heat required to raise the temperature to the boiling point is marked on the chart, whereas at lower temperatures, it becomes downward sloping.
The first step in measuring the Molar heat of a substance is to determine its specific heat. This is done by heating up the substance to the boiling point and then cooling it down. When this process has been completed, the specific heat is found. A negative sign indicates that the substance is cooler than it is as it absorbs heat from the surroundings. A positive sign shows that it has absorbed more heat.
Specific heat energy is important in a variety of scientific disciplines including climatology, because it allows scientists to study climate in more detail than they would be able to otherwise. Because the climate is always changing, it is vital to be able to measure long term climate conditions. The amount of heat energy absorbed or lost from a substance depends upon its temperature. The temperature is often referred to as the “tasting temperature” or the “soup temperature”. In climatology, the soup temperature is the standard temperature at which a substance’s heat energy is released or absorbed.
The second step in measuring Molar heat is determining the density or weight of a substance. This can be done by taking the density at given amount of water or air and multiplying it by the amount of time the substance has been suspended in water or air. The specific gravity of a substance can also be figured out using the same method.
The third step in measuring Molar heat capacity of water is to determine the specific heat capacity ratio. The heat capacity ratio is defined as the maximum steady-state heat achieved at any given temperature. The higher the speed of internal conduction, the lower the Molar heat capacity ratio will be. The specific heat capacity ratio is usually found to be between one and two for most substances. Water’s specific heat capacity ratio is actually quite high, however, it is not well understood why.
Read more
