What is the specific heat capacity?
The specific heat capacity is defined as the quantity of heat (J) absorbed per unit mass (kg) of the object when its temperature increases by 1 K (or 1 °C), and its units are J/(kg K) or J/(kg °C).
Specific heat values may be determined in the following way: when two different objects are placed in contact with each other, we know that heat usually flows from the hotter object into the cooler object till each of them obtains an equal temperature. From the regulation of conservation of energy, the heat lost by the warmer object is equal to the heat gained by the cooler object.
We recognize that once the heat energy is absorbed by a substance, its temperature increases. If an equal amount of heat is given to similar masses of various materials, it is seen that the rise of temperature is different for the material each other. This is because materials have exceptional heat capacities. So the heat potential of a substance is the amount of warmth required to elevate the temperature of the complete substance via means of one degree. If the mass of the substance is team spirit then the warmth potential is known as Specific warmth potential or the precise warmth.
Equations
The following is the equation for specific heat :
Q=mc∆T
Where;
Q=heat energy
M= mass
C=specific heat capacity
∆T= change in temperature
Eg: if the specific heat of Au is 129J/kg. How much ch heat energy is required to change the temperature of 100g of Au by 60.0K.
Solution: here m=100g
c=129
T=60
So,
Q=mc∆T
=(0.100)kg*129*60
Q= 774J
Units
The standard unit of specific heat capacity is given by joule per kelvin per kilogram.
J. k^-1.kg^-1.
For example, the heat required to elevate the temperature of one kg of water via means of 1 K is 4184 joules, so the particular warmness capability of water is 4184 J⋅kg−1⋅K−1.
In chemistry, heat portions have been often measured in calories. Confusingly, devices with that name, denoted "cal" or "Cal", had been normally used to diploma portions of heat:
They were differentiated as "small calorie",(gram calorie) and "grand calorie"(kilogram calorie).
While those gadgets are nevertheless utilized in a few contexts (which includes kilogram calorie in nutrition), their use is now deprecated in technical and clinical fields.
Specific heat capacities of elements
Specific heat of different elements:
Specific heat capacity of liquid/solid elements:
Aluminum 0.897
Paraffin 2.100
Copper 0.384
Rubber 2.010
Ethanol 2.940
Salt. 0.880
Gold 0.129
Silver 0.236
Graphite 0.838
Tin 0.220
Specific heat of some gasses:
Air 1.005
Ammonia 2.191
Argon 0.5234
Butane 1.68
Carbon dioxide0.845
Carbon monoxide1.041
Physical basis
The temperature of a substance is not the same as the average kinetic energy of its constituent particles. The temperature of a sample of gas reflects the average kinetic energy of its constituent particles relative to the center of mass. The molecules are in constant motion and do not have a common speed (unlike for example with marbles in a box). When the gas molecules collide, the energy they gain or lose will not necessarily go into raising their temperature. However, if all the energy provided to a sample goes into raising its temperature, then this is proof of what's called the equipartition theorem.
The heating capacity of the monatomic gasses exhibits a peculiar minimum at the temperature of 300 kelvin. The reason for this strange behavior was not understood until 1965 when Lars Onsager predicted this minimum in an attempt to explain how transpiration is possible between two surfaces that are in thermal equilibrium with each other (see thermal boundary layer), and is due to the quantum mechanical exchange of phonons between the gas molecules.
The ability to store heat energy other than in its kinetic energy is one aspect of what makes polyatomic molecules useful for life. For example, hydrocarbon fuels, such as gasoline and methane, are chains of carbon atoms that contain a lot of covalent bonds between atoms. When a hydrocarbon fuel is burned, the covalent bonds break apart when energy from the combustion reaction is used to break them apart.
Specific Heat at Constant Pressure or Volume
The specific heat of a gas at the same volume is defined as the quantity of heat required to increase the temperature of the unit mass of the gas by 1 degree when it is heated at a constant volume. This gas property calculator allows you to measure, in mAh, the specific heat of a gas at constant volume (cv) given its temperature in degrees Celsius (°C), pressure in bars, and its molar mass in grams per mole (g/mol).
Specific heat capacity of gasses refers to the specific heat capacity per unit amount of a gas, rather than that per unit mass. This means that the specific heat capacity can be defined as the quantity of heat required by a given mass of gas to increase the temperature by 1 degree while remaining at constant pressure.
To understand how mpg is calculated, we must first refer to the equation of conservation of mass. This law states that matter can neither be created nor destroyed, but can change form. The applied science of this law is that a mass of gas cannot be heated without providing a certain amount of extra energy. This heat comes from the environment, and for every pound of gas, about 1000 BTU (British thermal units) are needed to raise the temp by 1 deg F. Of course, this equivalence assumes that the pressure exerted upon the environment is constant throughout the process.
Conversion of specific heat to molar heat
The amount of energy needed to raise one mole of a substance by one Melvin is known as molar heat capacity. Simply put, it is the amount of energy needed to heat one mole of a substance one degree Kelvin. The molar heat capacity of a chemical substance is often represented by the letter C.
To calculate the molar heat of a substance:
1. We have to find the heat capacity of the substance, by using the formula;
C=Q/∆T
2. The. We find the specific heat capacity of the substance by dividing the heat capacity by mass,i.e,.c=C/m
3. The molar heat capacity of a substance is used to determine the amount of heat energy required to raise the temperature of a sample. In the formula for molar heat capacity (cm= C/n), you will find the term ‘n’, representing the number of moles in the sample. To find the number of moles, divide the quantity of the sample by its molar mass.
Number of moles=weight of the sample (grams)/molar mass (grams/mol)
n=m/M
You have the formula for molar heat capacity, so substitute its value into the formula presenting it. You will then be able to calculate its molar heat capacity. However, this formula relies on an equation that requires you to have the molar mass (M) of your sample. If you have trouble finding these values, you can also use a conversion table to convert the specific heat (c) of your sample to its molar mass. Then take that number and multiply it by your total number of moles (n).
Application
Materials having a small specific heat capacity can be quickly heated up, it also experiences a big temperature change even though only a small amount of heat is supplied. They are very useful as a material in cooking instruments such as frying pans, pots, kettles, and so on because they can be quickly heated up even when a small amount of heat is supplied. Sensitive thermometers also must be made from materials with small specific heat capacity so that they can detect and show a change of temperature rapidly and accurately.
A high specific heat capacity is an indicator of how much heat energy a substance can store before its temperature changes very quickly. The higher the specific heat capacity, the better the material is at absorbing heat and not letting it dissipate or escape. Kettle Handlers, Insulators, and Oven Covers are all instruments that serve specific functions in the kitchen. Made of substances with a high specific heat capacity, a small amount of heat will cause only a small temperature change, they don't get hot too fast. They are available in stainless steel as well as other materials.
Conclusion
In this, we study the specific heat capacity and its equation. The specific heat capacity is defined as the quantity of heat absorbed per unit mass of the object when its temperature increases by 1 K and its units are J/(kg K). The equation is Q=mc∆T. The unit stand for specific heat capacity is given by joule per kelvin per kilogram. After that, we see some elements of specific heat and learn about the calculation of conversion of specific heat to molar heat.