Table of Contents
Introduction:
Solids and liquids have only one specific heat, whereas gases have two: A small change in temperature causes a negligible change in volume and pressure in solids and liquids, so the external work performed is negligible. In such cases, the entire amount of heat supplied to the solid or liquid is used to raise the temperature. As a result, there is only one specific heat value for solids and liquids.
When gases are heated, even small changes in temperature cause significant changes in both volume and pressure. As a result, the specific heat of a gas can range between 0 and . As a result, in order to fix the values of a gas’s specific heat, either the volume or the pressure must be kept constant. As a result, two specific heats of gases must be defined. Specific heat at constant pressure and specific heat at constant volume are two examples.
In this article, we will look at the concept of specific heat capacities, also known as specific heats of gases. A gas’s specific heat at constant pressure and volume are specific constants and parameters that define many of its properties. The specific heat formula and the specific heat capacity formula will be covered in this section. The specific heat is the amount of heat required per unit mass to raise the temperature by one degree Celsius. The relationship between heat and temperature change is usually communicated in the structure that appears beneath where c is specific heat.
Overview:
At constant pressure, the specific heat of a gas is the amount of heat required to raise the temperature of one mole of a gas by unit temperature. The specific heat of a gas at constant volume, on the other hand, is the amount of heat required to raise the temperature of one mole of the gas by unit temperature at constant volume.
When heat is applied to a gas at constant pressure, it absorbs the heat and two things happen. The gas uses some of the thermal energy (heat) to increase its internal energy. This internal energy also represents the gas’s temperature change. The remainder of the heat is used by the gas to perform mechanical work (the gas expands). Mechanical work done by a gas is defined as the product of the gas’s pressure and volume change.
At constant pressure, the specific heat of a gas is the amount of heat required to raise the temperature of one mole of a gas by unit temperature. The specific heat of a gas at constant volume, on the other hand, is the amount of heat required to raise the temperature of one mole of the gas by unit temperature at constant volume. As a result, because less heat is required to achieve the same temperature rise in a constant volume process than in a constant pressure process because no heat is wasted for mechanical work, the specific heat of a gas at constant volume is less than the specific heat of a gas at constant pressure.
Specific Heat Explanation:
The amount of heat required to raise the temperature of one gram of a substance by one degree Celsius. Specific heat is usually measured in calories or joules per gram per Celsius degree. Water, for example, has a specific heat of 1 calorie (or 4.186 joules) per gram per Celsius degree. In the 18th century, the Scottish scientist Joseph Black noticed that equal masses of different substances required different amounts of heat to raise them through the same temperature interval, and he founded the concept of specific heat on this observation. The French physicists Pierre-Louis Dulong and Alexis-Thérèse Petit demonstrated in the early nineteenth century that measurements of specific heats of substances allow calculation of their atomic weights (see Dulong-Petit law). When two materials, each at a different temperature, come into contact with one another, heat always flows from the warmer material into the colder material until both reach the same temperature. The heat gained by the initially colder material must equal the heat lost by the initially warmer material, according to the law of conservation of energy.
A substance’s specific heat capacity (symbol c p) is the heat capacity of a sample of the substance divided by its mass. Specific heat is also known as massic heat capacity at times. Informally, it is the amount of heat that must be added to one unit of mass of the substance to cause a temperature increase of one unit. Specific heat capacity is measured in SI units of joule per kelvin per kilogram J kg-1 K-1.
Specific heat capacities of gases:
Heat capacity (Specific) of gases is defined as the amount of heat required to raise the temperature of one gram of gas by one degree Celsius per mole of gas and is also known as molar heat capacity or simply heat capacity. In physics or chemistry, the heat capacity equation expressed at constant pressure (C p), volume (C v ), and an energy unit is usually used to calculate it.
The calculation of C p or C v is affected by pressure and volume, particularly in the case of gas properties. As a result, the observed quantity in the two operations would differ. As a result, the pressure and volume conditions must be specified when measuring heat capacity.
Specific Heat Capacity Formula:
The heat energy required to change the temperature of one unit mass of a constant volume substance by one degree Celsius is referred to as specific heat. A substance’s specific heat capacity is the amount of energy required to change the temperature by 1 unit of material of 1 kg mass. J/Kg is the SI unit for specific heat and specific heat capacity.
The thermal capacity or heat capacity of matter or substance is a physical property of matter or substance. This property is defined as the amount of heat applied to a given mass of a material in order to produce a change in unit temperature. The SI unit for thermal capacity is Joule per Kelvin (J/Kg). Aside from that, the heat capacity formula, also known as the thermal capacity formula, is as follows:
C=lim T→0 ∆Q/∆T
Here,
Delta Q is the amount of heat that must be applied to the object of mass “M” in order to raise its temperature by delta T.
The specific heat capacity formula is as follows:
Q=m c∆t
c=Q /m∆t
Here,
Q = the heat energy.
m = mass in kilogram
c = the specific heat capacity, and
The temperature change in Kelvin is denoted by t.
In addition, the temperature change is given by:
∆T=( T f -Ti)
Where T f denotes the final temperature and Ti denotes the starting temperature in K.
Specific Heat Capacity Unit:
Specific heat capacity is measured in joules per kelvin per kilogram (J/K)/kg,J/(kg·K),J kg-1 K-1, etc. . Because a temperature increase of one degree Celsius equals a kelvin increase, the unit of measurement is joule per degree Celsius per kilogram J kg-1 C-1. The gram is sometimes used instead of the kilogram as a unit of mass: :1 J g-1 K-1=0.001 J kg-1 K-1. As a result, the SI unit J kg-1 K-1 is equivalent to m 2·K-1·s-2 (metre squared per second squared per kelvin).
S.I. unit of specific heat capacity is J kg-1 K-1.
Also read: Change of state
Frequently Asked Questions (FAQs) :
Question 1:What is the significance of the Specific Heat Capacity Formula?
Answer: The specific heat formula is used to calculate the specific heat of any given material if any of the parameters, such as mass, heat gained, or temperature difference, are given. It is measured in Joule/Kg Kelvin, which is abbreviated as J/Kg K. The specific heat capacity formula calculates a material’s specific heat capacity in Joule/Kilogram-Kelvin (abbreviated as J/Kg. K). The following are the implications of specific heat capacity: It is the amount of heat energy required to raise the temperature of one kilogram of a substance by one degree Celsius. As a result, it provides an important indication of how much energy will be required to heat/cool a given mass by a given amount.
Question 2:What is the liquid’s specific heat?
Answer: The specific heat capacity (Cp) at room temperature is approximately 4.2 J/g°C. This means that it takes 4.2 joules of energy to raise the temperature of one gram of water by one degree Celsius.
