Why a gas has two specific heats whereas a liquid and solid have only one Why?

A solid or a liquid when heated does not undergo any change in the volume or pressure. But in case of a gas, both the pressure and volume change on heating. Therefore, specific heat of a gas is defined either at constant volume or at constant pressure and hence a gas has two specific heats.

Why a gas has 2 specific heat?

A gas has more than one specific heats, whereas a liquid and solid have only one. But in case of a gas, both the pressure and volume change on heating. Therefore, specific heat of a gas is defined either at constant volume or at constant pressure and hence a gas has two specific heats.

Which has more specific heat solid liquid or gas?

liquid has a higher heat capacity than solid or gas and this is because liquid can absorb the most heat (translational and vibrational) but solids absorb only vibrational and gases absorb only translational.

WHY CAN 2 substances have different specific heat values?

Each substance will have a different mass, so when the amount of heat and the change in temperature are held constant, the only variable is the mass. Therefore, because mass is the only variable, so because substances have different masses, they will have different specific heats.

How many specific heats does a gas possess?

Solids and liquids have only one specific heat, while gases have two specific heats: In the case of solids and liquids, a small change in temperature causes a negligible change in the volume and pressure, hence the external work performed is negligible.

Which of the following has two specific heat?

From the above, it is clear that gas has two specific heats. Therefore option 2 is correct.

What is the specific heat of gas?

The specific heat of a gas at constant pressure is the amount of heat required to raise the temperature of one mole of a gas by unit temperature at constant pressure.

Why do liquids have the highest specific heat?

Water’s high heat capacity is a property caused by hydrogen bonding among water molecules. When the temperature of water decreases, the hydrogen bonds are formed and release a considerable amount of energy. Water has the highest specific heat capacity of any liquid.

Do solids have specific heat?

Also in case of solid, the values of Cp and Cv remains almost same, hence solid has only one specific heat. By definition,The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius.

What determines specific heat?

This quantity is known as the specific heat capacity (or simply, the specific heat), which is the heat capacity per unit mass of a material. Experiments show that the transferred heat depends on three factors: (1) The change in temperature, (2) the mass of the system, and (3) the substance and phase of the substance.

What causes specific heat?

Water’s high heat capacity is a property caused by hydrogen bonding among water molecules. Specific heat is defined as the amount of heat one gram of a substance must absorb or lose to change its temperature by one degree Celsius. For water, this amount is one calorie, or 4.184 Joules.

Why do solids have different specific heat values for gases?

But solids do not have a huge variation since their interatomic distance remains the same at both constant volume and constant pressure, and so do liquids at certain temperature and pressure. That’s why we use dual specific heat values for gases only.

How do we measure specific heat of gases?

For gases, the measurement can be affected by many state variables of the system such as temperature, pressure and volume of the system before and after the heat is added. Therefore, we use two methods to measure the specific heat of gases, which are at constant volume and constant pressure.

Why is specific heat at constant pressure greater than at constant volume?

Therefore, heat supplied at constant pressure is more than heat supplied at constant volume by an amount of heat which is used for doing external work. This explains why specific heat of a gas at constant pressure is greater than the specific heat at constant volume. i.e. C P > C V. Further by Mayer’s relation C P – C V = R.

Why do liquids have only 1 heat capacity?

Liquids are not compressible ( P has almost no effect on V) It is not entirely correct to say that liquids gave only 1 heat capacity. Actually they have both Cp and Cv, whose values are widely reported.