2014-09-18

basics of thermodynamics-part-8

When coal is burned in a power plant, only 3% of the energy in the coal is converted into light in a light bulb. What happens to the other 97% of the energy? Explain your answer using the laws of thermodynamics.
 
The majority of energy is released as heat. The first law of thermodynamics states that energy cannot be created or destroyed. The burning of coal simply converts the potential energy in coal to eclectic and heat energy. The second law of thermodynamics states that when energy is converted from one form to another, some of it is degraded into heat. This explains why no process requiring energy is 100% efficient.

What is Ideal gas?
It is defined as a gas having no forces of intermolecular attraction. These gases will follow the gas laws at all ranges of pressures and temperatures.

What is Charle’s law?
It states that if any gas is heated at constant pressure, its volume changes directly as its absolute temperature.

What is equation of state?
The relation between the independent properties such as pressure, specific volume and temperature for a pure substance is known as the equation of state.

What is Boyle’s law?
It states that volume of a given mass of a perfect gas varies inversely as the absolute pressure when temperature is constant.

What is Real gas?
It is defined, as a gas having the forces of attraction between molecules tends to be very small at reduced pressures and elevated temperatures.

What is Dalton’s law of partial pressure?
The pressure of a mixture of gases is equal to the sum of the partial pressures of the constituents. The partial pressure of each constituent is that pressure which the gas would expect if it occupied alone that volume occupied by the mixtures at the same temperatures. m = mA+mB+mC+……. = mi
mi = mass of the constituent.
P=PA+PB+PC+……. = Pi, Pi – the partial pressure of a constituent.
Explain Joule-Kelvin effect. What is inversion temperature?
When a gas (not ideal gas) is throttled, the temperature increases up to a point and then decreases. This is known as Joule Kelvin effect. The temperature at which the slope of a throttling curve in T-p diagram is zero is inversion temperature.

What is Avogardo’s Law?
The number of moles of any gas is proportional to the volume of gas at a given pressure and temperature.