MyRank: Different Types Of Thermodynamic Process At A Glance

Sunday, May 24, 2015

Different Types Of Thermodynamic Process At A Glance

S.No.	Change or name of the process	Isobaric	Isochromic	Isothermal	Adiabatic
1.	Definition	P=Constant	V=Constant	T=Constant	a) Q=Constant b) Entropy S = Constant
2.	dQ	1. For solids dQ = mc_pdT For gases nc_vDt 2. For change in state dQ = mL	1. For solids dQ = mc_vdT For gases nc_vdT	dQ = dW	Zero
3.	dU	1. dQ-pdV 2. dQ-nRdT	dQ	Zero	-dW
4.	dW	1. PdV 2. nRdT	Zero	$2.303nRt\log \frac{v_2}{v_1}$ $2.303p_1v_1\log \frac{v_2}{v_1}$ $2.303p_1v_1\log \frac{p_1}{p_2}$	$\frac{R(T_2-T_1)}{1-\gamma}$ $\frac{(P_2V_2-P_1V_1)}{1-\gamma}$
5.	Equation of state	$\frac{V}{T}= \text{constant}$ $\frac{V_1}{T_1} = \frac{V_2}{T_2}$	$\frac{P}{T} = \text{constant}$ $\frac{P_1}{T_1} = \frac{P_2}{T_2}$	$PV = \text{constant}$ $P_1V_1 = P_2V_2$	PV^γ=constant TV^γ-1=constant P^1-γT^γ=constant
6.	Slope of p-v curve	Zero	$\infty$	$-\frac{p}{v}$	$-\frac{\gamma p}{v}$
7.	Law	Charle's law	Gay-lussac's law	Boyle's law	Poisson's law
8.	Form of First laws	dQ=dU+dW =nc_pdT+PdV	dQ=dU=nc_vdT	dQ=dW=dV	-dU=dW
9.	Bulk modulus	Zero	Infinity	-p	-γp
10.	Result of maximum work	Maximum	Zero	Less from isobaric process but greater form adiabatic process	Minimum but not zero

Example :

A cylinder with a movable piston contains 3 moles of hydrogen at standard temperature and pressure. The walls of the cylinder are made of a heat insulator, and the piston is insulated by having a pile of sand on it. By what factor does the pressure of the gas increase if the gas is compressed to half its original volume?

Ans: As no heat is allowed to be exchanged, the process is adiabatic.

$\therefore P_2V_2^{\gamma} = P_1V_1^{\gamma} \,\, (or) \,\, \frac{P_2}{P_1} = \left( \frac{V_1}{V_2} \right )$