Entropy and Second Law of Thermodynamics

Unit of entropy is:

$2 \mathrm{mol}$ of an ideal gas at  $27°\mathrm{C}$ temperature is expanded reversibly from $2 \mathrm{L}$ to $20 \mathrm{L}$. Find the entropy change. $\left(\mathrm{R}=2 \mathrm{cal}/\mathrm{mol} \mathrm{K}\right)$    

The adsorption of a gas at the boiling point of the gas follows the isotherm shown in the figure. Identify the correct thermodynamic properties at point $C.$

A heat engine absorbs heat ${\mathrm{Q}}_1$ at temperature ${\mathrm{T}}_1$ and heat ${\mathrm{Q}}_2$ at temperature ${\mathrm{T}}_2$. Work done by the engine is $\left({\mathrm{Q}}_1+{\mathrm{Q}}_2\right) \mathrm{J}$. This data

For which of the following processes, $∆\mathrm{S}$ is negative?

The molar heat capacity (${\mathrm{C}}_{\mathrm{p}}$) of ${\mathrm{CD}}_2\mathrm{O}$ is $10 \mathrm{cal}$ at $1000\mathrm{K}$. The change in entropy associated with cooling of $32\mathrm{g}$ of ${\mathrm{CD}}_2\mathrm{O}$ vapour from$1000\mathrm{K}-100\mathrm{K}$ at constant pressure will be : ($\mathrm{D}$ = deuterium, Atomic mass = $2$) 

The enthalpy of vaporization of water at $100°\mathrm{C}$ is $40.63 {\mathrm{kJmol}}^{-1}$. Its entropy of vaporization would be

The $\mathrm{SI}$ unit of $∆\mathrm{S}$ is 

What does entropy measure?

A container is divided into two compartments by a removable partition as shown below:

In the first compartment, ${\mathrm{n}}_1$ moles of ideal gas He is present in a volume ${\mathrm{V}}_1.$ In the second compartment, ${\mathrm{n}}_2$ moles of ideal gas $\mathrm{Ne}$ is present in a volume ${\mathrm{V}}_2.$ The temperature and pressure in both the compartments are $\mathrm{T}$ and $\mathrm{P},$ respectively. Assuming $\mathrm{R}$ is the gas constant, the total change in entropy upon removing the partition when the gases mix irreversibly is:

The change in entropy at equilibrium is 

The enthalpy of vaporization of water at $100°\mathrm{C}$ is $40.63 {\mathrm{kJmol}}^{-1}$. Its entropy of vaporization would be

$\mathrm{\Delta S}$ will be highest for

In which of the following processes, entropy of the system increases?

$\mathrm{I}$) Temperature of a crystalline solid is raised from $0 \mathrm{K}$ to $115 \mathrm{K}$.

$\mathrm{II}$) Liquid crystallizing to solid.

$\mathrm{III}$) $2{\mathrm{NaHCO}}_3 \left(\mathrm{s}\right)⟶{\mathrm{Na}}_2{\mathrm{CO}}_3 \left(\mathrm{s}\right)+{\mathrm{CO}}_2 \left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O} \left(\mathrm{g}\right)$

$\mathrm{IV}$) Vaporization of a liquid.

Among the following processes, for which process the change in entropy $\left(\mathrm{\Delta S}\right)$ is negative?

Elemental sulfur is formed by the reaction of  $\mathrm{ZnS}$ with oxygen at $300 \mathrm{K}$:

$2\mathrm{ZnS}\left(s\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\to 2\mathrm{ZnO}\left(s\right)+2 \mathrm{S}\left(\mathrm{s}\right)$

If $\mathrm{\Delta H}=-300 \mathrm{kJ}/\mathrm{mol}$ and $\mathrm{\Delta S}=-160{\mathrm{JK}}^{-1}$. Then ${\mathrm{\Delta S}}_{\mathrm{total}}$ is :

Elemental sulfur is formed by the reaction of $\mathrm{ZnS}$ with oxygen at $300 \mathrm{K}$

$2\mathrm{ZnS}\left(\mathrm{s}\right)+{\mathrm{O}}_2( \mathrm{g})\to 2\mathrm{ZnO}\left(\mathrm{s}\right)+2 \mathrm{S}( \mathrm{s})$

If $\mathrm{\Delta H}=-300 \mathrm{kJ}/\mathrm{mol}$ and $\mathrm{\Delta S}=-160{\mathrm{JK}}^{-1}$. Then ${\mathrm{\Delta S}}_{\mathrm{total} }$ is :