Entropy Change in Irreversible Process

Q.

Pressure of 10 moles of an ideal gas is changed from 2 atm to 1 atm against constant external pressure without change in temperature. If surrounding temperature (300 K) and pressure (1 atm) always remains constant then calculate total entropy change ($\Delta S_{system}+\Delta S_{surrounding})$ for given process. [Given: ℓn2 = 0.70 amd R=8.0 J/mol/K]

1. 56 J/K

2. 14 J/K

3. 16 J/K

4. None of these

Q. For a sample of perfect gas when its preesure is changed isothermally from $p_{i}to{p}_f$, the entropy change is given by

1. $\Delta S=nRIn\left(\frac{p_f}{p_i}\right)$
2. $\Delta S=nRIn\left(\frac{p_i}{p_f}\right)$
3. $\Delta S=nRTIn\left(\frac{p_f}{p_i}\right)$
4. $\Delta S=RTIn\left(\frac{p_i}{p_f}\right)$

Q.

Two moles of ideal monoatomic gas was taken through isochoric heating from 100 K to 800 K. If the process is carried out irreversibly (one step) then $\Delta S_{system}+\Delta S_{surrounding}$ is

[Given : $ln2=0.7$ and $R=2cal/molK$]

1. 0

2. 3.675 cal/K
3. 7.35 cal/K
4. None of these

Q. Given that:
$S_{H_2}^{\circ }=131J{K}^{-1}mo{l}^{-1}{S}_{C{l}_2}^{\circ }=223J{K}^{-1}mo{l}^{-1}and{S}_{HCl}^{\circ }=187J{K}^{-1}mo{l}^{-1}$
The standard entropy change in formation of $1$ mole of $HCl\left(g\right)$ from $H_2\left(g\right)$ and $C{l}_2\left(g\right)$ will be:
(Given, reaction for formation of $HCl$ : $H_2+C{l}_2\to 2HCl$)

1. $20J{K}^{-1}$
2. $10J{K}^{-1}$
3. $187J{K}^{-1}$
4. $374J{K}^{-1}$

Q.

Two moles of ideal monoatomic gas was taken through isochoric heating from 100 K to 800 K. If the process is carried out irreversibly (one step) then $\Delta S_{system}+\Delta S_{surrounding}$ is

[Given : $ln2=0.7$ and $R=2cal/molK$]

1. 0

2. 3.675 cal/K
3. 7.35 cal/K
4. None of these

Q. The total entropy of a system and its surrounding increases, if the process is

1. reversible
2. irreversible
3. exothermic
4. endothermic

Q.

Pressure of 10 moles of an ideal gas is changed from 2 atm to 1 atm against constant external pressure without change in temperature. If surrounding temperature (300 K) and pressure (1 atm) always remains constant then calculate total entropy change ($\Delta S_{system}+\Delta S_{surrounding})$ for given process. [Given: ℓn2 = 0.70 amd R=8.0 J/mol/K]

1. 56 J/K

2. 14 J/K

3. 16 J/K

4. None of these

Q. Given that:
$S_{H_2}^{\circ }=131J{K}^{-1}mo{l}^{-1}{S}_{C{l}_2}^{\circ }=223J{K}^{-1}mo{l}^{-1}and{S}_{HCl}^{\circ }=187J{K}^{-1}mo{l}^{-1}$
The standard entropy change in formation of $1$ mole of $HCl\left(g\right)$ from $H_2\left(g\right)$ and $C{l}_2\left(g\right)$ will be:
(Given, reaction for formation of $HCl$ : $H_2+C{l}_2\to 2HCl$)

1. $20J{K}^{-1}$
2. $10J{K}^{-1}$
3. $187J{K}^{-1}$
4. $374J{K}^{-1}$

Q. For a sample of perfect gas when its preesure is changed isothermally from $p_{i}to{p}_f$, the entropy change is given by

1. $\Delta S=nRIn\left(\frac{p_f}{p_i}\right)$
2. $\Delta S=nRIn\left(\frac{p_i}{p_f}\right)$
3. $\Delta S=nRTIn\left(\frac{p_f}{p_i}\right)$
4. $\Delta S=RTIn\left(\frac{p_i}{p_f}\right)$

Q. Two moles of an ideal gas are expanded irreversibly and isothermally at ${37}^{\circ }\text{C}$ until the volume is doubled, and 3.41 kJ heat is absorbed from the surroundings.
$\Delta S_{total}\text{(system + surrounding)}$ is $(R=\frac{25}{3}\text{J/molK, ln 2=0.7, ln 3 = 1.1})$:

1. - 0.667 J/K
2. 0.667 J/K
3. 22.7 J/K
4. \N