Chemical Engineering Thermodynamics - Study Mode

[#381] Pick out the wrong statement pertaining to the decomposition of PCl 5 represented by, PCl 5 ⇋ PCl 3 + Cl 2 . Degree of dissociation of PCl 5 will
Correct Answer

(D) None of these

Explanation

Solution: By Le Chatelier's principle we can say that the dissociation of $$PC{l_5}$$ xa0is increased by decrease of number of moles of the products or by decreasing the pressure.

[#382] A gas mixture of three components is brought in contact with a dispersion of an organic phase in water. The degree of freedom of the system are
Correct Answer

(B) 3

[#383] The compressibility factor of a gas is given by (where, V 1 = actual volume of the gas V 2 = gas volume predicted by ideal gas law)
Correct Answer

(A) $$frac{{{{ ext{V}}_1}}}{{{{ ext{V}}_2}}}$$

Explanation

Solution: The compressibility factor is given by $$Z = frac{{P{V_1}}}{{RT}}.$$ xa0 If at the same temperature and pressure if the same gas exists as ideal gas than we can write: [x08egin{array}{l}
Z = 1 = frac{{P{V_2}}}{{RT}} Rightarrow frac{{RT}}{P} = {V_2}\
{
m{So, }},,Z = frac{{{V_1}}}{{{V_2}}}.
end{array}]

[#384] Air enters an adiabatic compressor at 300 K. The exit temperature for a compression ratio of 3, assuming air to be an ideal gas $$left( {gamma = frac{{{{ ext{C}}_{ ext{p}}}}}{{{{ ext{C}}_{ ext{v}}}}} = frac{7}{5}}
ight)$$ xa0 and the process to be reversible, is
Correct Answer

(A) $$300left( {{3^{frac{2}{7}}}} ight)$$

Explanation

Solution: We know for an ideal gas at adiabatic conditions [x08egin{array}{l}
T{V^{gamma - 1}} = {
m{CONSTANT}}\
Rightarrow T{left( {frac{{RT}}{P}}
ight)^{gamma - 1}} = {
m{CONSTANT}}\
Rightarrow T{P^{frac{{1 - gamma }}{gamma }}} = {
m{CONSTANT}}\
{
m{So, }},frac{{{T_2}}}{{{T_1}}} = {left( {frac{{{P_2}}}{{{P_1}}}}
ight)^{frac{{gamma - 1}}{gamma }}}
end{array}] $$ Rightarrow $$ xa0given compression ratio $$frac{{{P_2}}}{{{P_1}}} = 3{ ext{ and }}gamma = frac{7}{5}$$ $${ ext{So, }}{T_2} = 300{left( 3
ight)^{frac{2}{7}}}.$$

[#385] As the temperature is lowered towards the absolute zero, the value of the quantity $$left( {frac{{partial Delta { ext{F}}}}{{partial { ext{T}}}}}
ight)$$ xa0approaches
Correct Answer

(A) Zero