1
AIEEE 2008
+4
-1
Oxidising power of chlorine in aqueous solution can be determined by the parameters indicated below:
$${1 \over 2}C{l_2}(g)$$ $$\buildrel {{1 \over 2}{\Delta _{diss}}{H^\Theta }} \over \longrightarrow$$ $$Cl(g)$$ $$\buildrel {{\Delta _{eg}}{H^\Theta }} \over \longrightarrow$$ $$C{l^ - }(g)$$ $$\buildrel {{\Delta _{Hyd}}{H^\Theta }} \over \longrightarrow$$ $$C{l^ - }(aq)$$
(Using the data, $${\Delta _{diss}}H_{C{l_2}}^\Theta$$ = 240 kJ/mol, $${\Delta _{eg}}H_{Cl}^\Theta$$ = -349 kJ/mol, $${\Delta _{hyd}}H_{C{l^ - }}^\Theta$$ = - 381 kJ/mol) will be :
A
+152 kJ mol−1
B
−610 kJ mol−1
C
−850 kJ mol−1
D
+120 kJ mol−1
2
AIEEE 2008
+4
-1
Standard entropy of X2, Y2 and XY3 are 60, 40 and 50 JK−1 mol−1 , respectively. For the reaction,
$${1 \over 2} X_2$$ + $${3 \over 2} Y_2 \to$$ XY3, $$\Delta H$$ = -30 kJ, to be at equilibrium, the temperature will be :
A
1250 K
B
500 K
C
750 K
D
1000 K
3
AIEEE 2007
+4
-1
In conversion of lime-stone to lime,
CaCO3(s) $$\to$$ CaO(s) + CO2 (g) the vales of ∆H° and ∆S° are +179.1 kJ mol−1 and 160.2 J/K respectively at 298 K and 1 bar. Assuming that ∆H° do not change with temperature, temperature above which conversion of limestone to lime will be spontaneous is :
A
1008 K
B
1200
C
845 K
D
1118 K
4
AIEEE 2007
+4
-1
Identify the correct statement regarding a spontaneous process :
A
For a spontaneous process in an isolated system, the change in entropy is positive
B
Endothermic processes are never spontaneous
C
Exothermic processes are always spontaneous
D
Lowering of energy in the reaction process is the only criterion for spontaneity
EXAM MAP
Medical
NEET