1
NEET 2016 Phase 2
+4
-1
For a sample of perfect gas when its pressure is changed isothermally from pi to pf, the entropy change is given by
A
$$\Delta S = nR\,\ln \left( {{{{p_f}} \over {{p_i}}}} \right)$$
B
$$\Delta S = nR\,\ln \left( {{{{p_i}} \over {{p_f}}}} \right)$$
C
$$\Delta S = nRT\,\ln \left( {{{{p_f}} \over {{p_i}}}} \right)$$
D
$$\Delta S = RT\,\ln \left( {{{{p_i}} \over {{p_f}}}} \right)$$
2
AIPMT 2015
+4
-1
The heat of combination of carbon to CO2 is $$-$$393.5 kJ/mol. The heat released upon formation of 35.2 g of CO2 from carbon and oxygen gas is
A
+ 315 kJ
B
$$-$$630 kJ
C
$$-$$ 3.15 kJ
D
$$-$$ 315 kJ
3
AIPMT 2014
+4
-1
Which of the following statements is correct for the spontaneous adsorption of a gas?
A
$$\Delta$$S is negative and, therefore $$\Delta$$H should be highly positive.
B
$$\Delta$$S is negative and therefore, $$\Delta$$H should be highly negative.
C
$$\Delta$$S is positive and therefore, $$\Delta$$H should be negative .
D
$$\Delta$$S is positive and therefore, $$\Delta$$H should also be highly positive.
4
AIPMT 2014
+4
-1
For the reaction, $${X_2}{O_{4\left( l \right)}}\,\, \to \,\,2X{O_{2(g)}}$$

$$\Delta$$U = 2.1 kcal, $$\Delta$$S = 20 cal K$$-$$1 at 300 K

Hence, G is
A
2.7 kcal
B
$$-$$ 2.7 kcal
C
9.3 kcal
D
$$-$$ 9.3 kcal
EXAM MAP
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