1
JEE Main 2019 (Online) 11th January Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
The standard reaction Gibbs energy for a chemical reaction at an absolute temperature T is given by $$\Delta $$rGo = A – BT

Where A and B are non-zero constants. Which of the following is TRUE about this reaction?
A
Exothermic if B < 0
B
Endothermic if A > 0
C
Exothermic if A > 0 and B < 0
D
Endothermic if A < 0 and B > 0
2
JEE Main 2019 (Online) 11th January Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
The reaction 2X $$ \to $$ B is a zeroth order reaction. If the initial concentration of X is 0.2 M, the half-life is 6 h. When the initial concentration of X is 0.5 M, the time required to reach its final concentration of 0.2 M will be:
A
18.0 h
B
9.0 h
C
7.2 h
D
12.0 h
3
JEE Main 2019 (Online) 11th January Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
The reaction, MgO(s) + C(s) $$ \to $$ Mg(s) + CO(g), for which $$\Delta $$rHo + 491.1 kJ mol–1 and $$\Delta $$rSo = 198.0 JK–1 mol–1, is not feasible at 298 K. Temperature above which reaciton will be feasible is :
A
2480.3 K
B
2040.5 K
C
2380.5 K
D
1890.0 K
4
JEE Main 2019 (Online) 11th January Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
K2Hgl4 is 40% ionised in aqueous solution. The value of its van't Hoff factor (i) is:
A
1.6
B
2.2
C
2.0
D
1.8

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