1
JEE Main 2019 (Online) 11th January Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
The number of bridging CO ligand(s) and Co-Co bond(s) in Co2(CO)8, respectively are :
A
2 and 0
B
0 and 2
C
4 and 0
D
2 and 1
2
JEE Main 2019 (Online) 11th January Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
$$\underline A \,\,\buildrel {4KOH,{O_2}} \over \longrightarrow \,\,\mathop {2\underline B }\limits_{\left( {Green} \right)} \,\, + \,\,2{H_2}O$$

$$3\underline B \,\,\buildrel {4HCl} \over \longrightarrow \,\,\mathop {2\underline C }\limits_{\left( {Purple} \right)} \,\, + \,\,Mn{O_2} + 2{H_2}O$$

$$2\underline C \,\,\buildrel {{H_2}O.KI} \over \longrightarrow \,\,\mathop {2\underline A }\limits_{\left( {Purple} \right)} \,\, + \,\,2KOH\,\, + \,\,\underline D $$

In the above sequence of reactions, $${\underline A }$$ and $${\underline D }$$, respectively, are :
A
Kl and KMnO4
B
Kl and K2MnO4
C
KlO3 and MnO2
D
MnO2 and KlO3
3
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
4
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

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