1
JEE Main 2020 (Online) 7th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
The electron gain enthalpy (in KJ/mol) of fluorine, chlorine, bromine and iodine, respectively are:
A
-296, -325, -333 and -349
B
349, -333, -325 and -296
C
-333, -349, -325 and -296
D
-333, -325, -349 and -296
2
JEE Main 2020 (Online) 7th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
Amongst the following statements, that which was not proposed by Dalton was :
A
Matter consists of indivisible atoms all the atoms of a given element have.
B
Chemical reactions involve reorganization of atoms. These are neither created not destroyed in a chemical reaction.
C
When gases combine or reproduced in a chemical reactionn they do so in a simple ratio by volume provided all gases are the same T & P.
D
Identical properties including identical mass. Atoms of differemt element differ in mass.
3
JEE Main 2020 (Online) 7th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
Consider the following reaction :

$${\left( {C{H_3}} \right)_3}CCH\left( {OH} \right)C{H_3}\buildrel {conc.\,\,\,{H_2}S{O_4}} \over \longrightarrow $$

$${\left( {C{H_3}} \right)_2}CHCH\left( {Br} \right)C{H_3}\buildrel {alc.\,\,KOH} \over \longrightarrow $$

$${\left( {C{H_3}} \right)_2}{\rm{ }}CHCH\left( {Br} \right)C{H_3}\buildrel {{{(C{H_3})}_3}{O^\Theta }{K^ \oplus }} \over \longrightarrow $$

$${\left( {C{H_3}} \right)_2}\mathop C\limits_{\mathop |\limits_{OH} } - C{H_2} - CHO\buildrel \Delta \over \longrightarrow $$

Which of these reaction(s) will not produce Saytzeff product ?
A
(d) only
B
(b) and (d)
C
(a), (c) and (d)
D
(c) only
4
JEE Main 2020 (Online) 7th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
Oxidation number of potassium in K2O. K2O2 and KO2 respectively is :
A
+1, +2 and + 4
B
+1, +1 and + 1
C
+2, +1 and $$ + {1 \over 2}$$
D
+1, +4, and +2

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