1
JEE Main 2021 (Online) 25th July Morning Shift
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
Change Language
At 298.2 K the relationship between enthalpy of bond dissociation (in kJ mol$$-$$1) for hydrogen (EH) and its isotope, deuterium (ED), is best described by :
A
$${E_H} = {1 \over 2}{E_D}$$
B
$${E_H} = {E_D}$$
C
$${E_H} \simeq {E_D} - 7.5$$
D
$${E_H} = 2{E_D}$$
2
JEE Main 2021 (Online) 25th July Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
JEE Main 2021 (Online) 25th July Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 107 English
Consider the given reaction, the product 'X' is :
A
JEE Main 2021 (Online) 25th July Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 107 English Option 1
B
JEE Main 2021 (Online) 25th July Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 107 English Option 2
C
JEE Main 2021 (Online) 25th July Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 107 English Option 3
D
JEE Main 2021 (Online) 25th July Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 107 English Option 4
3
JEE Main 2021 (Online) 25th July Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
JEE Main 2021 (Online) 25th July Morning Shift Chemistry - Haloalkanes and Haloarenes Question 73 English
The given reaction can occur in the presence of :

(a) Bromine water

(b) Br2 in CS2, 273 K

(c) Br2/FeBr3

(d) Br2 in CHCl3, 273 K

Choose the correct answer from the options gien below :
A
(b) and (d) only
B
(a) and (c) only
C
(b), (c) and (d) only
D
(a), (b) and (d) only
4
JEE Main 2021 (Online) 25th July Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Given below are two statements, one is labelled as Assertion (A) and other is labelled as Reason (R).

Assertion (A) : Gabriel phthalimide synthesis cannot be used to prepare aromatic primary amines.

Reason (R) : Aryl halides do not undergo nucleophilic substitution reaction.

In the light of the above statements, choose the correct answer from the options given below :
A
Both (A) and (R) true but (R) is not the correct explanation of (A)
B
(A) is false but (R) is true.
C
Both (A) and (R) true and (R) is correct explanation of (A).
D
(A) is true but (R) is false.
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