1
JEE Main 2021 (Online) 31st August Evening Shift
+4
-1
Which one of the following statements is incorrect?
A
Atomic hydrogen is produced when H2 molecules at a high temperature are irradiated with UV radiation.
B
At around 2000 K, the dissociation of dihydrogen into its atoms is nearly 8.1%
C
Bond dissociation enthalpy of H2 is highest among diatomic gaseous molecules which contain a single bond.
D
Dihydrogen is produced on reacting zinc with HCl as well as NaOH(aq).
2
JEE Main 2021 (Online) 27th August Evening Shift
+4
-1
The oxide that gives H2O2 most readily on treatment with H2O is :
A
PbO2
B
Na2O2
C
SnO2
D
BaO2 . 8H2O
3
JEE Main 2021 (Online) 27th August Morning Shift
+4
-1
Deuterium resembles hydrogen in properties but :
A
reacts slower than hydrogen
B
reacts vigorously than hydrogen
C
reacts just as hydrogen
D
emits $$\beta$$+ particles
4
JEE Main 2021 (Online) 26th August Evening Shift
+4
-1
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : Heavy water is used for the study of reaction mechanism.

Reason (R) : The rate of reaction for the cleavage of O - H bond is slower than that of O - D bond.

Choose the most appropriate answer from the options given below :
A
Both (A) and (R) are true but (R) is not the true explanation of (A).
B
Both (A) and (R) are true and (R) is the true explanation of (A).
C
(A) is false but (R) is true.
D
(A) is true but (R) is false.
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