The oxide that gives H2O2 most readily on treatment with H2O is :
A
PbO2
B
Na2O2
C
SnO2
D
BaO2 . 8H2O
Explanation
(a) PbO2 + 2H2O $$\to$$ Pb(OH)4
(b) Na2O2 + 2H2O $$\to$$ 2NaOH + H2O2
this reaction is possible at room temperature
(c) SnO2 + 2H2O $$\to$$ Sn(OH)4
(d) Acidified BaO2 . 8H2O gives H2O2 after evaporation.
2
JEE Main 2021 (Online) 27th August Morning Shift
MCQ (Single Correct Answer)
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
Explanation
The bond dissociation energy of D2 is greater than H2 and therefore D2 reacts slower than H2.
3
JEE Main 2021 (Online) 26th August Evening Shift
MCQ (Single Correct Answer)
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.
Explanation
D2O in used for the study of reaction mechanism. Rate of reaction for the cleavage of O-H bond > O-D bond.
4
JEE Main 2021 (Online) 26th August Morning Shift
MCQ (Single Correct Answer)
Which one of the following methods is most suitable for preparing deionized water?
A
Synthetic resin method
B
Clark's method
C
Calgon's method
D
Permutit method
Explanation
Pure demineralised (de-ionized) water free from all soluble mineral salts is obtained by passing water successively through a cation exchange (in the H+ form) and an anion exchange (in the OH$$-$$ form) resins.
Questions Asked from Hydrogen
On those following papers in MCQ (Single Correct Answer)
Number in Brackets after Paper Indicates No. of Questions
