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Given below are two statements: one is labelled as Assertion A and the other is labeled as Reason R:
Assertion A: Hydrogen is the most abundant element in the Universe, but it is not the most abundant gas in the troposphere.
Reason R: Hydrogen is the lightest element.
In the light of the above statements, choose the correct answer from the options given below:

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:

Which one of the following metals forms interstitial hydride easily?

The correct statements about \( \displaystyle \text{H}_2\text{O}_2 \) are :
(A) used in the treatment of effluents.
(B) used as both oxidizing and reducing agent.
(C) the two hydroxyl groups lie in the same plane.
(D) miscible with water.
Choose the correct answer from the options given below:

Deuterium resembles hydrogen in properties but:

Which one of the following statements is incorrect ?

At \( 298.2 \, \text{K} \) the relationship between enthalpy of bond dissociation (in \( \text{kJ mol}^{-1} \)) for hydrogen \(( E_{\mathrm{H}} )\) and its isotope, deuterium, \(( E_{\mathrm{D}} )\), is best described by:

The product obtained from the electrolytic oxidation of acidified sulphate solutions, is:

The single largest industrial application of dihydrogen is:

Given below are two statements:
Statement I: The process of producing syn-gas is called gasification of coal.
Statement II: The composition of syn-gas is \( \mathrm{CO} + \mathrm{CO_2} + \mathrm{H_2} \) \( (1:1:1) \).
In the light of the above statements, choose the most appropriate answer from the options given below:

Hydrogen peroxide reacts with iodine in basic medium to give:

The INCORRECT statement(s) about heavy water is (are)
(A) used as a moderator in nuclear reactor
(B) obtained as a by-product in fertilizer industry
(C) used for the study of reaction mechanism
(D) has higher dielectric constant than water
Choose the correct answer from the options given below:

Isotope(s) of hydrogen which emits low energy \( \beta^{-0} \) particles \( t_{1/2} \) value \( > 12 \) years is/are:

Given below are two statements: One is labeled as Assertion A and the other is labelled as Reason R.
Assertion A: The dihedral angles in \( \mathrm{H_2O_2} \) in gaseous phase is \( 90.2^\circ \) and in solid phase is \( 111.5^\circ \).
Reason R: The change in dihedral angle in solid and gaseous phase is due to the difference in the intermolecular forces.
Choose the most appropriate answer from the options given below for A and R.

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JEE Main 2021 31st August Evening Shift

Which one of the following statements is incorrect ?