Q.60. Given below are two statements: Statement-I: The correct order in terms of atomic/ionic radii

Q: What is the correct answer for JEE Main Chemistry Q60?

The correct answer is B. Statement-I: The correct order in terms of atomic/ionic radii is Al > Mg > Mg$^{2+}$ > Al$^{3+}$. Atomic radii generally decrease across a period. So, Mg > Al. Ionic radii of cations are smaller than their parent atoms. Also, for isoelectronic species, higher positive charge means smaller size. Mg$^{2+}$ and Al$^{3+}$ are isoelectronic. Al$^{3+}$ has a higher nuclear charge than Mg$^{2+}$, so Al$^

Q: Q.60. Given below are two statements: Statement-I: The correct order in terms of atomic/ionic radii is Al > Mg > Mg > Al. Statement-II: The correct order in terms of the magnitude of electron gain…

The correct answer is B. Statement-I: The correct order in terms of atomic/ionic radii is Al > Mg > Mg$^{2+}$ > Al$^{3+}$. Atomic radii generally decrease across a period. So, Mg > Al. Ionic radii of cations are smaller than their parent atoms. Also, for isoelectronic species, higher positive charge means smaller size. Mg$^{2+}$ and Al$^{3+}$ are isoelectronic. Al$^{3+}$ has a higher nuclear charge than Mg$^{2+}$, so Al$^

Q: What are the options for this JEE Main Chemistry question?

A. Both Statement I and Statement II are false · B. Statement I is false but Statement II is true · C. Statement I is true but Statement II is false · D. Both Statement I and Statement II are true

Question

Q.60. Given below are two statements: Statement-I: The correct order in terms of atomic/ionic radii is Al > Mg > Mg > Al. Statement-II: The correct order in terms of the magnitude of electron gain enthalpy is Cl > Br > S > O. In the light of the above statements, choose the correct answer from the options given below:

FirstInTest · Accepted Answer

Statement-I: The correct order in terms of atomic/ionic radii is Al > Mg > Mg$^{2+}$ > Al$^{3+}$. Atomic radii generally decrease across a period. So, Mg > Al. Ionic radii of cations are smaller than their parent atoms. Also, for isoelectronic species, higher positive charge means smaller size. Mg$^{2+}$ and Al$^{3+}$ are isoelectronic. Al$^{3+}$ has a higher nuclear charge than Mg$^{2+}$, so Al$^{3+}$ < Mg$^{2+}$. Therefore, the correct order should be Mg > Al > Mg$^{2+}$ > Al$^{3+}$. The given order Al > Mg > Mg$^{2+}$ > Al$^{3+}$ is incorrect because Mg > Al. So, Statement-I is false. Statement-II: The correct order in terms of the magnitude of electron gain enthalpy is Cl > Br > S > O. Electron gain enthalpy generally becomes more negative across a period and less negative down a group. Chlorine has the highest (most negative) electron gain enthalpy among all elements. Sulfur is in the same period as Cl, and Oxygen is in the same group as S. Bromine is below Cl. The general trend is that halogens have more negative electron gain enthalpies than chalcogens. Also, electron gain enthalpy decreases down a group. So, Cl > Br. And S > O (due to smaller size of O leading to electron-electron repulsion). Comparing Cl, Br, S, O: Cl has the most negative electron gain enthalpy. Br is less negative than Cl. S is less negative than Cl and Br. O is generally less negative than S due to electron-electron repulsion in the small 2p orbital. So, the order of magnitude (most negative to least negative) is Cl > Br > S > O. This statement is true. Therefore, Statement-I is false but Statement-II is true.

Answer

Both Statement I and Statement II are false

Answer

Statement I is false but Statement II is true

Answer

Statement I is true but Statement II is false

Answer

Both Statement I and Statement II are true

Related Questionsin Chemistry

More from JEE Main

Browse Engineering Questions by Subject

Practice More JEE Main Questions