Q.53. Given below are two statements : Statement (I): The correct sequence of bond lengths in the fo

Q: What is the correct answer for this exam Chemistry Q53?

The correct answer is C. Let's analyze each statement: **Statement (I):** Bond length is inversely related to bond order. Higher bond order means shorter bond length. * O$_2^{2-}$ (peroxide ion): 18 electrons. Configuration: $(\sigma_{1s})^2 (\sigma_{1s}^*)^2 (\sigma_{2s})^2 (\sigma_{2s}^*)^2 (\sigma_{2p_z})^2 (\pi_{2p_x})^2 (\pi_{2p_y})^2 (\pi_{2p_x}^*)^2 (\pi_{2p_y}^*)^2$. Bond order = $\frac{1}{2}(10-8) = 1$. (Single

Q: Q.53. Given below are two statements : Statement (I): The correct sequence of bond lengths in the following species is : O < O < O Statement (II): The correct sequence of number of unpaired electrons…

The correct answer is C. Let's analyze each statement: **Statement (I):** Bond length is inversely related to bond order. Higher bond order means shorter bond length. * O$_2^{2-}$ (peroxide ion): 18 electrons. Configuration: $(\sigma_{1s})^2 (\sigma_{1s}^*)^2 (\sigma_{2s})^2 (\sigma_{2s}^*)^2 (\sigma_{2p_z})^2 (\pi_{2p_x})^2 (\pi_{2p_y})^2 (\pi_{2p_x}^*)^2 (\pi_{2p_y}^*)^2$. Bond order = $\frac{1}{2}(10-8) = 1$. (Single

Q: What are the options for this this exam Chemistry question?

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

Question

Q.53. Given below are two statements : Statement (I): The correct sequence of bond lengths in the following species is : O < O < O Statement (II): The correct sequence of number of unpaired electrons in the following species is : O > O > O > O In the light of the above statements, choose the correct answer from the options given below :

FirstInTest · Accepted Answer

Let's analyze each statement: **Statement (I):** Bond length is inversely related to bond order. Higher bond order means shorter bond length. * O$_2^{2-}$ (peroxide ion): 18 electrons. Configuration: $(\sigma_{1s})^2 (\sigma_{1s}^*)^2 (\sigma_{2s})^2 (\sigma_{2s}^*)^2 (\sigma_{2p_z})^2 (\pi_{2p_x})^2 (\pi_{2p_y})^2 (\pi_{2p_x}^*)^2 (\pi_{2p_y}^*)^2$. Bond order = $\frac{1}{2}(10-8) = 1$. (Single bond) * O$_2^{-}$ (superoxide ion): 17 electrons. Configuration: $(\sigma_{1s})^2 (\sigma_{1s}^*)^2 (\sigma_{2s})^2 (\sigma_{2s}^*)^2 (\sigma_{2p_z})^2 (\pi_{2p_x})^2 (\pi_{2p_y})^2 (\pi_{2p_x}^*)^2 (\pi_{2p_y}^*)^1$. Bond order = $\frac{1}{2}(10-7) = 1.5$. (One and a half bond) * O$_2$ (oxygen molecule): 16 electrons. Configuration: $(\sigma_{1s})^2 (\sigma_{1s}^*)^2 (\sigma_{2s})^2 (\sigma_{2s}^*)^2 (\sigma_{2p_z})^2 (\pi_{2p_x})^2 (\pi_{2p_y})^2 (\pi_{2p_x}^*)^1 (\pi_{2p_y}^*)^1$. Bond order = $\frac{1}{2}(10-6) = 2$. (Double bond) So, the bond orders are O$_2^{2-}$ (1) < O$_2^{-}$ (1.5) < O$_2$ (2). Therefore, the bond lengths will be in the order O$_2^{2-}$ > O$_2^{-}$ > O$_2$. Statement (I) says O$_2^{2-}$ < O$_2^{-}$ < O$_2$, which is incorrect. **Statement (II):** Number of unpaired electrons: * O$_2$: 2 unpaired electrons (in $\pi_{2p}^*$ orbitals). * O$_2^{+}$ (dioxygenyl ion): 15 electrons. Configuration: $(\sigma_{1s})^2 (\sigma_{1s}^*)^2 (\sigma_{2s})^2 (\sigma_{2s}^*)^2 (\sigma_{2p_z})^2 (\pi_{2p_x})^2 (\pi_{2p_y})^2 (\pi_{2p_x}^*)^1$. 1 unpaired electron. * O$_2^{-}$: 1 unpaired electron (in $\pi_{2p}^*$ orbital). * O$_2^{2-}$: 0 unpaired electrons (all electrons paired). So, the correct sequence of unpaired electrons is O$_2$ (2) > O$_2^{+}$ (1) = O$_2^{-}$ (1) > O$_2^{2-}$ (0). Statement (II) says O$_2$ > O$_2^{+}$ > O$_2^{-}$ > O$_2^{2-}$, which is correct. Therefore, Statement (I) is false but Statement (II) is true.

Answer

Both Statement I and Statement II are true

Answer

Both Statement I and Statement II are false

Answer

Statement I is true but Statement II is false

Answer

Statement I is false but Statement II is true

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