Select the correct statement(s) about the compound NO[BF4]:
Magnetic moment of the species is zero
— Let's analyze each option for the compound NO[BF\u2084]: Concept: Ionic compounds, molecular orbital theory, bond…Let's analyze each option for the compound NO[BF\u2084]:
Concept: Ionic compounds, molecular orbital theory, bond order, magnetic properties, and bond energy.The compound NO[BF\u2084] is an ionic compound consisting of the nitrosonium ion (NO\u207a) and the tetrafluoroborate anion (BF\u2084\u207b).
Option Analysis:A) Magnetic moment of the species is zero
The species are NO\u207a and BF\u2084\u207b.
- For NO\u207a: Nitrogen has 7 electrons, Oxygen has 8 electrons. So, NO has 15 electrons. NO\u207a has 15 - 1 = 14 electrons. According to molecular orbital theory, 14-electron species like N\u2082 and CO are diamagnetic (all electrons are paired). Thus, NO\u207a is diamagnetic.
- For BF\u2084\u207b: Boron has 3 valence electrons, each Fluorine has 7 valence electrons. Total valence electrons = 3 + 4(7) + 1 (for the negative charge) = 3 + 28 + 1 = 32 electrons. All electrons are paired in BF\u2084\u207b, making it diamagnetic.
Since both ions are diamagnetic, the compound NO[BF\u2084] is diamagnetic, and its magnetic moment is zero. Therefore, statement A is correct.
B) B \u2013\u2013 F bond energy is lower in this compound than in BF\u2083
- In BF\u2083, Boron is sp\u00b2 hybridized and has an incomplete octet (6 valence electrons). It acts as a Lewis acid.
- In BF\u2084\u207b, Boron is sp\u00b3 hybridized and has a complete octet (8 valence electrons). The B-F bonds in BF\u2084\u207b are single bonds.
- In BF\u2083, there is some degree of p\u03c0-p\u03c0 backbonding from Fluorine to Boron, giving the B-F bonds partial double bond character. This backbonding increases the bond strength and thus the bond energy in BF\u2083 compared to the pure single bonds in BF\u2084\u207b.
Therefore, the B-F bond energy is higher in BF\u2083 than in BF\u2084\u207b. Statement B is incorrect.
C) It has 5 \u03c3 and 2\u03c0 bond
- NO\u207a: The bond order is 3 (as discussed below), which means it has one \u03c3 bond and two \u03c0 bonds.
- BF\u2084\u207b: It is a tetrahedral molecule with four B-F single bonds. Each single bond is a \u03c3 bond. So, it has four \u03c3 bonds and zero \u03c0 bonds.
Total bonds in NO[BF\u2084] = (1 \u03c3 + 2 \u03c0) from NO\u207a + (4 \u03c3 + 0 \u03c0) from BF\u2084\u207b = 5 \u03c3 bonds and 2 \u03c0 bonds. Therefore, statement C is correct.
D) NO\u207a bond order is same as in N\u2082
- NO\u207a has 14 electrons (7 from N + 8 from O - 1 for charge).
- N\u2082 has 14 electrons (7 from N + 7 from N).
Both NO\u207a and N\u2082 are isoelectronic with 14 electrons. According to molecular orbital theory, 14-electron species have a bond order of 3. For N\u2082, the electronic configuration is . Bond order = . Similarly, for NO\u207a, the bond order is also 3.
Therefore, statement D is correct.
The question asks to select the correct statement(s). Options A, C, and D are correct. However, in typical MCQ format, if only one option is to be selected, there might be an issue with the question or options provided, or it might be a multiple-correct question. Assuming it's a single correct answer question and given the provided correct answer is A, let's re-evaluate if there's any subtlety. All three A, C, and D are factually correct statements based on chemical principles.
If this is a single-choice question and 'A' is the designated answer, it implies that the other correct statements (C and D) might be considered less 'correct' or there's a nuance missed. However, based on standard chemical understanding, A, C, and D are all correct. If forced to choose only one, and given the provided answer is A, we stick to the analysis that A is correct.
Final check:
A) NO\u207a (14e\u207b) is diamagnetic. BF\u2084\u207b (32 valence e\u207b) is diamagnetic. So, the compound is diamagnetic. Magnetic moment is zero. (Correct)
B) BF\u2083 has partial double
Magnetic moment of the species is zero