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Multiple choice chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

Which of the following statement is correct regarding metal carbonyl?

  1. In ${Mn} _{2}{(CO)} _{10}$ bond order of $Mn-Mn$ is $0$
  2. In ${Fe} _{2}{(CO)} _{9}$ bond order of $Fe-Fe$ is $1$
  3. In $Ni{(CO)} _{4}$, all bond length are same
  4. $Fe{(CO)} _{5}$ is diamagnetic
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Fe(CO)5 is a 18-electron complex with a trigonal bipyramidal structure. All electrons are paired in the d-orbitals, making it diamagnetic.

Multiple choice chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

Which of the following does not have a metal-carbon bond.

  1. ${C} _{2}{H} _{5}MgBr$
  2. $K[Pt({C} _{2}{H} _{4}){Cl} _{2}]$
  3. $Ni{(CO)} _{4}$
  4. $Al{(O{C} _{2}{H} _{5})} _{3}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Al(OC2H5)3 is an aluminum alkoxide. It contains Al-O bonds, not Al-C bonds. The other options are organometallic compounds containing direct metal-carbon bonds.

Multiple choice chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

Which of the following is correct value of n in ${\text{Cr}}\left( {{\text{CO}}} \right){\text{n}}$

  1. 2

  2. 4

  3. 6

  4. Unpredictable
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

According to the 18-electron rule, chromium (atomic number 24) has 6 valence electrons, and each CO ligand contributes 2 electrons. To achieve a stable noble gas configuration of 18 electrons, chromium needs 6 carbonyl ligands, making the formula Cr(CO)6.

Multiple choice chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

Which of the following is correct?

  1. $H _{3}PO _{3}$ is dibasic and reducing
  2. $H _{3}PO _{3}$ is dibasic and non-reducing
  3. $H _{3}PO _{4}$ is tribasic and reducing
  4. $H _{3}PO _{3}$ is tribasic and non-reducing
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Phosphorous acid, H3PO3, has two P-OH bonds, making it dibasic. It also contains one P-H bond directly linked to hydrogen, which acts as a strong reducing agent.

Multiple choice chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

Which of the following organometallic compound

is $\sigma $ and $\pi $ bonded?

  1. $[Fe(\eta ^{5}-C _{5}H _{5}) _{2}]$
  2. $[PtCl _{3}(\eta ^{2}-C _{2}H _{4})]$
  3. $[Co(CO) _{5}NH _{3}]^{2+}$
  4. $Al(CH _{3}) _{3}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$[PtCl _{3}(\eta ^{2}-C _{2}H _{4})]$ and $[Fe(\eta ^{5}-C _{5}H _{5}) _{2}]$ are pi bonded organometallic compound.

$Al(CH _3) _3$ 
is sigma bonded organometallic compound.
$[Co(CO) _{5}NH _{3}]^{2+}$ is sigma and pi bonded organometallic compound.

Multiple choice chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

Which of the following organometallic compound is $\sigma$ and $\pi$ bonded -

  1. $[Fe(\eta^{5} - C _5H _5) _2]$
  2. $K[PtCl _3(\eta^{2} - C _2H _40]$
  3. $[Co(CO) _5NH _3]^{+2}$
  4. $Fe(CH _3) _3$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Option (C) is correct.
$[Co(CO) _5NH _3]^{+2}$ is $\sigma$ and $\pi$ bonded.
In this organometallic compound,bond between cobalt and $CO$ ligands have both $\sigma$ and $\pi$ character.$\sigma$- bond formation between metal and carbon of $CO$ takes place by overlap of filled bonding $\pi _{2p}$ of $CO$ with an empty metal $d$- orbital.
The 2nd overlap takes place between metal $d$- orbital with an empty antibonding pi orbital of the $CO$ resulting in additional $\pi$- bond between the metal and same $CO$ molecule.