Tag: metal carbonyls

Questions Related to metal carbonyls

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

Chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal.

$C _2H _5MgBr$ is a $\sigma$-bonded complexes.
$K[Pt(C _2H _4)Cl _3]$ contains a bond between carbon and potassium which is a metal.
$Ni(CO) _4$ also contains metal-carbon bond as it is itself a metal carbonyl.

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

Which of the following statement(s) is/are true?

  1. In metal carbonyl complexes $d _{C-O}$ increases compared to that in CO molecule
  2. The pair of compounds $[Cr(H _2O) _6]Cl _3$ and $[CrCl _3(H _2O) _3]\cdot 3H _2O$ show hydrate isomerism.
  3. $d _{z^2}$ orbital of central metal atom/ion is used in $dsp^2$ hybridisation.
  4. Facid and Meridional isomers associated with $[Ma _3b _3]^{n\pm}$ type complex compound, both are optically inactive.
Reveal answer Fill a bubble to check yourself
A,D Correct answer
Explanation

(A) Metal carbonyls involve synergic bonding $(M\underset {\sigma}{\overset {\pi}\rightleftharpoons } L)$. Filled metal d orbital overlaps with antibonding pi orbital of CO. Thus the bond order and bond length in CO decreases.
Thus option A is correct.
(B) $[CrCl _3(H _2O) _3]\cdot 3H _2O$ is not a hydrate isomer of $[Cr(H _2O) _6]Cl _3$.
Thus option B is incorrect.
(C) The d-orbitals involved in s$sp^3d^2  and\  d^2sp^3$  hybridisation of the central metal ion are $d _{x^2-y^2}$  and  $d _{z^2}$ respectively.
Thus option C is incorrect.
(D) Both fac and mer isomers of $[Ma _3b _3]^{n\pm}$ are optically inactive as they contain plane of symmetry.
Thus option D is correct.

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

Select the correct order of C-O bond order in mixed phosphine carbonyl complex :

  1. $[(Ph _3P) _3Mo(CO) _3] > [(Ph _2PCl) _3Mo(CO) _3] > (PhPCl _2) _3 Mo (CO) _3]$
  2. $[(Ph _3P) _3Mo(CO) _3] > [(Ph _2PCl) _3Mo(CO) _3] < (PhPCl _2) _3 Mo (CO) _3]$
  3. $[(Ph _3P) _3Mo(CO) _3] = [(Ph _2PCl) _3Mo(CO) _3] > (PhPCl _2) _3 Mo (CO) _3]$
  4. $[(Ph _3P) _3Mo(CO) _3] < [(Ph _2PCl) _3Mo(CO) _3] > (PhPCl _2) _3 Mo (CO) _3]$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

As phenyl group increases, resonance increases and bond length increases so order is
$[(Ph _3P) _3Mo(CO) _3] > [(Ph _2PCl) _3Mo(CO) _3] < (PhPCl _2) _3 Mo (CO) _3]$