Assertion (A) : Number of unpaired electron in $F e (C O)_{5}$ is four.
Reason (R) : CO is strong field ligand.

Assertion is correct but Reason is wrong

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Assertion is wrong But Reason is correct

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Assertion and Reason are correct and Reason is correct explanation of Assertion

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Assertion and Reason are correct and Reason is not correct explanation of Assertion

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A Assertion is wrong But Reason is correct
CO is strong field ligand according to crystal field theory. Fe has four unpaired electrons and CO on being strong ligand pairs them all. Two paired elecrons in 4s orbital place themselves in 3d orbital leaving 4s orbital empty. Five pairs of electrons come from CO and place them in 4s, 3d and 4p orbitals attaining $s p^{3} d^{2}$ hybridisation and hence trigonal bipyramidal shape.

Suggest Corrections

Similar questions

Assertion (A) Phenols give o-and p-nitrophenol on nitration with conc. $H N O_{3} a n d H_{2} S O_{4}$ mixture.
Reason (R) - OH group in phenol is o-,p-directing.
(a) Assertion and reason both are correct and reason is correct explanation of assertion.
(b) Assertion and reason both are wrong statements.
(c) Assertion is correct statement but reason is wrong statement.
(d) Assertion is wrong statement but reason is correct statement.
(e) Both assertion and reason are correct statements but reason is not correct explanation of assertion.

Assertion (A) Boiling points of alcohols and ethers are high.
Reason (R) They can form intermolecular hydrogen-bonding.
(a) Assertion and reason both are correct and reason is correct explanation of assertion.
(b) Assertion and reason both are wrong statements.
(c) Assertion is correct statement but reason is wrong statement.
(d) Assertion is wrong statement but reason is correct statement.
(e) Both assertion and reason are correct statements but reason is not correct explanation of assertion.

Assertion (A) Bond angle in ethers is slightly less than the tetrahedral angle.
Reason (R) There is a repulsion between the two bulky (- R) groups.
(a) Assertion and reason both are correct and reason is correct explanation of assertion.
(b) Assertion and reason both are wrong statements.
(c) Assertion is correct statement but reason is wrong statement.
(d) Assertion is wrong statement but reason is correct statement.
(e) Both assertion and reason are correct statements but reason is not correct explanation of assertion.

Assertion (A) Phenol forms 2, 4, 6-tribromophenol on treatment with $B r_{2}$ in carbon disulphide at 273K.
Reason (R) Bromine polarises in carbon disulphide.
(a) Assertion and reason both are correct and reason is correct explanation of assertion.
(b) Assertion and reason both are wrong statements.
(c) Assertion is correct statement but reason is wrong statement.
(d) Assertion is wrong statement but reason is correct statement.
(e) Both assertion and reason are correct statements but reason is not correct explanation of assertion.

Assertion (A) Ethanol is a weaker acid than phenol.
Reason (R) Sodium ethoxide may be prepared by the reaction of ethanol with aqueous NaOH.
(a) Assertion and reason both are correct and reason is correct explanation of assertion.
(b) Assertion and reason both are wrong statements.
(c) Assertion is correct statement but reason is wrong statement.
(d) Assertion is wrong statement but reason is correct statement.
(e) Both assertion and reason are correct statements but reason is not correct explanation of assertion.

Join BYJU'S Learning Program

Assertion (A) : Number of unpaired electron in Fe(CO)5 is four.Reason (R) : CO is strong field ligand.

Assertion (A) : Number of unpaired electron in $F e (C O)_{5}$ is four.
Reason (R) : CO is strong field ligand.