The ligand called $\mathrm{\pi }$ acid is

• CO

• NH₃

• C₂O${}_4^{2-}$

• ethylene diamine

Which of the following imparts green colour to the burner flame?

• B(OMe)₃

• Na(OMe)

• Al(OPr)₃

• Sn(OH)₂

Assertion : Alcohols are dehydrated to hydrocarbons in the presence of acidic zeolites.

Reason : Zeolites are porous catalysts.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

Assertion : Haemoglobin is an oxygen carrier.

Reason : Oxygen binds as O₂^- to Fe of haemoglobin.

• If both assertion and reason are true and the reason is the correct explanation of the assertion.

• If both assertion and reason are true and the reason is not the correct explanation of the assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Hardest compound of boron is

• magnesium boride

• aluminium boride

• boron nitride

• boron carbide

176.

Among Be, B, Mg and Al, the second ionisation potential is maximum for

• B

• Be

• Mg

• Al

The reaction of methyltrichloroacetate (Cl₃CCO₂Me) with sodium methoxide (NaOMe) generates

• carbocation

• carbene

• carbanion

• carbon radical

Assertion: Diamond is a bad conductor.
Reason: Graphite is a good conductor.

• If both assertion and reason are true and reason is a correct explanation of the assertion.

• If both the assertion and reason are true but the reason is not a correct explanation of the assertion.

• If the assertion is true but the reason is false.

• If both the assertion and reason are false.

The paramagnetic behaviour of B₂ is due to the presence of:

• two unpaired electrons in ${\mathrm{\pi }}_{\mathrm{b}}$ MO

• two unpaired electrons in $\stackrel{*}{\mathrm{\pi }}$ MO

• two unpaired electrons in $\stackrel{*}{\mathrm{\sigma }}$ MO

• two unpaired electrons in ${\mathrm{\sigma }}_{\mathrm{b}}$ MO

Which of the following structure is similar to graphite?

• BN

• B

• B₄C

• B₂H₆