Which of the following element has lowest melting point?

• Cr

• Fe

• Ni

• Cu

Maximum number of unpaired electrons are present in

• Gd³⁺

• Yb²⁺

• Tb²⁺

• Pm³⁺

Total number of antibonding electrons present in O₂ will be

• 6

• 8

• 4

• 2

4.

In BF₃, the B - F bond length is 1.30Å, when BF₃ is allowed to be treated with Me₃N, it forms an adduct, Me₃N $\to$ BF₃, the bond length of B - F in the adduct is

• greater than 1.30 Å

• smaller than 1.30 Å

• equal to 1.30 Å

• none of these

Which of the following is most basic?

• Al(OH)₃

• Cr(OH)₃

• La(OH)₃

• Fe(OH)₃

K₂Cr₂O₇ in acidic medium converts into

• Cr²⁺

• Cr³⁺

• Cr⁴⁺

• Cr⁵⁺

A particle is moving 3 times faster than the speed of electron. If the ratio of wavelength of particle and electron is 1.8 x 10^-4 then particle is

• neutron

• $\mathrm{\alpha }$- particle

• deuteron

• tritium

What will be the solubility product of AX₃?

• 27S⁴

• 4S³

• 36S⁴

• 9S³

Which thermodynamic parameter is not a state function?

• q at constant pressure

• q at constant volume

• W at adiabatic

• W at isothermal

Assertion : Bond dissociation energy is F₂ > Cl₂.

Reason : Cl₂ has more electronic repulsion than F₂.

• 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.