Which of the following will have the shape of a trigonal bipyramid?

• PF₃Cl₂

• IF₅

• BrF₅

• SbF${}_5^{2-}$

The example of σ-complex is

• Fe(η⁵-C₅H₅)₂

• [Cr(CO)₆]

• Al₂(CH₃)₆

• Zeiss salt

The bond present in N₂O₅ are

• only ionic

• covalent and coordinate

• only covalent

• covalent and ionic

4.

5 millimoles of caustic potash and 5 millimoles of oxalic acid are mixed and dissolved in 100 mL water. The solution will be

• basic

• acidic

• neutral

• cannot say

How many moles of O₂ can be obtained by electrolysis of 90 g H₂O?

• 5.0 mol

• 0.5 mol

• 2.5 mol

• 0.25 mol

Four different sets of quantum numbers for 4 electrons are given below:

e₁ = 4, 0, 0, -$\frac{1}{2}$

e₂ = 3, 1, 1, -$\frac{1}{2}$

e₃ = 3, 2, 2, +$\frac{1}{2}$

e₄ = 3, 0, 0, +$\frac{1}{2}$

The order of energy of e₁, e₂, e₃, e₄ is 

• e₁ > e₂ > e₃ > e₄

• e₄ > e₃ > e₂ > e₁

• e₃ > e₁ > e₂ > e₄

• e₂ > e₃ > e₄ > e₁

Which of the following nuclei is most unstable?

• ${}_{20}{}^{40}\mathrm{Ca}$

• ${}_{35}{}^{55}\mathrm{Mn}$

• ${}_{50}{}^{119}\mathrm{Sn}$

• ${}_{13}{}^{30}\mathrm{Al}$

Electron affinity is positive when

• O^- is formed from O

• O^2- is formed from O^-

• O⁺ is formed from O

• electron affinite is always a negative value

When solid melts, there will be

• a decrease in enthalphy

• a decrease in free energy

• a decrease in entropy

• all the above factors remain constant

Which solution is a buffer?

• Acetic acid + NaOH (equimolar ratio)

• Acetic acid + NaOH (1 : 2 molar ratio)

• Acetic acid + NaOH (2 : 1 molar ratio)

• HCl + NaOH (equimolar ratio)