11.

Which of the following combination will form an electrovalent bond ?

• P and Cl

• NH₃ and BF₃

• H and Ca

• H and S

How many moles of Al₂(SO₄)₃ a would be in 50 gm of the substance ?

• 0.083 mol

• 0.952 mol

• 0.481 mol

• 0.140 mol

The solubility of CaF₂ in pure water is 2.3 × 10^-4 mol dm³. Its solubility product will be:

• 4.6 × 10^-4

• 4.6 × 10^-8

• 6.9 × 10^-12

• 4.9 × 10^-11

Which is the correct order of electronegativity?

• F > N < O < C

• F > N > O > C

• F > N > O < C

• F < N < O = C

The radius of hydrogen atom in the ground state is 0.53 Å. The radius of Li²⁺ ion (atomic number = 3) in a similar state is :

• 0.176 Å

• 0.30 Å

• 0.53 Å

• 1.23 Å

C-H bond energy is about 101 kcal/ mol for methane, ethane and other alkanes but is only 77 kcal/ mol for C-H bond of CH₃ in toluene. This is because :

• of inductive effect due to -CH₃ in toluene

• of the presence of benzene ring in toluene

• of resonance among the structures of benzyl radical in toluene

• aromaticity of toluene

Among BMe₃, BF₃, BCl₃ and B₂H₆ which one will be the best Lewis acid ?

• BCl₃

• BMe₃

• B₂H₆

• BF₃

Hess's law is used to calculate :

• enthalpy of reaction

• entropy of reaction

• work done in reaction

• All of the above

Which of the following is not a Lewis base ?

• NH₃

• H₂O

• AlCl₃

• None of these

Which of the following is amphoteric ?

• V₂O₃

• CuO

• V₂O₅

• NiO