Which of the following pairs involves isoelectronic ions ?

• Mn³⁺ and Fe²⁺

• Mn²⁺ and Fe³⁺

• Cr³⁺ and Mn²⁺

• Fe²⁺ and Co²⁺

Which one of the following has the highest electronegativity ?

• Br

• Cl

• P

• Si

The species that is not hydrolysed in water is

• P₄O₁₀

• BaO₂

• Mg₈N₂

• CaC₂

Which is the correct order of electronegativity?

• F > N < O < C

• F > N > O > C

• F > N > O < C

• F < N < O = C

Which one of these is not known?

• CuCl₂

• CuI₂

• CuF₂

• CuBr₂

The only non-metal which is liquid at ordinary temperature is :

• Hg

• Br₂

• NH₃

• None of these

The solubilities of carbonates decrease down the magnesium group due to a decrease in

• lattice energies of solids

• hydration energies of cations

• inter-ionic attraction

• entropy of solution formation

Pauling's electronegativity values for elements are useful in predicting :

• polarity of bonds in molecules

• position of elements in electromotive series

• co-ordination number

• dipole moment of various molecules

Which of the following is amphoteric ?

• V₂O₃

• CuO

• V₂O₅

• NiO

Identify the non-polar molecule in the set of compounds given :

HCl, HF, H₂, HBr

• H₂

• HCl

• HF, HBr

• HBr