Choose the wrong statement from the following 

• The 'silver' UK coins are made of Ag/ Ni alloy 

• TiO₂ is used in the pigment industry

• MnO₂ is used in the dry battery cells

• V₂O₅ catalyses the oxidation of SO₂ in the manufacture of sulphuric acid

The correct order of first ionisation enthalpies of the following elements is

• Be > Mg > Ca > Sr > Ra > Ba

• Ra > Ba > Sr > Ca > Mg > Be

• Be > Mg > Ca > Sr > Ba > Ra

• Ra > Sr > Ba > Mg > Ca > Be

The correct discending order of oxidising power of the following is

• ${\mathrm{Cr}}_2{\mathrm{O}}_7^{2-} > {\mathrm{MnO}}_4^{-} > {\mathrm{VO}}_2^{+}$

• ${\mathrm{MnO}}_4^{-} > {\mathrm{Cr}}_2{\mathrm{O}}_7^{2-} > {\mathrm{VO}}_2^{+}$

• ${\mathrm{VO}}_2^{+} > {\mathrm{MnO}}_4^{-} > {\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}$

• ${\mathrm{MnO}}_4^{-} > {\mathrm{VO}}_2^{+} > {\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}$

234.

The number of electrons that are involved in the reduction of permanganate to manganese (II) salt, manganate and manganese dioxide respectively are

• 5, 1, 3

• 5, 3, 1

• 2, 7, 1

• 5, 2, 3

The ionisation enthalpy of He⁺ ion is 19.60 10^-18 J atom^-1. The ionisation enthalpy of Li²⁺ ion will be

• 84.2 × 10^-18 J atom^-1

• 44.10 × 10^-18 J atom^-1

• 63.20 × 10^-18 J atom^-1

• 21.20 × 10^-18 J atom^-1

Among the elements B, Mg, Al and K the correct order of increasing metallic character is

• B < Al < Mg < K

• B < Mg < Al < K

• Mg < B < Al < K

• Mg < Al < B < K

Which one of the following is an amphoteric oxide?

• Mn₂O₇

• CrO

• V₂O₄

• Cr₂O₃

Molecules/ ions and their magnetic properties are given below-

The correctly matched pairs in the above is

• i - 5; ii - 3; iii - 2; iv - 1; v - 4

• i - 3; ii - 5; iii - 1; iv - 4; v - 2

• i - 5; ii - 3; iii - 1; iv - 2; v - 4

• i - 5; ii - 3; iii - 1; iv - 4; v - 2

Among the following, the element of highest first ionisation enthalpy is

• C

• Ne

• Be

• N

Arrange the following in the order of increasing mass (atomic mass O = 16, Cu = 63, N = 14)

I. One atom of oxygen

II. One atom of nitrogen

III. 1 × 10^-10 mole of oxygen

IV. 1 × 10^-10  mole of copper

• II < I < III < IV

• I < II < III < IV

• III < II < IV < I

• II < IV < I < III