31.

In the reaction, 

X + I₂ + 2HCl $\to$SnCl₄ + 2HI

The correct option regarding X is/ are

• It is an strong reducing agent

• It is an angular molecule

• It is used as a reagent in test of Hg²⁺ radical

• All of the above

If oxide ions are arranged in hep and the aluminium ions occupy two thirds of octahedral voids. What will be the formula of the compound?

• AlO₃ 

• Al₂O₃

• (Al₂O₃)₂

• Al₃O₄

Actinides exhibit larger number of oxidation state than that of corresponding lanthanides. The reason behind this aspect is

• lesser energy difference between 5f and 6d-orbitals than between 4f and 5d-orbitals

• larger atomic size of actinides than the lanthanides

• more energy difference between 5f and 6d orbitals than between 4f and 5d-orbitals

• greater reactive nature of the actinides than the lanthanides

The E^$°$ values for Mn and Zn are more negative than expected because

• they have either half-filled and fully-filled configurations

• they can easily donate electrons

• it is quite easy to remove electrons from their orbitals

• None of the above

Two similar reactions have the same rate constant at 25$°$C, but at 35$°$C, one of the reaction has a higher rate constant than the other. The appropriate reason for this is

• due to effective collisions

• due to different activation energies

• due to different threshold energies

• due to higher population of molecules

In [CO(H2O)6]²⁺, there are three unpaired electrons present. The $\mathrm{\mu }$_calculated is 3.87 BM which is quite different from the $\mathrm{\mu }$_experimental of 4.40 BM. This is because of

• increase in number of unpaired electrons

• some contribution of the orbital motion of the electron to the magnetic moment

• change in orbital spin of the electron

• d-d transition

When an iron object is plated with tin, tin does not act as sacrificial anode in protecting against corrosion, because

• tin is more reactive than iron

• tin is less reactive than iron

• reactivity of tin and iron is same

• tin is oxidising agent while iron is not so

Consider the reaction, H₂ + X₂ $\to$ 2HX, where X is halogen. The reactivity of halogens decrease in the order of

• Cl₂ > F₂ > Br₂ > I₂

• I₂ > Br₂ > F₂ > Cl₂

• F₂ > Cl₂ > Br₂ > I₂

• I₂ > Br₂ > Cl₂ > F₂

Choose the correct statement from the following.

• The greater positive value of ${\mathrm{E}}_{\mathrm{OP}}^{°}$ indicates greater reactivity of metal

• F^- is strong oxidant while Cu²⁺ is weak reductant

• The metals placed above Mg in the electrochemical series do not decompose water at ordinary temperature

• Oxides of Hg do not decompose on heating

On the basis of Langmuir adsorption isotherm the amount of gas adsorbed at very high pressure.

• Reaches a constant limiting value

• Goes on increasing with pressure

• Goes on decreasing with pressure

• First increasing and then decreasing with pressure