31.

Which two of the following salts are used for preparing iodized salt?

(i) KIO₃, (ii) KI, (iii) I₂, (iv) HI

 

• (i) and (ii)

• (i) and (iii)

• (ii) and (iv)

• (iii) and (iv).

The compound used in enrichment ofuranium for nuclear power plant is

• U₃O₈

• UF₆

• UO₂(NO₃)₂

• UCl₄

The Ca²⁺ and F^- are located in CaF₂ crystal, respectively at face centred cubic lattice points and in

• tetrahedral voids

• half of tetrahedral voids

• octahedral voids

• half of octahedral voids

For the reaction, 2N₂O₅ $\to$ 4NO₂+ O₂ rate of reaction is

• $\frac{1}{2}\frac{\mathrm{d}}{\mathrm{dt}}\left[{\mathrm{N}}_2{\mathrm{O}}_5\right]$

• $2\frac{\mathrm{d}}{\mathrm{dt}}\left[{\mathrm{N}}_2{\mathrm{O}}_5\right]$

• $\frac{1}{4}\frac{\mathrm{d}}{\mathrm{dt}}\left[{\mathrm{NO}}_2\right]$

• $4\frac{\mathrm{d}}{\mathrm{dt}}\left[{\mathrm{NO}}_2\right]$

A 5% solution (by mass) of cane sugar in water has freezing point of 271 K and freezing point of, pure water is 273.15 K. The freezing point of a 5% solution (by mass) of glucose in water is

• 271 K

• 273.15 K

• 269.07 K

• 277.23 K.

The products formed when an aqueous solution of NaBr is electrolysed in a cell having inert electrodes are

• Na and Br₂

• Na and O₂

• H₂, Br₂ and NaOH

• H₂ and O_2.

Assertion : ${\mathrm{E}}^{°}$ for Mn³⁺/Mn²⁺ is more positive than Cr³⁺/Cr³⁺

Reason : The third ionization energy of Mn is larger than that of Cr.

• If both assertion and reason are true and reason is the correct explanation of the assertion.

• If both assertion and reason are true but reason is not the correct explanation of the assertion.

• If assertion is true, but reason is false.

• Both assertion and reason are false statements.

Assertion : K₂Cr₂O₇ is used as primary standard in volumetric analysis.

Reason : It has a good solubility in water.

• If both assertion and reason are true and reason is the correct explanation of the assertion.

• If both assertion and reason are true but reason is not the correct explanation of the assertion.

• If assertion is true, but reason is false.

• Both assertion and reason are false statements.

Assertion : According to transition state theory, for the formation of an activated complex, one of the vibrational degrees of freedom is converted into a translational degree of freedom.

Reason: Energy of the activated complex is higher than the energy of reactant molecules.

• If both assertion and reason are true and reason is the correct explanation of the assertion.

• If both assertion and reason are true but reason is not the correct explanation of the assertion.

• If assertion is true, but reason is false.

• Both assertion and reason are false statements.

Assertion : Sb₂S₃ is not soluble in yellow ammonium sulphide.

Reason : The common ion effect due to S^2- ions reduces the solubility of Sb₂S₃.

• If both assertion and reason are true and reason is the correct explanation of the assertion.

• If both assertion and reason are true but reason is not the correct explanation of the assertion.

• If assertion is true, but reason is false.

• Both assertion and reason are false statements.