31.

The correct basicity order of the following lanthanide ions is

• La³⁺ > Lu³ > Ce³⁺ > Eu³⁺

• Ce³⁺ > Lu³⁺ > La³⁺ > Eu³⁺

• Lu³⁺ > Ce³⁺ > Eu³⁺ > La³⁺

• La³⁺ > Ce³⁺ > Eu³⁺ > Lu³⁺

Assuming the compounds to be completely dissociated in aqueous solution, identify the pair of the solutions that can be expected to be isotonic at the same temperature.

• 0.01 M urea and 0.01 M NaCl

• 0.02 M NaCl and 0.01 M Na₂SO₄

• 0.03 M NaCl and 0.02 M MgCl₂

• 0.01 M sucrose and 0.02 M glucose

In a close-packed body-centred cubic lattice of potassium, the correct relation between the atomic radius (r) of potassium and the edge-length (a) of the cube is

• r = 

• r = 

• r = $\frac{\sqrt{3}}{2}\mathrm{a}$

• r = $\frac{\sqrt{3}}{4}\mathrm{a}$

During electrolysis of molten NaCl, some water was added. What will happen?

• Electrolysis will stop

• Hydrogen will be evolved

• Some amount of caustic soda will be formed

• A fire is likely

The role of fluorspar, which is added in small quantities in the electrolytic reduction of alumina dissolved in fused cryolite is

• as a catalyst

• to make fused mixture conducting

• to lower the melting temperature of the mixture

• to decrease the rate of oxidation of carbon at anode

ADP and ATP differ in the number of

• phosphate units

• ribose units

• adenine base

• nitrogen atom

The compound that would produce a nauseating smell/ odour with a hot mixture of chloroform and ethanolic potassium hydroxide is

• PhCONH₂

• PhNHCH₃

• PhNH₂

• PhOH

For the reaction below, the structure of the product Q is

The reaction sequence given below given product R.

The structure of the product R is

Reduction of the lactol S  OH with sodium borohydride gives