51.

Which of the following compounds shows optical isomerism?

• [Cu(NH₃)₄]⁺²

• [ZnCl₄]^-2

• [Cr(C₂O₄)₃]^-3

• [Cr(C₂O₄)₃]^-3

Which one of the following cyano complexes would exhibit the lowest value of paramagnetic behaviour?

• [Cr(CN)₆]^-3

• [Mn(CN)₆]^-3

• [Fe(CN)₆]^-3

• [Fe(CN)₆]^-3

The photon of hard gamma radiation knocks a proton out of ²⁴₁₂Mg nucleus to form

• the isotope of parent nucleus

• the isobar of parent nucleus

• the nuclide
  

• the nuclide
  

Which types of isomerism is shown by 2,3-dichlorobutane?

• Diastereo

• Optical

• Geometric

• Geometric

Equimolar solutions in the same solvent have

• Same boiling point but different freezing point

• Same freezing point but different boiling point

• Same boiling and same freezing points

• Same boiling and same freezing points

The value of the ‘spin only’ magnetic moment for one of the following configurations is 2.84 BM. The correct one is

• d⁴ (in strong ligand filed)

• d⁴ (in weak ligand field)

• d³ (in weak as well as in strong fields)

• d³ (in weak as well as in strong fields)

Which of the following factors may be regarded as the main cause of lanthanide contraction?

• Poor shielding of one of 4f electron by another in the subshell

• Effective shielding of one of 4f electrons by another in the subshell

• Poorer shielding of 5d electrons by 4f electrons

• Poorer shielding of 5d electrons by 4f electrons

t₁/4 can be taken as the time taken for the concentration of a reactant to drop to 3/4 of its initial value. If the rate constant for a first order reaction is K, the t₁/4 can be written as

• 0.10 / K

• 0.29 / K

• 0.69 / K

• 0.69 / K

An amount of solid NH₄HS is placed in a flask already containing ammonia gas at a certain temperature and 0.50 atm. Pressure. Ammonium hydrogen sulphide decomposes to yield NH₃ and H₂S gases in the flask. When the decomposition reaction reaches equilibrium, the total pressure in the flask rises to 0.84 atm. The equilibrium constant for NH₄HS decomposition at this temperature is

• 0.30

• 0.18

• 0.17

• 0.17

Which of the following is a polyamide?

• Teflon

• Nylon – 6,6

• Terylene

• Terylene