Among [Ni(CO)₄], [Ni(CN)₄]²⁻, [ NiCl₄]²⁻ species, the hybridization states of the Ni atom are respectively:
(At. No. of Ni = 28)

A set of ions among the following that have a 3d² electronic configuration is:

1. ${\mathrm{Ti}}^{+},{\mathrm{V}}^{4+},{\mathrm{Cr}}^{6+},{\mathrm{Mn}}^{7+}$

2. ${\mathrm{Ti}}^{4+},{\mathrm{V}}^{3+},{\mathrm{Cr}}^{2+},{\mathrm{Mn}}^{3+}$

3. ${\mathrm{Ti}}^{2+},{\mathrm{V}}^{3+},{\mathrm{Cr}}^{4+},{\mathrm{Mn}}^{5+}$

4. ${\mathrm{Ti}}^{3+},{\mathrm{V}}^{2+},{\mathrm{Cr}}^{3+},{\mathrm{Mn}}^{4+}$

Coordination compound that would exhibit optical isomerism is:

The rapid change of pH near the stoichiometric point of an acid-base titration is the basis of indicator detection. pH of the solution is related to the ratio of the concentrations of the conjugate acid (\(HIn\)) and base (\(In^–\)) forms of the indicator, as per the expression:

Which of the following reactions, in the presence of anhydrous AlCl₃, leads to the formation of ethylbenzene (Ph–Et)?

1. ${\mathrm{CH}}_3-\mathrm{CH}={\mathrm{CH}}_2+{\mathrm{C}}_6{\mathrm{H}}_6$

2. ${\mathrm{H}}_2\mathrm{C}={\mathrm{CH}}_2+{\mathrm{C}}_6{\mathrm{H}}_6$

3. ${\mathrm{H}}_3\mathrm{C}-{\mathrm{CH}}_3+{\mathrm{C}}_6{\mathrm{H}}_6$

4. ${\mathrm{H}}_3\mathrm{C}-{\mathrm{CH}}_2\mathrm{OH}+{\mathrm{C}}_6{\mathrm{H}}_6$

The molecular formula of diphenylmethane is C₁₃H₁₂. find out the number of structural isomers possible when one of the hydrogens is replaced by a chlorine atom:

A solid compound 'X' on heating gives CO₂ gas and a residue. The residue mixed with water forms 'Y'. On passing an excess of CO₂ through 'Y' in water, a clear solution, 'Z' is obtained. On boiling 'Z', compound 'X' is reformed. The compound 'X' is:

1. ${\mathrm{CaCO}}_3$

2. ${\mathrm{Na}}_2{\mathrm{CO}}_3$

3. ${\mathrm{K}}_2{\mathrm{CO}}_3$

4. $\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2$

The work done during the expansion of a gas from a volume of 4 dm³ to 6 dm³ against a constant external pressure of 3 atm is:

1. –608 J

2. +304 J

3. –304 J

4. –6.00 J 

The lone pairs in the BrF₃ molecule, occupy equatorial positions to minimize:

Blood analysis of a patient reveals an unusually high quantity of carboxy-haemoglobin content. Which of the following conclusions is most likely to be correct? The patient has been inhaling polluted air containing unusually high content of: