PUC Science 2nd PUC Class 12 - Karnataka Board PUC Question Bank Solutions

Predict the number of unpaired electrons in the square planar [Pt(CN)₄]²⁻ ion.

Discuss the nature of bonding in the following coordination entity on the basis of valence bond theory:

[Fe(CN)₆]⁴⁻

[Cr(NH₃)₆]³⁺ is paramagnetic while [Ni(CN)₄]²⁻ is diamagnetic. Explain why?

Discuss the nature of bonding in the following coordination entity on the basis of valence bond theory:

[FeF₆]³⁻

Discuss the nature of bonding in the following coordination entity on the basis of valence bond theory:

[Co(C₂O₄)₃]³⁻

Discuss the nature of bonding in the following coordination entity on the basis of valence bond theory:

[CoF₆]³⁻

How will you convert ethanal into the following compound?

But-2-enoic acid

Give a simple chemical test to distinguish between the following pair of compounds:

Acetophenone and Benzophenone

Give a simple chemical test to distinguish between the following pair of compounds:

Phenol and Benzoic acid

Give a simple chemical test to distinguish between the following pair of compounds:

Benzoic acid and Ethyl benzoate

Give a simple chemical test to distinguish between the following pair of compounds:

Pentan-2-one and Pentan-3-one

Give a simple chemical test to distinguish between the following pair of compounds:

Benzaldehyde and Acetophenone

An organic compound contains 69.77% carbon, 11.63% hydrogen and rest oxygen. The molecular mass of the compound is 86. It does not reduce Tollens’ reagent but forms an addition compound with sodium hydrogensulphite and give positive iodoform test. On vigorous oxidation it gives ethanoic and propanoic acid. Write the possible structure of the compound.

Complete the synthesis by giving missing starting material, reagent or product.

How the following conversion can be carried out?

Chlorobenzene to p-nitrophenol

List the important sources of sulphur.

Write the order of thermal stability of the hydrides of Group 16 elements.

Why is H₂O a liquid and H₂S a gas?

Which of the following does not react with oxygen directly?

Zn, Ti, Pt, Fe

Why does NH₃ form hydrogen bond but PH₃ does not?