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

If a current of 0.5 ampere flows through a metallic wire for 2 hours, then how many electrons would flow through the wire?

Suggest a list of metals that are extracted electrolytically.

Consider the reaction: \[\ce{Cr2O^{2-}_7 + 14H^+ + 6e^- -> 2Cr^{3+} + 7H2O}\]

What is the quantity of electricity in coulombs needed to reduce 1 mol of  \[\ce{Cr2O^{2-}_7}\]?

How much charge is required for the following reduction:

1 mol of Al³⁺ to Al?

How much charge is required for the following reduction? 

1 mol of Cu²⁺ to Cu.

How much charge is required for the following reduction:

1 mol of \[\ce{MnO^-_4}\] to Mn²⁺?

A solution of Ni(NO₃)₂ is electrolysed between platinum electrodes using a current of 5 amperes for 20 minutes. What mass of Ni is deposited at the cathode?

Three electrolytic cells A, B, C containing solutions of ZnSO₄, AgNO₃ and CuSO₄, respectively, are connected in series. A steady current of 1.5 amperes was passed through them until 1.45 g of silver deposited at the cathode of cell B. How long did the current flow? What mass of copper and zinc were deposited?

Why is the ester hydrolysis slow in the beginning and becomes faster after sometime?

What are enzymes? Write in brief the mechanism of enzyme catalysis.

Name the processes from which chlorine is obtained as a by-product.

Explain on the basis of valence bond theory that [Ni(CN)₄]²⁻ ion with square planar structure is diamagnetic and the [NiCl₄]²⁻ ion with tetrahedral geometry is paramagnetic.

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 are synthetic detergents better than soap?

Explain the following term with a suitable example:

Cationic detergents