HSC Science (Electronics) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions

Mention some important uses of the potassium permanganate salt.

At the freezing point ______.

Which innovative material has been developed using the lotus effect?

Complete the following reaction:

\[\ce{Na2SO3 + Cl2 + H2O -> \underline{}\underline{}\underline{}\underline{} + \underline{}\underline{}\underline{}\underline{}}\]

Describe the bonding in the tetrahedral complex Ni(CO)₄ on the basis of valence bond theory. Give the orbital diagrams of metal atoms in free state and in the complex. Mention the number of unpaired electrons in the complex.

Define the enthalpy of freezing.

Give reactions to show that SO₂ gas acts as a reducing agent.

How does entropy change in the following process? Explain.

Condensation of vapour

A compound forms hcp structure. What is the number of (a) octahedral voids, (b) tetrahedral voids, (c) total voids formed in 0.2 mol of the compound?

Give VBT description of the bonding in a square planar complex [Cu(NH₃) ₄]²⁺. Show orbital diagrams for free metal ion and metal ion in the complex. Which hybrid orbitals are used by metal for bonding? State magnetic nature of the complex.

Which flower is an example of self cleansing? Explain.

Enthalpy of fusion of ice at 0°C and 1 atmosphere is 6.01 kJ mol ^{- 1} and enthalpy of evaporation of water at 0°C and 1 atmosphere is 45.07 kJ mo1 ^{- 1}. Calculate the enthalpy of sublimation of one mole of ice at 0°C and 1 atmosphere. Write the equation for the same.

Which highly effective and cost effective nanoparticles are used for water purification?

Draw structures 01 conjugate bases of monochloroacetic acid and dichloroacetic acid. Which one is more stabilized by -I effect?

What is the action of aqueous bromine on aniline?

Write reactio between Cl₂ and water.

Write cell reaction and calculate the potential (EMF) of the cell Zn(s) | Zn²⁺(0.08 M) || Cr³⁺ (0.1 M) Cr(s) at 298 K. 
\[\ce{E^0_{Zn} = - 0.76 V and E^0_Cr = - 0.74 V}\]

Give a valence bond description of the bonding in the high spin complex [MnCl₆]³⁻ Include orbital diagram for the free metal ion and the metal ion in the complex. Indicate which hybrid orbitals the metal ion uses for bonding. Specify the number of unpaired electrons.

Explain any two applications of nanomaterials.

Write any two difficulties of setting SHE (Standard Hydrogen Electrode).