HSC Science (General) इयत्ता १२ वी - Maharashtra State Board Question Bank Solutions

1.0 x10^-3Kg of urea when dissolved in 0.0985 Kg of a solvent, decreases freezing point of the solvent by 0.211 k. 1.6x10 Kg of another non-electrolyte solute when dissolved in 0.086 Kg of the same solvent depresses the freezing point by 0.34 K. Calculate the molar mass of the another solute. (Given molar mass of urea = 60)

Write one statement of first law of thermodyamics and its mathematical expression.

Write one statement of first law of thermodyamics and its mathematical expression.

Calculate E_cell and ΔG for the following at 28°C :

Mg_(s) + Sn²⁺( 0.04M ) → Mg²⁺( 0.06M ) + Sn_(s)

E°_cell = 2.23V. Is the reaction spontaneous ?

Identify the product ‘D’ in the following sequence of reactions:

\[\ce{H3C - CH2 - CH2 - Cl \underset{KOH}{\overset{Alc}{->}} 'B' \overset{HBr}{->} 'C' \underset{Elther}{\overset{Na}{->}}'D'}\]

Primary and secondary nitroalcanes containing α - H atom show property of -

1. chain isomerism
2. tautomerism
3. optical isomerism
4. geometrical isomerism

Write mechanism of Aldol addition reaction.

The hybridisation of phosphorus in phosphorus pentachloride is _______.

(A) dsp³

(B) sp³ d

(C) d² sp³

(D) sp³ d²

The rate constant for a first order reaction is 100 s^–1. The time required for completion of 50% of reaction is _______.

(A) 0.0693 milliseconds

(B) 0.693 milliseconds

(C) 6.93 milliseconds

(D) 69.3 milliseconds

Derive an expression for maximum work in isothermal reversible expansion of two moles of an ideal gas.

Derive an expression for maximum work in isothermal reversible expansion of two moles of an ideal gas.

Can copper sulphate solution be stored in an iron vessel? Explain.

Write chemical formula of the following oxoacids of chlorine:

a. Hypochlorous acid

b. Chlorous acid

c. Chloric acid

d. Perchloric acid

Identify ‘A’ and ‘B’ in the following reaction :

\[\ce{CH3 - CH = CH2 ->[HBr]'A' ->[alc.KOH]'B'}\]

What is the action of nitrous acid on primary nitroalkane?

Write the reactions involved in the preparation of Teflon.

The atomicity of sulphur in orthorhombic sulphur is______________ .

(a) 8                                

(b) 6                                 

(c)  4                                

(d)  2

Sucrose decomposes in acid solution to give glucose and fructose according to the first order rate law. The half life of the reaction is 3 hours. Calculate fraction of sucrose which will remain after 8 hours.

Define Cryoscopic constant.

Draw the structure of: Orthophosphoric acid