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

Derive a relation between ΔH and ΔU for a chemical reaction. Draw neat labelled diagram of calomel electrode. Resistance and conductivity of a cell containing 0.001 M KCI solution at 298K are 1500Ω and 1.46x10^-4 S.cm^-1 respectively.

Draw neat and labelled diagram of Bessermer converter used in the extraction of copper.

Explain brown ring test with the help of chemical equation

Number of faradays of electricity required to liberate 12 g of hydrogen is:

Purification of aluminium by electrolytic refining is carried out by

(a)Hoope process

(b)Hall process

(c)Baeyer process

(d)Serperck process

Identify the weakest base amongst the following :

(a) p- methoxyaniline

(b) o-toluidine

(c) benzene - 1, 4 - diamine

(d) 4 - aminobenzoic acid

What happens if external potential applied becomes greater than E°cell of electrochemical cell?

Following reactions occur at cathode during the electrolysis of aqueous sodium chloride solution:

Na+(aq) + e⁻ ⟶ Na (s) E⁰ =  2.71 V

H+(aq) + e⁻ ⟶ `1/2`  H₂ (g) E⁰ = 0.00 V

On the basis of their standard reduction electrode potential (E⁰) values, which reaction is feasible at the cathode and why?

In the extraction of Al, impure Al₂O₃ is dissolved in conc. NaOH to form sodium aluminate and leaving impurities behind. What is the name of this process?

Define the following term: Primitive unit cells

How will you distinguish between the following pair of terms?

Crystal lattice and unit cell

Define the following terms : Molarity

Account for the following:

Zn is not considered as a transition element.

Draw the structure of aspirin.

An antifriction alloy made up of antimony with tin and copper, which is extensively used in machine bearings is called _______.

(A) Duralumin

(B) Babbitt metal

(C) Spiegeleisen

(D) Amalgam

Fe2+ ions react with nitric oxide formed from reduction of nitrate and yields a brown  coloured complex _____________.

On passing 1.5 F charge, the number of moles of aluminium deposited at cathode are _______ [Molar mass of Al = 27 gram mol^–1]

(A) 1.0

(B) 13.5

(C) 0.50

(D) 0.75

Write any two uses of H₂SO₄

Define Leaching.

`CH_3-CH_2-Br"Alcoholic KOH"/""> B " HBR"/"">C"Na/Eather"/"">D`, the Compound D is

(A) ethane

(B) propane

(C) n-butane

(D) n-pentane