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

Write any four applications of electrochemical series

Write chemical formulae of the following ores :

(a) Calamine 

(b) Haematite                     

(c) Magnetite

(d) Corundum

What is the action of hot/concentrated nitric acid on - Arsenic   

How much electricity in terms of Faraday is required to produce 20 g of Ca from molten CaCl₂?

(Given: Molar mass of Calcium is 40 g mol⁻¹.)

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

C₆H₅MgBr + C0₂ `(`> ‘A’   `(PCl_5)/()`> ‘B’

Fe₂O₃ is reduced to spongy iron near the top of blast furance by

(A) H₂

(B) CaO

(C) SiO₂

(D) CO

Mention names and formulae of two ores of alumunium.

ln which pair highest oxidation states of transition metals are found:

Calculate magnetic moment of  `Fe_((aq))^(2+) ion (Z=26).`

Why does p-nitrochlorobenzene undergo displacement reactions readily with attack of nucleophilic HO^{Θ ion}?

Why +2 oxidation state of manganese is more stable?

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?