Chemistry 2013-2014 HSC Science (General) 12th Standard Board Exam Question Paper Solution

The Arrhenius equation is_________________ .

(a)`k=Ae^(RT/E_a)`                                                    

(b)`A=ke^(-E_a/(RT))`

(c)`k=Ae^(-(RT)/E_a)`

(d)`k=Ae^(-E_a/(RT))`

If the enthalpy of vaporisation of water at 100^oC is 186.5 J.mol^-1, the entropy of vaporization will be_____________ .

(a) 4.0 J . K^-1. mol-¹                                               

(b) 3.0 J . K^-l.  mol^-1

(c) 1.5 J - K^-1. mol-¹                                             

(d) 0.5 J . K^-l. mol^-1

The atomicity of sulphur in orthorhombic sulphur is______________ .

(a) 8                                

(b) 6                                 

(c)  4                                

(d)  2

The major binding force in diamond is_______________ .

(a) Covalent bond                                                  

(b)  Ionic bond

(c) Metallic bond                                                   

(d)  Co-ordinate covalent bond

The boiling point of water at high altitude is low. because________________ .

(a) the temperature is low.                                         

(b) the atmospheric pressure is low.

(c) the temperature is high.

(d) the atmospheric pressure is high

The molar conductivity of cation and anion of salt BA are 180 and 220 mhos respectively. The molar conductivity of salt BA at infinite dilution is_____________ .

(a) 90 mhos.cm²                                                                             

(b) 110 mhos.cm².mol^-1

(c) 200 mhos.cm².mol^-1                                                                 

(d) 400 mhos.cm².mol^-1

What is the process in which concentrated ore is reduced to the corresponding metal by heating at high temperature with a reducing agent?

(a) Polling                      

(b) Pyrometallurgy

(c) Hydrometallurgy

(d) Calcination

Describe anomalous behaviour of oxygen as compared with other elements of group 16 with reference to -
(a) Magnetic property                                        
(b) Oxidation state
(c) Hydrides

What is the value of for the following reaction at 298 K -

6CO₂+ 6H₂0_(l) → C6H₁₂0_6(s) ⁺ 60_2(g),

Given that: ΔG° = 2879 kj mol^-1, AS = -210 JK^-1 mol^-1.

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.

A solution containing 0.73 g of camphor (molar mass 152 g . mol^-1) in 36.8 g of acetone (boiling point 56.3°C) boils at 56.55°C. A solution of 0.564 g of unknown compound in the same weight of acetone boils at 56.46^oC. Calculate the molar mass of the unknown compound.

Describe triclinic crystal lattice with the help of a diagram.

Write any four applications of electrochemical series

State and explain Hess’s law of constant heat summation.

Distinguish between Order and Molecularity of reaction.

With the help of the equation ΔG° = - nFE^o_cell. Explain that cell potential is an intensive property.

Describe the laboratory method of preparation of ammonia

Define van’t Hoff factor.

How van’t Hoff factor is related to the degree of dissociation?

Write chemical formulae of the following ores :

(a) Calamine 

(b) Haematite                     

(c) Magnetite

(d) Corundum

Write the reactions involved in extraction of silver from its ore by leaching process.

Derive the equation : W = - P_extAV

A unit cell of iron crystal has edge length 288 pm and density 7.86 g.cm^-3. Find the number of atoms per unit cell and type of the crystal lattice.

Given : Molar mass of iron = 56 g.mol^-1; Avogadro's number N_A = 6.022 x 10²³.

Define Cryoscopic constant.

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

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

Draw the structure of: Orthophosphoric acid 

Draw the structure of: Pyrophosphoric acid

How much electricity in terms of Faraday is required to produce 20 g of \[\ce{Ca}\] from molten \[\ce{CaCl2}\]?

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

How much electricity in terms of Faraday is required to produce 40.0 g of \[\ce{Al}\] from molten \[\ce{Al2O3}\]?

(Given: Molar mass of Aluminium is 27 g mol⁻¹.)

Which of the followings is a trihydric alcohol ?

(a) n-propyl alcohol

(b) Glycerol                         

(c)  Glycol                       

(d) Glycine

Alkyl halides are -

(a) Mono halogen derivatives of alkanes 

(b) Di halogen derivatives of alkanes

(c) Tri halogen derivatives of alkanes

(d) Tetra halogen derivatives of alkanes

Mohr’s Salt is -

(a) Ferrous ammonium sulphate

(b) Ferrous sulphate

(c) Ammonium sulphate

(d) Ferric sulphate

Which of the following is polyamide ?

(a) Teflon

(b) Nylon  6,6

(c) Terylene

(d) Bakelite

Vitamin ‘C’ belongs to the class of—

(a) Vitamins of aliphatic series

(b) Vitamins of aromatic series

(c) Vitamins of alicyclic series

(d) Vitamins of heterocyclic series

What is the IUPAC name of 

α - Amino butanoic acid    

2 - Amino butyric acid

α - Aminobutyric acid  

2 - Amino butanoic acid

Which among the following molecular formulae represents urotropine?

(a) C₆H₁₂N₄

(b) C₆H₂₄H₄                    

(c) C₆H₁₂N₄O₂

(d) C₆H₂4N₄O₂

Write the structures of - 3-chloro-3-ethylhex-1-ene

Write the structures of -1-Iodo-2, 3-dimethylbutane

Write the structures of - 1, 3, 5 - tribromobenzene

What is the action of acidified potassium dichromate on - SO₂

What is the action of acidified potassium dichromate on - KI 

Draw structure of dichromate ion

Describe laboratory method for preparation of glucose.

Write the reaction that indicates the presence of -CHO group in glucose

What will be the action of the mixture of sodium nitrite and dilute hydrochloric acid on ethyl amine

What will be the action of the mixture of sodium nitrite and dilute hydrochloric acid on aniline

What will be the action of the mixture of sodium nitrite and dilute hydrochloric acid on triethyl amine

What are chemical twins? Write ‘two’ examples.

Explain the term Antiseptics

Explain trem Analgesics.

Draw the simple Fisher projection formulae of D - (+) - glucose and D - (-) - fructose

Classify the following ligands into monodentate and polydentate —

1. Ammonia
2. Carbon monoxide
3. Ethylene diamine
4. Ethylene diamine tetra acetate ion

State and explain Markownikoff's rule with suitable example

How are propan-1-amine and propan-2-amine prepared from oxime?

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

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

What is the action of the following reagents on phenol - Bromine in CS₂ at low temperature.

What is the action of the following reagents on phenol - H₂SO₄ at room temperature.

Write the structure and IUPAC names of all the metamers represented by formula C₄H₁₀

Write balanced chemical equations for action of ammonia on - formaldehyde

Write balanced chemical equations for action of ammonia on - acetaldehyde

Write balanced chemical equations for action of ammonia on - acetone

Write ‘four’ characteristics of co-ordinate complex ion.

How is Nylon 6, 6 prepared?

Write any ‘two' uses of terylene.

Write ‘four’ physical methods of preserving food materials