CHEMISTRY HSSC-II (2012)

SECTION-A

 NOTE:- Section-A is compulsory. All parts of this section are to be answered on the question paper itself. It should be completed in the first 25 minutes and handed over to the Centre Superintendent Deleting/overwriting is not allowed. Do not use lead pencil.

 Ql. Circle the correct option i.e. A/B/C/D. Each part carries one mark.

• Which of the following oxides is most acidic?
  
  A) CO₂
  B) Al₂O₃
  C) B₂O₃
  D) Cl₂O₃
  
  
• Chemical formula of plaster of pans is
  
  A) CaSO₄ ½ H₂OB
  B) (CaSO₄)₂.H₂O
  C) CaSO₄.2H₂O
  D) Both A and B
  
  
• Orthoboric acid H₃BO₃; when heated to red hot, gives
  
  A) HBO₂
  B) H₂B₄O₇
  C) B₂O₃
  D) H₆B₄O₉
  
  
• Salts of HCIO₄, are known as

A) Hypochlorite
B) Perchlorate
C) Chlorite
D) Chlorate

• Oxidation state of 'Co’ in[Co(NH₃)₄Cl₂]Cl is
  
  A) 3
  B) +1
  C) +2
  D) -2

• Increasing order of electronegativity
  
  A) Cl < S < P
  B) S < Cl < P
  C) P < S < Cl
  D) S< P < Cl  
  
  
• When CO, is bubbled through an aqueous suspension of Ca(OH), the product formed is:
  
  A) Ca(OH)₂
  B) Ca(HCO₃)₂
  C) H₂CO₃
  D) H₂O
  
  
• Which of the following pairs of substances is Isomers?
  
  A) Ethyl benzene and 3. 3-Dimelhyl pentane
  B) Cyclopentanol and 2 - Pentanone
  C) 2 - Pentanol and 3 - Methyl butanone
  D) Propyl ethanoate and Methyl propanoate

• Chlorobenzene reacts with 'Mg' in dry ether to give a compound X. which further reacts with ethanol to give_________:
  
  A) Benzene
  B) Phenol
  C) Ethyl benzene
  D) Phenyl ether           

• When ethyl iodide reacts with sodium methoxide. it gives         
  
  A) Methyl ethyl ether
  B) Diethyl ether
  C) Ethanol
  D) Sodium ethoxide
  
  
• Acetone undergoes reduction with zinc amalgam in HCI to form propane This is known as    
  
  A) Clemmensen reduction          
  B) Wolf Kishner reduction
  C) Aldo! condensation   
  D) Hydrogenation           
  
  
• Which of the following is an addition polymer?
  
  A) Polystyrene
  B) Polyester
  C) Epoxyresins
  D) Bakelite                                
  
  
• Which of the following is NOT present in RNA?
  
  A) Uracil
  B) Phosphate
  C) Thymine
  D) Ribose        
            
• Which of the following primary alcohols will give lodoform test?
  
  A) Ethanol
  B) Methanol
  C) 1 - Propanol
  D) 2 - Propanol
   
• Which of the following contains oxygen as hetero atom?
  
  A) Furan
  B) Pyrrole
  C) Thiophene
  D) Pyridine
  
• Kolbe's electrolysis of sodium n-butyrate (CH₃ CH₂ CH₂ COONa) gives:
  
  A) C₈H₁₆
  B) C₆ H₁₄
  C) C₈H₁₈
  D) C₆H1₂

• Acetic acid undergoes reduction with LOU I, to give
  
  A) Ethanol
  B) Ethane
  C) Ethanal
  D) Ethyne

SECTION- B

Answer any FOURTEEN parts. The answer to each part should not exceed 5 to 6 lines:   
 
Q NO.2                  

• What are Complexes?
• Write the systematic name
• Why Fe⁺³ do not exist in solution?
• Give the electronic structure of nitrous acid
• Nitrous acid decolorizes bromine water Explain this behavior with the help of chemical equation 
• Write a balanced chemical equation to show, how nitrous acid oxidizes HI.
  
• Give reasons.
  A)LiCI is covalent but NaCI is ionic .
  B)Phosphorus forms both PC1₃ and PCl₅ but nitrogen forms only NCI
  
• What is the action of heat on
  A)LiNO₃ 
  B)NaNO₃
  C)LiOH
  
• How is borax prepared from colemanite? Give the chemistry of Borax Bead test                      
• Oxides of relatively less electropositive metals are Amphoteric in nature.
  A)ZnO is amphoteric. Justify this statement
  B)Arrange the following oxides of Manganese in order of increasing acidic character.   Mn₂O₃,  MnO,  Mn₂O₇, MnO₂
  
• Write down the names and formulae of two oxyacids of chlorine having +3 and  +7 oxidation states.
  A) Why are the oxyacids of chlorine stronger than the corresponding oxyacids of bromine and iodine?
  
• Give complete and balanced chemical equations for the reaction betweeen
  A) Zinc with cone HNO₃
  B) Copper with hot conc. H₂SO₄
  C) NaBr with conc. H₂SO₄
  
• Write down the names and formulae of two non-silicate ores of Aluminium.          
  A) Explain why Aluminium is used in flash light photography?
  B) Explain why Aluminium is often used to remove air bubbles from molten metals.    
  
• A) What is the effect of branching on the boiling points of Alkanes?
  B) What are the three different alkenes that yield 2 - methyl butane, when they are hydrogenated in the presence of a catalyst?
  
• Explain why:
  A) Hydroxyl group (-OH) in phenol is ortho-para directing.
  B) Phenol undergoes Niteration than Nitrobenzene.
  
• What happens when
  A) 2 - Methyl 2 - butene is ozonolysed, followed by Zn H₂O treatment
  B) Acetaldehyde is treated with NaCN / HCI and the product is followed by acid hydrolysis
  C) A secondary Alcohol ‘A’ C3H8O reacted with thionyl chloride to give compound ‘B’ C3H7Cl. Compound ‘B’ reacted with Benzene in the presence of AlCl3 to give compound 'C' C₉H₁₂ Identify ‘A’, ‘B’and ‘C’.
  
• A) Write the formula of 2,4 - Dinitrophenyl hydrazine and Semicarbazide.
  B) Give the mechanism of the reaction between formaldehyde and hydrazine.
  
• Starch is a mixture of Amylose and amylopectin.
• Point out the structural difference between amylose and amylopectin.
  A) How they can be differentiated chemically?
  
• Write the structural formula of the following
  A) Acrylonilrile
  B) Acetophenone
  C) Adipic acid                   
• How will you convert:
  A) Acetic acid to acetaldehyde
  B) Ethyl bromide to propionic acid           
  
• Predict the products:
   (Image)
• Differentiate between the following pairs of compounds? Also give your observations with the help of only one valid chemical test in each case
  A) Butyne and 2 - Butyne b
  B) Methanol and Ethanol  
  C) Aldehydes and Ketones 

SECTION- C

Attempt any TWO questions. All questions carry equal marks.         

Q.3

The reactions in which halogen atom of an alkyl halide is replaced by a Nucleophile are called S_N reactions

1. Compare in tabular form, the S_Nl and S_N² reactions
2. What is Orbital hybridization? Explain sp² hybridization in ethene.
3. What is Cannizzaro's reaction? Write its mechanism

Q.4

a)How is Sodium prepared electrolytically by Down's Cell?
b)Slow and continuous eating away of a metal by atmospheric reagents is called corrosion.
   i)How does the electrochemical theory explain the phenomenon of corrosion?
   ii-Why is galvanizing superior to Tin Plating?

Q.5

a)What are Lipids/ Describe the properties of lipids under the following heads
   i- Sponification
   ii- Hardening of oils
b)Quality of water is determined in terms of certain factors Explain
   i)- Boo - Chemical Oxygen Demand (BOO)
   ii)- Chemical Oxygen Demand (COD)
c)Describe the different steps involved in the manufacture of Urea

CHEMISTRY HSSC-II (2012)

• Which metallic oxide has the most basic character?
  A) MgO
  B) BeO
  C) SrO
  D) BaO
  
  
• The anhydride of perchlonric acid is:
  A) ClO₂
  B) Cl₂O₃ 
  C) ClO₃
  D) Cl₂O₂
  
  
• Which of the following minerals does NOT contain aluminium?
  
  A) Cryolite
  B) Mica
  C) Fluorspar
  D) Feldspar

• The shape of [Cu(NH₃)₄]⁺²,  is square planar ( in this complex is
  
  A) sp³ hybridized
  B) sp³d² hybridized
  C) dsp² hybridized
  D) sp³d hybridized

• Which does NOT form oxide on heating?
  
  A) Li₂CO₃
  B) Na₂CO₃
  C) CaCO₃
  D) MgCO₃

• Which order is correct for the boiling points of halogen acids?
  
  A) HF>HI>HBr>HCI
  B) HF>HCI>HBr>HI
  C) HI>HBr>HCI>HF
  D) HF>HBr>HCI>HI
  
  
• Chemical composition of Colemanite is___________:
  A) Ca₂B₆O₁₁.5H₂O
  B) Ca₂B₄O₂5H₂O
  C) Na₂B₄O₂10H₂O
  D) None of these
  
  
• Which of the following nitrates gives dinitrogen oxide ( N₂O) on heating?
  
  A) Ca(NO₃)₂
  B) NaNO₃
  C) NH₄NO₃
  D) Mg(NO₃)₂
  
  
• Propyne reacts with aqueous H₂SO₄ in the presence of HgSO₄ to loin]
  
  A) Acetone
  B) 1-Propanol
  C) 2-Propanol
  D) Acetaldehyde
  
  
• Which of the following IUPAC name is correct?
  
  A) 3-Ethyl-2-methyl pentane
  B) 2-Methyl-3-ethyl pentane
  C) 2-Ethyl-3-methyl pentane
  D) 3-Methyl-2-ethyl pentane

• A hydrocarbon  C₆H₁₂ on Ozonolysis gives only one product, which does NOT give silver mirror test with Tollen's reagent. the hydrocarbon is:
  
  A) 2,3-dirnethy1-2-butene
  B) 2-hexene
  C) 2-methyl-2-pentene
  D) 2,2-dimethyl 2-butene

• Which is a suitable reagent to convert C₂H₅Br to C₂ H₆?
  
  A) Na/alcohol
  B) Alcoholic KOH
  C) Zn+HCl
  D) NaCN+HCl

• Iso-propyl alcohol reacts with acidified potassium dichromate to give _______:
  
  A) Acetaldehyde
  B) Acetic acid
  C) Propionic acid
  D) Acetone

• Heating a mixture of calcium formate and calcium acetate produces:
  
  A) Acetone
  B) Acetic acid
  C) Formaldehyde
  D) Acetaldehyde

• Ethanoic acid can be obtained by the acid hydrolysis of
  
  A) Methyl cyanide
  B) Ethyl cyanide
  C) Ethanol
  D) Methanol

• Which of the following is fluorocarbon plastic?
  
  A) Nylon
  B) Furan
  C) Teflon
  D) Freon
  
  
• In the following sequence of reactions CH₃ CH₂ CH₂ Br ----→A ----→B ----→C . the product ‘C’ is ________:
   The product 'C' is
  
  A) Propene
  B) 2 -Propanol
  C) 1 propanol
  D) Propyne

SECTION - B

2 Attempt any FOURTEEN parts. The answer to each part should not exceed 5 to 6 lines.

• Borax is the salt of tetraboric acid
  a What is the formula of borax?
  b Why is the aqueous solution of borax alkaline
  c  How is borax used as a water softening agent?                           

• One of the features of transition metals is the formation of coloured compounds
  a. Explain why most of transition metal compounds are coloured.
  b.Why are Sc⁺³ and Zn⁺² compounds colourless?

• Give reasons for the following.
  a. PbCl₂, is ionic while PhCl₄ is covalent
  b. Hydration energies are in the order Al₃^{+ > Mg₂+ > Na+}

• Sulphuric acid is an important laboratory reagent.
  a. What happens when sugar crystals are put in conc H₂SO₄ ?
  b. It is used to dry certain gases but cannot be used to dry NH and H₂S gas Explain.

• Write balanced chemical equations for the following when
  a. NaH is treated with water
  b. LiNO₃, is heated
  c. Beryllium is treated with NaOH

• What are disproportionation reactions?
• The reaction of Cl₂ with hot and cold NaOH is an example of disproportionation reaction. Explain your answer with the help of the balanced chemical

• Potassium Dichromate is an oxidizing agent
  • a Draw the structure of dichromate ion
  • b How is chromate ion converted into dichromate ion?
  • c Write a balanced chemical equation for Its oxidizing action on //,S

• a. How is the ozone layer being depleted by CFCs ?
  b. What is the importance of ozone layer?

• Halogens belong to group VIIA of the periodic table
  a. Explain why they are strong oxidizing agent.
  b. Arrange F2, Br, I₂,and Cl₂ in order of increasing oxidizing power.
  c. Is the following reaction feasible or not Explain your answer Cl₂ + 2Br → Br₂ + 2Cl

• Identify each lettered product:
  Image

• Write the structural formula of the following
  a. Maleic anhydride
  b. Crotonaldehyde
  c. Phthalic acid   

• Nylon is a synthetic condensastion polymer.
• a. Define condensation polymerization
• b. Write the structural formula of the monomeric units of Nylon 66
• c. In what way does the structure of Nylon resemble protein?

• How will you convert.
• a Formaldehyde to Acetaldehyde
• n-propyl alcohol to Iso-propyl alcohol

• A hydrocarbon 'A' reacts with hydrogen Iodide to form compound 'B’ which reacts with aqueous
• KOH to give compound 'C’ Oxidation of 'C’ gives acetone What are the structural formulas of 'A’, ‘B’ and ‘C’ Give equations for all reactions.

• What happens when
• a. Ethene is halogenated in an aqueous solution.
  b.Acetic acid is heated with P.0,
• Sodium benzoate is heated with sodalime.
• Amino acids are the budding blocks of protein and exist as Zwitterion

• a What is Zwitter ion? Give an example
• b How are ammo acids prepared by strecker's method?
• c How do Amino acids react with nitrous acid?

• Benzene readily gives electrophilic substitution reactions
  a.What is Friedel Crafts Acylatton?
• Write the mechanism of the formation of benzophenone from benzene.
• Both alkenes and alkynes are unsaturated hydrocarbons
• How will you differentiate between ethene and ethyne? Give your observations with the help of a valid chemical test
• Explain why ethene is more reactive than ethyne
  a) How does ethyne react with ammonia?
  b) What is functional group isomerism?
  c)Write the structural formulas of the functional group isomers having the molecular formula C3H6O.
• Name these isomers by IUPAC system.

SECTION - C

Note:-  Attempt any TWO questions. All questions carry equal marks.                      
Q.3

    Iron is most widely used metal particularly alloyed with other elements in steel

1. What are the chief ores of Iron?                                                         
2. What is wrought Iron? How can it be manufactured from cast Iron?                       
3. Why does damaged tin plated Iron get rusted quickly?                                     
4. Explain the following terms by giving examples                                           

               (i)     Chelates              (ii)    Substitutional Alloys

 Q.4

4 Cyclic structure of benzene was proposed by Kekule

1. What were the arguments which support Kekule structure? Why was his structure ruled out?
2. Explain the concept which correctly describe the structure of benzene                   
3. Explain why benzene is more reactive than ethane but less reactive than ethene Support your answer by giving examples                                                              

 Q.5

5 Cement is an important building material

1. Define Cement. Name the raw materials required for its preparation                        
2. Explain stepwise the manufacture of cement by wet process                               
3. What is meant by the term “setting of cement'? Describe various reactions taking place during setting process.