GUJRANWALA BOARD 2017
PAPER CHEMISTRY
PART-2
Time: 20 MM.
(Objective Part)
Marks: 17
Note: You have four choice for each objective type question as A, B, C and D. The choice which you think is correct; fill that circle in front of that question number. Use marker or pen to fill the circles. Cutting or filling two or more circles will result in zero mark in that question.

• Keeping in view the size of atoms, which order is the correct one:

(A) Mg>Sr
(B) Ba< Mg
(C) Lu >Ce
(D) C > I

• Which ion will have maximum value of heat of hydration?

(A) Na⁺
(B) Cs⁺²
(C) Ba⁺²
(D) Mg⁺²

• Tincal is mineral of

(A) A
(B) Si
(C) B
(D) C

• Laughing gas is chemically

(A) NO
(B) N₂O
(C) NO₂
(D) N₂O₄

• The anhydride of HCO₄ is

(A) CO₃
(B) CO₂
(C) C₂O₅
(D) C₂O₇

• Which of the following is a-typical transition metal?

(A) Sc
(B) Y
(C) Ra
(D) Co

• Which set of hybrid orbitals has planar triangular shape?

(A) SP³
(B) SP
(C) SP²
(D) dSP²

• Formula of chloroform is:

(A) CH₃C
(B) CC₄
(C) CH₂C₂
(D) CHC₃

• During nitration of benzene, active nitrating agent is

(A) NO₃
(B) NO₂⁺
(C) NO₂^-
(D) HNO₃

• For which mechanisms, the first step involved is same?

(A) E₁ and E₂
(B) E₂ and SN₂
(C) SN₁ and E₂
(D) E₁ and SN₁

• Which enzyme is not involved in fermentation of starch?

(A) diastase
(B) zymase
(C) urease
(D) invertase

• Formalin is solution of formaldehyde in water

(A) 10%
(B) 20%
(C) 40%
(D) 60%

• Which reagent is used to reduce a carboxylic group to an alcohol?

(A) H₂/Ni
(B) H₂/Pt
(C) NaBH₄
(D) LiA H₄

• Which one of the following elements is not present in all proteins?

(A) Carbon
(B) Hydrogen
(C) Nitrogen
(D) Sulphur

• Ammonium nitrate fertilizer is not used for which crop?

(A) Cotton
(B) Wheat
(C) Sugar cane
(D) Paddy rice

• In purification of potable water the coagulant used is

(A) nickel sulphate
(B) copper sulphate
(C) barium sulphate
(D) alum

• Which of the following derivatives cannot be prepared directly from acetic acid?

(A) Acetamide
(B) Acetyl chloride
(C) Acetic anhydride
(D) Ethyl acetate

GUJRANWALA BOARD 2017
PAPER CHEMISTRY
PART-2
Time: 3:10 Hours
(Subjective Part)
Marks: 83
Section-I

2. Attempt any EIGHT short questions.

2. What is Newlands' law of octaves?
3. Why the second value of electron affinity is positive?
4. Show by chemical equations that BeO is amphoteric.
5. Why is CaCO₂ added in NaC in Downs' cell?
6. Write down chemical reactions involved in borax-bead test.
7. Write down any four uses of aluminum.
8. Conc. H₂S0₄ acts as dehydrating agent. Show it by two reactions.
9. What happens when Cu is treated with dil. HNO₃ and cone. HNO3? Give reactions.
10. What are chelates? Give one example.
11. Why does damaged tin plated iron get rusted quickly?
12. Give any two conditions which cause the formation of smog.
13. What is chemical oxygen demand and how is it determined?

3. Attempt any EIGHT short questions.

1. Give reason that fluorine is gas, iodine is solid.
2. Why oxidizing power of halogens decreases down the group?
3. Define the term carbonization. Indicate three fractions obtained by carbonization of coal.
4. Why there is no free rotation around a double bond but there is around a single bond?
5. How will you prepare following compounds from ethane?
   (a) Ethyl alcohol
   (b) Ethylene epoxide
6. What is raney nickel? How does it convert benzene into cycle hexane?
7. What happens when benzene oxidize with ozone?
8. How will you prepare 2,4, 6 — trinitrotoluene from benzene in two steps?
9. What is meant by - elimination?
10. Give mechanism of E₁ elimination reaction in two steps.
11. What are essential conditions for fermentation?
12. Prepare the following compounds from phenol:
    (a) 2.4. 6 Trinitrophenol\
    (b) benzene

4. Attempt any SIX short questions.

1. Write four uses of acetaldehyde.
2. Convert calcium acetate to acetone.
3. What are zwitter ions? Write its structure.
4. What happens when ammonium acetate is heated?
5. Draw the structures of
   (a) purine
   (b) pyrimidine
6. What happens when the hydrolysis of triglyceride is carried out?
7. How polyester is prepared by condensation polymerization?
8. Write the chemical reactions involved in the preparation of urea.
9. What are the common bleaching agents used in paper industry in Pakistan?
10. Write four uses of acetaldehyde.
11. Convert calcium acetate to acetone.
12. What are zwitter ions? Write its structure.

SECTION-II

Attempt any THREE questions.

5. (a) Define ionization energy. How does it vary in groups and in periods generally in periodic table?
   (b) Write four roles of gypsum in industries.

6. (a) Explain the following with an example:
   (i) ligand
   (ii) co-ordination sphere
   (iii) central metal atom
   (iv) substitutional alloy
   (b) Define smog. Explain pollutants which are the main cause or photochemical smog?

7. (a) Why vital force theory was rejected? What is the importance of wholer’s work in chemistry?
   (b) What are SN-reactions? Explain SN₁ reaction in detail.

8. (a) How will you bring about the following conversions?
   (i) I - butene into I-butyne
   (ii) Acetylene into chloroprene
   (b) By using propanone as a starting material, how would you get?
   (i) acetic acid
   (ii) isopropyl alcohol
   
   
9. (a) What is resonance? Explain structure of benzene by resonance method.
   (b) Write down two methods for preparing phenol. What is the reaction of phenol with
   (i) Zn
   (ii) Br₂ water