Chemistry
(Objective) 2012
(Inter-I)
Note:- You have four choices for each objective type question as A, B, C and a The choice which you think is correct; fill that circle in front of that question number. Use marker or pen to fill the circles. result in zero mark in that question. Attempt as many questions as given in objective type question paper and leave others blanks. Write the letter A, B, C or D in the column (write correct option) against each question. If there is a contradiction in the bubble and liana written answer, bubble option will be considered correct.

Question#1

• The mass of one mole of electrons is:
  
  (A) 1.008 mg
  (B) 0.55 nig
  (C) 0.184 mg
  (D) 1.673 mg
  
  
• The in largest no. of molecules is present in:
  
  (A) 3.6g of H₂O
  (B) 4.8 g of C₂ H₅ OH
  (C) 2.8 g of CO
  (D) 5.4 g of N₂O₅
  
  
• The comparative rates at which the solute move in paper chromatography, mainly depends on
  
  (A) The site of paper
  (B) The Rf values of solute
  (C) Temperature of experiment
  (D) Size of chromatic used solute experiment tank used
  
  
• Pressure remaining constant at which temperature the volume of gas will become twice of what it is at 0C⁰:
  
  (A) 546 C⁰
  (B) 200 C ⁰
  (C) 546 K
  (D) 273 K
  
  
• The molar volume of CO2 is maximum at:
  
  (A) STP
  (B) 127 C⁰ and 1 atm
  (C) 0C⁰ and 2.0 atm
  (D) 273 C⁰ and 2.0 atm
  
  
• When water freeze at 0C⁰, ifs density decreases due to:
  
  (A) Cubic structure of ice
  (B) Empty spaces present in the structure of ice
  (C) Change of bond length
  (D) Change of bond ice angle
  
  
• Which the following is Pseudo solid
  
  (A) Ca F₂
  (B) Glass
  (C) NaCI
  (D) K Br
  
  
• Quantum No value for 2p orbitals are:
  
  (A) n=2, l=1
  (B) n=1, l=2
  (C) n=1, l=0
  (D) n=2, l=2
  
  
• Orbitals having same energy are called:
  
  (A) Hybrid orbitals
  (B) Molecular orbitals
  (C) Valence orbitals
  (D) Degenerate orbitals
  
  
• Which of the Hydrogen Halides has the highest percentage of ionic character?
  
  (A) HE
  (B) HBr
  (C) HCI
  (D) HI
  
  
• The no. of bonds in Nitrogen molecule is:
  
  (A) One sigma and one Pi
  (B) One sigma and two Pi
  (C) Three sigma only
  (D) Two sigma and two Pi
  
  
• The net heat change in a chemical reaction is same whether it is brought about in one or more than one steps the law is known as:
  
  (A) Henry's law
  (B) Hess's law
  (C) Charlie’s law
  (D) law of conversation of energy
  
  
• For which system does the equilibrium constant K. has the unit (concentration)^-1:
  
  (A) N₂+3H (Irreversible sign) 2NH₃
  (B) H₂+I₂ (Irreversible sign) 2HI
  (C) 2NO₂ (Irreversible sign) N₂O₄
  (D) 2HF (Irreversible sign) H₂ +F₂
  
  
• A solution of glucose is 10%. The volume is which 1g molt of it i8 dissolved will be
  
  (A) ldm³
  (B) 1.8 dm³
  (C) 200 cm³
  (D) 900 cm³
  
  
• If salt bridge is not used between two half cells, then the voltage
  
  (A) Decreases rapidly
  (B) Decreases slowly
  (C) Does not charge
  (D) Drops to zero
  
  
• Which of the following statements is correct about Galvanic cell.
  
  (A) Anode is negatively charged
  (B) Reduction occurs at anode
  (C) Cathode is positively charged
  (D) Reduction occurs at cathode
  
  
• The unit of rate constant is same as that of rate of reaction in
  
  (A) First order reaction
  (B) Second order reaction
  (C) Zero order reaction
  (D) Third order reaction

SUBJECTVE TYPE

2. Answer briefly any Eight parts from the following:

• Write formulas used for the determination of percentages of C & H by combustion analysis.
• 180 gm of glucose and 342 gm of sucrose have the same no of molecules but different no of atoms present in them. Explain
• Define limiting reactant. How limiting reactant is identified?
• Define crtstallization.
• How come HCI and Kmmou solutions can be filtered by Gooch crucible.
• What is absolute zero? What happens to real gases while approaching it?
• Define pressure, Give its various units.
• Give causes for deviation of gases from ideality.
• Calculate the value of R in SI units.
• Why heat of sublimation is greater than heal of vaporization.
• Inter molecular forces are weaker than intramolecular forces why?
• Define lattice energy. Give example

3. Answer briefly any Eight parts from the followings:.

• Write electronic configuration of an element with atomic number z = 24 z =37
• Define (a) wave length (b) Hind's rule
• What is stark effect.
• Ionization energy decreases down the group in the periodic table. Give reason
• Sigma bond is stronger than pay bond. Why?
• Define the term "Joule" and convert 15 calories to joules.
• Define Enthalpy of neutralization with an example.
• Compare Exothermic and Endothermic reactions,
• Define consulate solution temperature with example.
• What are Azeotropic mixtures?
• Define oxidation reaction with an example.
• Compare order of reaction and molecularity.

4. Answer briefly any Six parts from the Followings:

• Explain that the bond angles of H₂O and NH₃ are not 109.5 like that of CH₄. Although “O" and "N" atoms are Spy hybridized,
• Explain why the melting points, boiling points beat of vaporization and heat of sublimations of electrovalent compounds arc higher than covalent compound.
• Reversible reaction attain the position of equilibrium which is dynamic in nature and not static. Explain it.
• Explain the tons buffer and buffer capacity.
• Define solubility product. Derive solubility product expression forAg₂CrO₄ and PbCl₂
• What are buffer solution? Why do we need them in daily life.
• Na and K can displace hydrogen from acids but Pt, Pd and Cu can not.
• Explain the difference between electrolytic cell and voltaic cell.
• The radioactive decay is always a first Order reaction. Explain.

SECTION -II

Note: Attempt any three questions:
Question#5
(a) i. Define molecular ion with examples.
ii. Differentiate between empirical and molecular formula.
(b) Define liquid crystals. Discuss important uses of liquid crystals.

Question#6
(a) Give important postulate of “VSEPR-TEORY"
(b) When 2.00 moles of H2 and 100 mole of O2 at 100C and 1.00 torr pressure react to produce 2.0 moles of gases water 84.5 kj of energy are evolved, What are.
i) ∆H
(ii) ∆E for production alone mole of 1120(g)?

Question#7
(a) Derive the equation for radius of nth orbit of hydrogen atom using Bohr's model.
(b) One mole of methane gas is maintained at 27C⁰ its volume is 250 Cm³, Calculate the pressure exerted by the as when it is non-ideal.
a= 2.253 atm dm6 mole ^-2
b= 0.0428 dm3 mole^-1

Question#8
(a) Define law of mass action and derive equilibrium constant for a general chemical reaction.
(b) Balance the following equation by oxidation number method.
MnO₂+ HCI → MnCl₂+H₂O+Cl₂

Question#9
(a) Describe the measurement of Roiling Point Elevation by Lands Berger’s method.
(b) Give four characteristics of Enzyme catalysis.