TYBSc Chemistry Sem 6 T.y.b.sc. I Question Paper PDF 2026 - Mumbai University | munotes

Questions asked in this paper

• (2) Figures to the right indicate full marks

1. Q1 Attempt any three of the following :—
   • (A) Explain the Lindemann’s theory of unimolecular reaction. 5
   • (B) In one flask, 1.88 x molecules of O, per cubic meter are mixed with 5 3.0 x 10'? molecules of H, per cubic meter at 300K. The average molecular diameter of O, and H, gases is 2.9 x Calculate the number of collisions
   • (C) Explain the use of viscometer in the determination of molecular weight of 5
   • (D) If a polymer sample has population as : 5 10 molecules of molecular mass each 5,000 20 molecules of molecular mass each 7,500 25 molecules of molecular mass each 15,000 Calcular number average and weight average molecular weights of this sample
   • (E) Explain the principle and working of NMR spectrometer. 5
   • (F) Explain the terms: (i) Larmor Precession 5
2. Q2 Attempt any three of the following :—
   • (A) Explain the use of glass electrode determination of pH of a solution. 5
   • (B) Describe the experimental method for the determination of the decomposition 5 potential of an electrolyte
   • (C) Define overvoltage. An overvoltage of 0.64V is observed during electrolysis of 5 INH,SO, solution using lead electrodes. What will be the new value of over voltage if current density is increased five times, b = 0.12 V at 298 K. Calculate the value of ‘a’ also
   • (D) Explain with the help of diagram the contruction and working of silicon solar 5
   • (E) Determine the solubility product and solubility of from, the following cell. 5 The emf of the cell at 298 K is 0.450V
   • (F) (i) Derive an expression to show relation between emf of the cellandchangein 3 enthalpy of the cell reaction
   • (ii) Under what conditions, a cell becomes hot or cold during its working. 2
3. Q3 Attempt any three of the following :—
   • (A) What are scintillation counters used for ? Describe the working of scintillation 5 counter with reference to photo multiplier tube
   • (B) Answer the following :—
   • (i) What is meant by artificial radioactivity ? 1
   • (ii) Give an example of artificial radioactivity induced by a—particleas 2
   • (iii) Distinguish between chemical equilibrium and radioactive equilibrium. 2
   • (C) Describe the construction and working of a nuclear power reactor. 5
   • (D) What is meant by tracer technique ? How is it useful to establish mechanism 5 for hydrolysis of ester ?
   • (E) Calculate the decay constant of if 3.0 x g of Rnis in equilibrium 5 with 1.0g of 226 Ra. The decay constant of Rais 1.5 x
   • (F) Define Q-Value and calculate if for the following nuclear reactor. 5
4. Q4 Attempt any three of the following :—
   • (A) State and explain the law of symmetry of crystallography. 5
   • (B) Determine the number of atoms contained within : (i) a simple cubic unit cell, 5
   • (C) The second order reflection maxima from (111) plane of NaCl occurs 5 The density of NaCl is 2.16 x Calculate the wavelength of the X-rays used to obtain the second order reflection
   • (D) Explain :— 5
   • (E) State and explain the postulate of quantum mechanics whichis relatedto 5
   • (F) meant by commutative property of an operator ? If A = Find out whether A and B commute with each other
5. Q5 (A) Choose the correct answer 4 marks
   • (a) A fast reaction is the one whose half-life varies from
   • (i) to
   • (ii) to
   • (iii) to
   • (b) The polydispersity index of a natural polymer is ussually
   • (i) zero
   • (ii) greater than zero
   • (iii) unity
   • (c) Bakelite is an example of
   • (i) natural polymer
   • (d) The total
   • (i) zero
   • (ii) integral
   • (A) State whether True or False :— 4
   • (p) Number average molar mass of a polymer is independent of molecular size
   • (q) Thermo setting plastic can be reshaped and reused
   • (r) Higher the electron density around a proton, higher is the shielding of the
   • (s) The internal energy of activated complex formed durings chemical reaction, is greater than that of reactants as well as products
   • (B) Choose the correct answer :— 4
   • (a) The emf of a cell is 0.6753V at 298K and 0.6915V at 273K. The temperature coefficient of this cell is
   • (ii) x
   • (iii) 6.48 x
   • (b) The thin glass bulb in glass electrode is filled with
   • (ii) 0.1 MHCI saturated with AgCl
   • (iii) 0.1 MHCI saturated with Hg,Cl,
   • (c) For sponteneous cell reaction
   • (d) The cell Hg,Cl, [KCI || H,Q, Q, used for titrating acid V/s base such that the pH at equivalence point is 7. The potential of quinhydrone electrode is if EQ=0.699V
   • (ii) 0.0424
   • (iii) 0.0424
   • (B) State whether True or False :— 4
   • (p) The ratio of quinone to hydroquinone is unity in quinhydrone
   • (q) The quinhydrone electrode can be used in non-aqueous medium The minimum external potential that must beapplied to an electrolytic cell to bring about continuous electrolysis is called overvoltage
   • (s) Fuel cells are used in space missions
   • (C) Choose the correct answer :— 4
   • (a) When undergoes n) reaction, the recoil nucleus (ii)
   • (b) To sustain a fission reaction, the multiplication factor K should be
   • (i) greater than unity
   • (ii) less than unity
   • (iii) Zero
   • (c) The oxygen liberated during photosynthesis 6CO, + 6H,O C,H,,0, + 60, t
   • (ii) H,O
   • (iii) both CO, and H,O
   • (d) Anthracene acts as
   • (i) phosphor
   • (ii) moderator
   • (iii) Coolant
   • (C) State whether True or False :— 4
   • (p) Radioactive equilibrium is affected by temperature and presure
   • (q) is fissile material
   • (r) Threshold energy is calculated for endoergic nuclear reactions
   • (s) Boron and cadmium are used to prepare control rods
   • (D) Choose the correct answer :— 3
   • (a) If weiss indices of a plane are , the Miller indices of this plane
   • (ii) 4:3:0
   • (iii) 2:3:0 A simple cubic crystal has planes of symmetry
   • (ii) 6
   • (iii) 3
   • (c) 8e** is an eigen function of the operator d/dx, the eigen value is
   • (ii) 4
   • (iii) 4x
   • (D) State whether True or False :— 3
   • (p) There are and per unit cell of NaCl crystal
   • (q) The interplanar distance ratio for simple cubic crystal is
   • (r) The condition f(x)+ g(x)|= 4 4 g(x) is fulfilled by
   • (i) Momentum operator

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