Halogen Derivatives and Alcohol, Phenol, Ether

 Pathak’s Academy Spectrum 2024

Topics: Chapters 10,11

Marks: 25                                                                                                                 Time: 1h 

                                                                         Section - A

Q.No. 1 : Select and write the correct answer (any 5) [05]

i) Which of the following is used as source of dichlorocarbene

a. Tetrachloromethane b. Chloroform c. iodoform d. DDT

ii) Resorcinol on distillation with zinc dust gives

A. Cyclohexane B. Benzene C. Toluene D. Benzene-1, 3-diol

iii) The best method for preparation of alkyl fluorides is

a.Finkelstein reaction b.Swartz reaction c.Free radical fluorination d. Sandmeyer's reaction

iv) Identify the chiral molecule from the following.

a. 1-Bromobutane b. 1,1- Dibromobutane c. 2,3- Dibromobutane d. 2-Bromobutane

v) Anisole on heating with concentrated HI gives

A.Iodobenzene B.Phenol + Methanol

C. Phenol + Iodomethane D.Iodobenzene + methanol

vi) Ethers are kept in air tight brown bottles because

A. Ethers absorb moisture B. Ethers evaporate readily

C. Ethers oxidise to explosive peroxide D. Ethers are inert

vii) Choose the compound from the following that will react fastest by SN1mechanism.

a. 1-iodobutane b. 1-iodopropane c. 2-iodo-2 methylbutane d. 2-iodo-3-methylbutane

Section - B

Attempt any 5 [5 x 2 = 10 M]

i) Haloarenes are less reactive than halo alkanes.give reason

ii) Hydroboration-oxidation of propene gives.....

iii) Write structure of optically active alcohol having molecular formula C4H10O

iv) Arrange the following in the increase order of boiling points

a. 1-Bromopropane b. 2- Bromopropane c. 1- Bromobutane d.1-Bromo-2-methylpropane

v) Distinguish between - SN1 and SN2 mechanism of substitution reaction ?

vi) Explain why phenol is more acidic than ethyl alcohol.

                                                      

                        Section - C

Attempt any Two. [3 x 2 = 6 M]

i)Write structural formulae for

a. 3-Methoxyhexane b. Methyl vinyl ether c. 1-Ethylcyclohexanol

ii) Match the pairs.

        Column I                Column II

a. CH3 CH-CH3            i. vinyl halide

             X     

b. CH2=CH-CH2X       ii. alkyl halide

c. CH2=CH-X              iii. allyl halide

                                    iv. benzyl halide

                                    v. aryl halide

iI) Explain why p-nitrophenol is a stronger acid than phenol.

iii)  Convert the following.

i. Propene to propan-1-ol ii. Benzyl alcohol to benzyl cyanide iii. Ethanol to propane nitrile

 

Section - D

Attempt any One. [1 x 4 = 4 M]

i)  Give the reagents and conditions necessary to prepare phenol from

a. Chlorobenzene b. Benzene sulfonic acid.

ii) Give the equations of the reactions for the preparation of phenol from isopropyl

benzene.

 

12 th Chemistry: CHEMICAL THERMODYNAMICS

 Pathak's Academy Spectrum 2022

CHEMICAL THERMODYNAMICS

Section A (any 7)(7M)

1. Internal energy of a system of a molecule is determined by

A) Kinetic energy B) Vibrational movement C) Rotational movement D) All of these

2. In the reaction C + O2 → CO2 + Heat. The ΔH is A) Maximum B) Minimum C) Negative D) Positive.

3. Which of the following relationship is correct A) H=U-PV B) H=U+P+V C) H= U+PV D) H=-U+PV

4. For an ideal gas the relationship between internal energy change and enthalpy change is A) ΔH=U.PV B) ΔU=ΔH+P. ΔV C) ΔH=U-P. ΔV D) ΔH=ΔU+ΔNrt

5. The enthalpies of all elements in their standard states are A) Unity B) Zero C) Less than Zero D) Different for each element

6. All irreversible processes are A) Non-spontaneous B) In equilibrium C) Isothermal D) Spontaneous

7. An endothermic reaction is allowed to takes place rapidly in air. The temperature of the surrounding air A) Increases B) decreases C) Remains same D) Cannot be predicted

8. Which of the following process is reversible A) Evaporation of water at 100oC and 1atm pressure B) Melting of ice at 10oC C) Mixing of two gases by diffusion D) Non of these

9. ΔU of combustion of methane is –x KJ mol-1. The value of ΔHo is A) Equal to ΔU B) Greater than ΔU C) Less than ΔU D) Equal to zero

Q2 Define (4M)

a) Enthalpy b) Enthalpy of fusion c) Enthalpy of vaporization d) Enthalpy of atomization e) Enthalpy of ionization

Section B

I) What is Entropy? Describe with example (2M)

II) State Third law of Thermodynamics (2MSSection C 

(Any 3)(3X3= 9M)

I) Obtained relationship between ΔH and ΔU for reaction 

II)Define and explain Enthalpy of sublimation with example                         

III) Derive relationship between Bond enthalpy and enthalpy of a chemical reaction

IV) State Hess’s law of constant heat summation with eg.

Chemistry chapter 1 Solid State

 

Test on Solid State

20 Marks Time: 45 min

Q.no.1) Multiple choice question                        of  3M

i) In body centered cubic structure the space occupied is about         a) 68%    b) 53%    c) 38%    d) 32%

ii) Close packing is maximum in the crystal lattice of     a) Simple cubic    b) Face centered     c) body centered    d) none 

iii) The major binding force in diamond is     a) Covalent bond    b) ionic bond    c) metallic bond     d) co-ordinate covalent bond

Section B

Q.No.2) Solve any Two                     4M

i) Differentiate between tetrahedral and octahedral voids.

ii) A compound is formed by two elements M and N. The elements N formed ccp and atoms of M occupy 1/3rd of tetrahedral voids. What is the formula of the compound?

iii) Explain Schottky defect with example.

Section C

Q.No.3) Solve any Three                  9M

i) Explain defects in crystal structure.

ii) Differentiate between Crystalline and Amorphous solids

iii) Differntiate p and n types of conductors.

iv) The edge length of the unit cell of Ta, is 330.6 pm; the unit cell is body-centered cubic. Tantalum has a density of 16.69 g/cm³.

(a) calculate the mass of a tantalum atom.
(b) Calculate the atomic weight of tantalum in g/mol.

Section D

Q.No. 4) Solve any One                 4M

i) Derive expression for Density of Simple cubic and Body centered cell.

ii) Give seven systems of crystal lattice with their edge length and angle specifications.

Physics paper 12th : Topics: Chapters 10 to 13

 Pathak’s Academy Spectrum 2024

Topics: Chapters 10,11,12,13..

Marks: 30                                                                                                Time: 1h 10 min 

Section - A

Q.No. 1 : Select and write the correct answer (any 6) [06]

i) A conducting thick copper rod of length 1 m carries a current of 15 A and is located on the Earth's equator. There the magnetic flux lines of the Earth's magnetic field are horizontal, with the field of 1.3 × 10-4 T, south to north. The magnitude and direction of the force on the rod, when it is oriented so that current flows from west to east, are

(A) 14 × 10-4 N, downward.

 (B) 20 × 10-4 N, downward.

 (C) 14 × 10-4 N, upward.

 (D) 20 × 10-4 N, upward. 

ii) A charged particle is in motion having initial velocity v when it enters into a region of uniform magnetic field perpendicular to v. Because of the magnetic force the kinetic energy of the particle will

 (A) remain uncharged.(B) get reduced(C) increase. (D) be reduced to zero.

iii) Soft iron is used to make the core of transformer because of its

 (A) low coercivity and low retentivity 

 (B) low coercivity and high retentivity

 (C) high coercivity and high retentivity 

(D) high coercivity and low retentivity 

iv) Which of the following statements is correct for diamagnetic materials?

 (A) µr < 1 (B) χ is negative and low 

(C) χ does not depend on temperature (D) All of above

v) A circular coil of 100 turns with a cross-sectional area (A) of 1 m 2 is kept with its plane perpendicular to the magnetic field (B) of 1 T. What is the magnetic flux linkage with the coil?

 (A) 1 Wb (B) 100 Wb(C) 50 Wb (D) 200 Wb

vi) A current through a coil of self inductance 10 mH increases from 0 to 1 A in 0.1 s. What is the induced emf in the coil? 

 (A) 0.1 V (B) 1 V (C) 10 V (D) 0.01 V

vii) In an AC circuit, e and i are given by e = 150 sin(150t) V&i = 150 sin(150 t + π/3 ) A. the power dissipated in the circuit is 

 (A) 106 W (B) 150 W (C) 5625 W (D) Zero

viii) In a series LCR circuit the phase difference between the voltage and the current is 450. Then the power factor will be  (A) 0.607 (B) 0.707 (C) 0.808 (D) 1

Q. 2 Answer the following. [04]

i) Which property of soft iron makes it useful for preparing electromagnet?

ii) State Lenz’s law in the light of the principle of conservation of energy.

iii) Calculate the SI unit of Inductance.

iv) Draw the phasor diagram for purely capacitive ckt.

Section - B

Attempt any 5 [5 x 2 = 10 M]

i) Obtain and expression for orbital magnetic moment of an electron rotating 

about the nucleus in an atom.

ii)  What are eddy currents? State applications of eddy currents

iii) Explain why the inductance of two coils connected in parallel is less than the inductance of either coil.

iv) Discuss the Curie law for paramagnetic material.

iv) What do you mean by electromagnetic induction? State Faraday’s law of induction.

v) Compare between resistance and reactance.

vi) If the rms current in a 50 Hz AC circuit is 5A, the value of the current 1/300 seconds after its value becomes zero is?

Section - C

Attempt any Two. [3 x 2 = 6 M]

i) A toroid of narrow radius of 10 cm has 1000 turns of wire. For a magnetic field 

of 5 × 10-2 T along its axis, how much current is required to be passed through 

the wire?

ii) Explain Faraday's Laws of Electromagnetic Induction. Deduce equation for EMF

iii) Deduce the average Power equation for LCR ckt with ckt diagram

  

Section - D

Attempt any One. [1 x 4 = 4 M]

i) Explain Self and Mutual Induction Derive the equation for both with a diagram.

ii) What is Resonance ckt? Deduce the expression for series and parallel resonant circuit with their characteristics .Explain Q factor with the help of diagram.