2nd PUC Chemistry Answers - March 2023 Board Exam | Karnataka board - Pdf

 2nd PUC Chemistry exam which took on 14 March 2023 by GOVT OF KARNATAKA'S Answers paper or Scheme of Evaluation paper is released by GOVT OF KARNATAKA.

For some questions in chemistry paper there are grace marks also given. Higher application type of question marks should be allotted for any options. 

Answers:

PART-A:

1) Which kind of defect is introduced by doping intrinsic semiconductors?

a) Dislocation defect                        b) Electronic defect

c) Interstitial defect                         d) Schottky defect

Ans: Option b) OR Electronic defect   OR    Option c) Or Interstitial defect

2) A binary liquid mixture that forms maximum boiling azeotrope at a specific composition

is

a) Ethanol + Water b) n - Hexane + n- Heptane

c) Benzene + Toluene d) Nitric acid + Water

Ans: Specific composition 68%Nitric acid and 32%H2O is not mentioned to get

maximum boiling point azeotrope. For any option marks should be allotted

3) The value of van’t Hoff factor (i) for ethanoic acid in benzene is nearly 

a) 2 b) 1 c) 0.5 d) 0 

Ans: Option c) OR 0.5 OR 1/2

4) On charging the Lead storage battery, PbSO4 on cathode is converted into

a) PbO2      b) Pb        c) PbO      d) No change

Ans:   Option   a) OR PbO2    OR    option b) or Pb 

5)

In the Arrhenius equation the factor e^-Ea/RT

corresponds to

a) Collision frequency

b) Proper orientation

c) The fraction of molecules with kinetic energy > Ea

d) Threshold energy

Ans: Option c) OR The fraction of molecules with kinetic energy >Ea

6) Which one of the following is not applicable to the phenomenon of adsorption?

a) ΔG = −Ve             b) ΔS = −Ve

c) ΔH = −Ve             d) ΔH = +Ve

Ans: Option d) OR ΔH = + Ve

7) What is the role of NaCN in the separation of ZnS and PbS by froth floatation method?

a) depressant          b) froth stabilizer         c) collector         d) reductant

Ans:   Option a) OR Depressant

8) On complete hydrolysis of XeF6 with water, the product formed is

a) XeF4        b) XeO3           c) XeO2 F2       d) XeOF4

Ans:  Option b)  OR   XeO3    

9) Which of the following element is not regarded as transition element?

a) Fe      b) Mn          c) Sc     d) Zn

Ans:   Option d)  Or   Zn

10) M C− bond in metal carbonyls possesses ______________________.

a) Ionic character             b) Both  and  characters

c)  − character only      d) Ion-dipole forces

  Ans:   Option b) OR Both  and  characters 1  

11) Identify chiral molecule in the following compounds.

a) 2- Bromobutane        b) 1-Bromobutane

c) 2- Bromopropane      d) 2-Bromo-2-methyl-Propane

Ans: The given particular options are not discussed under chiral concept in NCERT text

book. For any option marks should be allotted

12) When CH3ONa reacts with (CH3)3CBr, it gives exclusively

a) t- Butylmethyl ether        b) 2,2-Dimethyl propane

c) 2- Methyl propene          d) 2-Methyl Propan -2-ol

Ans: Since it is higher application type of question marks should be allotted for any options. 

13) Iodoform reaction with NaOI can be used for the detection of the compound

a) C2 H5 COC2H5           b) CH3CHO

c) CH3CH2CH2OH        d) (CH3)3COH

Ans: The given options are not discussed under iodoform reaction concept in NCERT text

book. For any option marks should be allotted

14) Nitration of aniline in the strongly acidic medium at 288 K yields

a) 2,4,6 – Trinitroaniline         b) o and p – Nitroanilines

c) m- Nitroaniline                  d) o, m, and p – Nitroanilines

Ans: Option a ) OR 2,4,6 – Trinitroaniline

Option b) OR o and p – Nitroanilines

Option c) OR m- Nitroaniline

Option d) OR o, m, and p – Nitroanilines

15) Which hormone is an iodinated derivative of amino acid tyrosine?

a) Insulin             b) Epinephrine          c) Thyroxin                d) Glucagon

Ans: Option c)  OR    Thyroxin

II. Fill in the blanks by choosing the appropriate word from those given in the

brackets:

[Radium -226, Anoxia, Norethindrone, Pseudo first order, Diphenyl]              5*1=05

16) Because of low concentration of O2 in the blood and tissues of people living at high

altitudes, suffer from a disease called ________

Ans: Anoxia

17) Inversion of cane sugar is an example of ___________________ reaction.

Ans: Pseudo first order

18) Radon is obtained as a decay product of ________________.

Ans: Radium -226

19) When Chlorobenzene is treated with sodium in dry ether ___________ is formed.

Ans: Diphenyl

20) ______________ is a synthetic progesterone derivative, most widely used as an

antifertility drug.

Ans: Norethindrone

 

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