SAMPLEPAPERS
November 12, 2025
Pseb board most important sample papers chemistry
Pseb board most important sample papers
Studypur Sample paper
Class12
Chemistry
Time Allowed:3hours Maximum Marks: 70 SECTION- A (Each carry one Marks)
Multiple Choice Questions : 1)Which of the following is not correct for ideal solution:
a) △Smixing b) △Vmixing c) △Hmixing d) It obeys roults law
2)What will be the molalality of a solution having 18 g of glucose dissolved in 500g of water :
a) 1m b) 0.5m c) 2m d) 0.2m
3) Which of the following will have highest boiling point:
a) 0.1M NaCl b) 0.1M BaCl2 c) 0.1M glucose d) 0.1 sucrose
4)Units of molar conductivity are :
a) S cm mol-¹ b) S cm²mol-¹ c) S cm³mol-¹ d) S cm²mol-²
5) Units of rate constant for third order reaction are :
a) sec b ) mol lit sec c) mol lit sec d) mol lit sec
6) Which of the following methods cannot produce aldehydes ?
a) Oxidation of primary alcohols b)Dehydrogenation of secondary alcohols
c) Ozonolysis of alkenes d) Hydration of ethyne with acid
7) Which of the following required in stephen reaction :
a) LiCl b) NiCl2 c) SnCl2 d) TiCl4
8) Acetyl chloride reacts with 'X' to give butane -2-one
a) Cadmium Chloride b) methyl magnesium chloride
c) dimethyl Cadmium d) diethyl Cadmium
9) When benzene diazonium chloride is treated with copper powder and HCl, the product
formed is :
a) chlorobenzene b) toluene c) phenol d) aniline
10)The co- ordination number of M in [M(en)2Cl2] Cl is
a) 6 b) 9 c) 8 d) 10
True/ False :
11) In coordination compound metal shows only primary valency .
12) Carboxylic acids are weaker acids than alcohols .
13 ) Hypo solution is used in photography because it is strong complexing agent .
14) Phenetole reacts with HI at 373K to give ethanol and iodobenzene .
15) Carboxylic acid turn blue litmus red .
Read the passage and Answer the Questions ( 16) to( 20 ):
Starch is a polymer of alpha glucose and major reserve food in plants, turns blue with iodine. It is a mixture of two components (i) amylose (20%), an unbranch polymer water soluble (ii) amylopectin (80%), a branched polymer water insoluble. Source of starch are potatoes, wheat, rice, maize, bananas etc.
Cellulose is the most abundant and structural polysaccharides a plants. It is important food source of some animal. It is polymer of D(+)-glucose.
The chief sources of cellulose are wood( contains 50% cellulose rest being Lignin, resins etc) and cotton ( contains 90% cellulose rest being fats and waxes)
Q-16 What are components of starch ?
Q-17 What are the chief source of cellulose?
Q-18 Which components of starch turn blue with iodine?
Q-19 Name the component of starch whose percentage is more in it ?
Q-20 What are the sources of starch?
Section-B ( each carry marks )
3. Calculate the boiling point of the solution containing 1.8g of a non volatile solute dissolved in 90 g of benzene. The boiling point of pure benzene is 353.23K. kb = 2.53 K kg mol‐¹, molar mass of solute 58 g mol-¹.
Or
When 1.80 gm of non volatile compound is dissolved in 25 g of acetone , the solution boils at 56.86 C while pure acetone boils at 56.38⁰ C under the same atmospheric pressure calculate the molar mass of the compound. Kb for the acetone is 1.72 k kg mol-¹.
4. Specific conductance of 0.12 N solution of an electrolyte is 2.4 x 10-² S cm‐¹.Calculate equivalent conductance.
5. What is corrosion? Discuss mechanism of rusting of iron.
6. A first order reaction takes 20 min for 25% decomposition. Calculate the time when 75% of the reaction will be completed?
Or
For first order reaction show that time required for 99% completion is twice the time required for completion of 90% of reaction.7.Give difference between order and molecularity.
8.Why d-block elements form number of alloys ?
9.Write four difference between coordination compound and double salt.
10. (a) Define ligand.
11. Why Phenols are more acidic than Alcohols?
Or
Write Victor Meyer’s test to distinguish between 1º, 2º and 3º alcohols?
12. Why aldehydes are more reactive than ketones?
Or
Write a note on Wolf Kishner reduction.13. Write a note on Gabriel Phthalimide synthesis.
14. Explain the following reactions :
(a) Diazotisation
(b) Hoffmann’s bromamide reaction
15. Write four difference between globular and fibrous proteins.
Section -C (each carry 3 marks)
16. Write the nernst equation. Calculate the emf of the following at 298 K.
Cu (s)/Cu+²(0.130 M) || Ag+(0.0001 M)/Ag
Ecu²+/Cu= +0.34 V and EAg+/Ag =+0.80 V
Or
The molar conductance at infinite dilution for Nal, CH3COONa and ( CH3COO)2Mg are 10.59, 7.10 and 16.58 Scm² mol‐¹ respectively at 298 K. Calculate the molar conductance of Mgl² at infinite dilution.17. The rate of reaction quadruples when temp changes from 293 K to 313K. Calculate the activation energy of the reaction.
18. How will you differentiate between primary, secondary and tertiary alcohols on the basis of Lucas test.
Or
How will you prepare t-butyl ethyl ether by using Williamson’s s synthesis .SECTION-D (EACH CARRY FIVE MARKS)
20. (i) Write a note on preparation of KMnO4 from pyrolusite.ii) Why d-block elements act as good catalysts?
Or
i)Write four differences between Lanthanides and Actinide ii) Why d-block elements show variable oxidation states ?
iii) Draw the structure of Cr O²‐ ion.
21. Write a note on following reactions :
1) Sandmeyer reaction.
2 )Wurtz reaction
3)Wurtz fitting reaction
4)Balz schiemann reaction
5)Finkelstein reaction
Or
a)Why alkyl halides are more reactive than aryl halides towards nucleophilic substitution reactions.b) Why alkyl halides are insoluble in water ?
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