PSEB CLASS 12 CHEMISTRY SAMPLE PAPER SEPTEMBER EXAM 2024

PSEB CLASS 12 CHEMISTRY SAMPLE PAPER SEPTEMBER EXAM  2024

Class-10+2 Paper Chemistry  : 3 hrs. MM 70 

 Section - (A)

Each question carries 1 mark. Multiple choice questions. (28x1=28)
(1) Which of the following is independent of temperature? 

(a) Molarity 

(b) Molality 

(c) Normality 

(d) None of these

(2) Which of the following is an example of liquid solid type of solution 

(a) Alloy

(b) Amalgam 

(c) Adsorption 

(d) None of these

 (3) The normality of 2m  HNO₃, solution will be 

(a) 2

(b) 1

(c) 3

(d) 4

(4) How many colligative properties are there? 

(a) One

(b) Two 

(c) Three

(d) Four

(5) Which battary is used in inverters?

(a) Dry cell 

(b) Lead storage

(c) Nickel cadmium

(d) None of these

(6) Which of the following is Primary cell?

(a) Dry cell 

(b) Mercury cell

(c) Both (a) & (b)

(d) None

(7) The units of resistance are 

(a) Ohm 

(b) Ohmcm⁻¹   

(c) Ohm⁻¹ 

(d) None of these

(8) The units of zero order reaction are
(a) Mol l⁻¹ s⁻¹ 

(b) Mol⁻¹ ls⁻¹  

(c) s⁻¹ 
(d) None of these

(9) SOCl₂ →SO₂ + Cl₂ is an example of 

(a) First order

(b) Second order

(c) Zero order 

(d) None of these

10 ) For which order reactions, order and molecularity are not equal? 

(a) Zero order 

(b) First order 

(c) Second order

(d) None

(11) Which orbitals have diffused shapes?

(a) s

(b) p

(c) d-orbital 

(d) f-orbitals

(12) Which of the following have exceptional configurtion?

(a) Cu 

(b) Cr 

(c) Both (a) & (b)

(d) Zn

(13) Which of the following have highest magnetic moment? 

(a) Ni²⁺

(b) Cu²⁺

(c) Mn²⁺

(d) Co²⁺

(14) Which of the following is colourless? 

(a) Zn²⁺

(b) Cu⁺

(c) Sc³⁺

(d) All of these 

(15) The ligand which has two donor sites is called. 

(a) Monodentate 

(b) Bidentate 

(c) Polydentate 

(d) None of these

(16) The ion present outside the square bracket is called 

(a) Legand 

(b) Contral metal atom

(c) Counter ion 

(d) None 

(17) Identify the following reaction.

CH₃Br +2Na + CH₃Br →   CH₃ - CH₃+ 2NaBr

(a) Sandmeyers 

(b) Gatteronans 

(c)  Groov's  

(d) None of these

(18)  the following reaction:-
CH₃CH₂Br +NaI   → ?^   CH₃CH₂I +NaBr 

(a) Dry Ether 

(b) Ni

(c) AlCl₃

(d) None of these

Carbohydrates are defined as optically active polyhydroxy aldephydes and polyhydroxy ketones. Some of the carbohydrates which are sweet in taste are called sugar i.e. sucrose and sugar present in milk e.g. Glucose, fructose and cane sugar. Carbohydrates are classified as monosaccharides, oligosccharides, polysaccharides. Examples of polysaccharides are cellulose starch and glycogen. etc sugars are soluble in water.

(19) Define Carbohydrates. 

(20) What are sugars?

(21) Name the classes of carbohydrates. 

(22) Write the examples of polysaccharides 

(23) Sugars are___  in water. 

True/False:-

(24) We can separate the components of azeotropic mixtures 

(25) Nickel cadmium is primary battery.

(26) Decompositin of NH₃ is zero order reaction. 

(27) CN is ambidentate ligand.

(28) The size of second and third transition series are almost equal due to lanthanoid contraction.

Section - (B)
Two mark questions. (2 x 10= 20) 

2. Which out of molarity and molality is affected by temperature and why?

3. Concentrated sulphuric acid has density 1.9 g/ml and is 99% H₂SO₄, by weight, calculate molarity.

OR

Which solution will be more concentrated 1 molar  or 1 molal and why?

4. Define  Ideal and non Ideal solution.

5. Give one example of zero order reaction. 

6. Differentiate molecularity and order of reaction.   

OR

The rate constant for a first order reaction is 60s. How much time will it take to reduce the concentration of the reactant to 1/10th of its initial value.

7. Zn²⁺ is not considered as transition element, explain. 

8. Define monodentate and bidentate ligands with example. 

OR

Name the following coordination compound Na[Au (CN)₂] , 

9. Out of Cut and Cu²⁺, which is colourful and why? 

10. What is the role of unhydrous ZnCl₂, while preparing haloalkanes from alcohols. 

11. Define Order of reaction.

OR

Prove that osmotic pressure is a colligative property.

Three marks questions. (3 x 5 = 15) 
Section - (C)

12. Differentiate between positive and negative deviations.

OR

Calculate the vapour pressure of an aqueous solution containing 5% by mass of urea (NH₂CONH₂) at 298 K. The vapoour pressure of water at 298 k is 23.75 mm Hg. 

13. Write the name of cathode, anode, electrolyte used and cell reactions for lead storage battery.

OR

Write Nernst equation and calculate e.m.f of the following cells at 298 K.

Mg(s) /Mg²⁺ (0.001) || Cu²⁺0.001/ Cu(s) 

Given E° Mg²⁺/Mg= -2.37 V, E°Cu²⁺/Cu = 0.34 V. 

14. Why do transetion element form complexes?

15. Why do we prefer SOCl₂ method for the preparation of haloalkanes from alcohols?

Five marks questions.   (5x2=10)
Section - (D)

16. Define First order reaction? For a first order reaction, show that time required for 99% completion is twice the time required for the comletion of 90% of reaction.

(1) Groov's process (ii) Williamson's synthesis (iii) Fittig reaction (iv) Wurtz fittig (v) Mendius

17. (a) What is lanthanoid contraction? Write its cause and consequencies. 

(b) Write the general configuration of f-block elements.

OR

(a) Compare the chemistry of lanthanoids and actinoids 

(b) Which two elements shows oxidation state of +2.