Class X SCIENCE PWT-1 QUESTION PAPER

CHEMISTRY -13 MARKS

1. The chemical reaction between Hydrogen sulphide and iodine to give Hydrogen iodide and Sulphur is given below:            H₂S + I₂ → 2HI + S                                 

The reducing and oxidizing agents involved in this redox reaction are:                         1

A) Iodine and Sulphur, respectively 

B) Hydrogen Sulphide and Iodine respectively 

C)Sulphur and iodine, respectively 

D)Hydrogen sulphide and Sulphur, respectively                 

2.What type of reaction is an exothermic reaction?              1

a) Decomposition reaction  

b) Displacement reactions  

c) Combustion reaction  

d) Redox reaction 

3. One of the following does not happen during a chemical reaction. This is:   1

(a) Breaking of old chemical bonds and formation of new chemical bonds. 

(b) Formation of new substances with entirely different properties. 

(c) Atoms of one element change into those of another element to form new products. 

(d) A rearrangement of atoms takes place to form new products. 

4. An acid which can decolorize purple colored potassium permanganate solution is:        1

(a) sulphuric acid                                      

(b) citric acid 

(c) carbonic acid                                       

(d) hydrochloric acid 

5. Assertion (A): Fe₂O₃ + 2Al ------> Al₂O₃ + 2Fe 

The above chemical equation is an example of a displacement reaction.                      1

Reason (R): IRON is more reactive than ALUMINIUM, Produces IRON metal from its oxide. 

a) Both A and R are true and R is the correct explanation of A. 

b) Both A and R are true but R is not the correct explanation of A. 

c) A is true but R is false. 

d) A is false but R is true  

6.  A) Why is silver chloride stored in dark bottles?                                                 2

B) What happens when blue colored crystals of copper sulphate are heated? 

7.What is a chemical equation? Describe one activity each to show that a chemical change has occurred in which (i) change of color ,and (ii) change in temperature has taken place                      2

8. A solution of a substance 'X' is used for testing carbon dioxide. Identify 'X'. What will be its reaction with carbon dioxide? Write a balanced equation for the reaction        2

9. When lead nitrate is heated strongly in a boiling tube, two gases are liberated (with brown fumes), and a yellow solid residue is left behind in the test tube:                   (3)

I) Name the type of chemical reaction and define it. 

II) Write the name and formula of the colored gas liberated. 

III) Write the balanced chemical equation for the reaction.  

Biology (13 marks)

Section A: Multiple Choice Questions (MCQs) (1 mark each)

    1.     Which of the following is not a function of chlorophyll in the process of photosynthesis?

     a)     Absorbing sunlight

 b)    Splitting water molecules

c)     Forming glucose

d)    Increasing the temperature of the leaf

     2.     In human beings, where does the process of digestion of starch begin?  

      a)     Stomach

      b)    Mouth

      c)     Small intestine

      d)    Large intestine

    3.     What is the role of the enzyme pepsin in the stomach?

     a)     It digests proteins

     b)    It digests fats

     c)     It digests carbohydrates

     d)    It emulsifies fats

     Section B: Assertion and Reasoning (1 mark each)

For question numbers 5, 6 two statements are given- one is Assertion (A)and the other

is Reason (R). Select the correct answer to these questions from the options A, B, C, D as given

below: -

A Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

B Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion

C Assertion is true, but Reason is false

D Assertion is false, but Reason is true.

4.     Assertion (A): The process of nutrition in plants is called photosynthesis.

Reason (R): Plants take in carbon dioxide from the air and water from the soil to make their food in the form of glucose.

5.     Assertion (A): The human stomach has a highly acidic environment.

Reason (R): The acidic environment helps in killing harmful bacteria and activates pepsin for protein digestion.

Section C: Case Study-based Question (4 marks)

Case Study:

Rhea is a student who is learning about human nutrition. During a class, her teacher explained how the digestive system breaks down food and absorbs nutrients. Rhea learned that the mouth, stomach, and small intestine play key roles in digestion. She also discovered that enzymes like amylase, lipase, and pepsin help break down complex substances into simpler ones.

1.     Based on this case, answer the following questions:

      a)     What is the role of amylase in the digestive process?

      b)    Why is it important for the small intestine to have a large surface area?

      c)     What happens in the stomach during digestion?

      d)    How does the absorption of nutrients take place in the small intestine?

      Section D: Long Answer Questions (2 marks each)

      2.     Explain the process of protein digestion in human beings.

      3.     What is dark reaction?

Physics (13 marks)

Section A – 1 Mark Each (3× 1 = 3 )

Q1. Define the radius of curvature of a spherical mirror.

Q2. What is the nature of the image formed by a concave mirror when the object is placed at infinity?

Q3. Write the relationship between focal length and radius of curvature of a spherical mirror.

 

Section B – 2 Marks Each (3 × 2 = 6 Marks)

Q5. Draw a ray diagram to show image formation by a concave mirror when the object is placed at the focus.

Q6. List two uses of concave mirrors based on their image-forming properties.

Q7. An object is placed 20 cm in front of a concave mirror of focal length 10 cm. Find the position of the image using the mirror formula. (Give proper signs)

 

Section C – Case Study Based Question (1 × 4 = 4 Marks)

Read the following case and answer the questions:

Rita was getting ready for a function. She stood close to her makeup mirror and observed a large, erect image of her face. Curious, she slowly moved away from the mirror and noticed that the image became inverted and smaller. Her brother explained that the mirror behaves differently depending on how close or far the object is.

Q8.1 What type of mirror is used in the makeup mirror?

Q8.2 What is the nature of the image formed when Rita is very close to the mirror?

Q8.3 What happens to the image when Rita moves beyond the center of curvature?

Q8.4 Why is this type of mirror suitable for use as a makeup mirror?

Class XII CHEMISTRY chapter 1, 2, 3 AND 4 PRACTICE PAPER

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CLASS –XII   SUBJECT: CHEMISTRY (UT-1, 2, 3 AND 4)   PRACTICE PAPER

TIME: 3 hr  

MAXIMUM MARKS: 70

NOTE: All questions are compulsory

MCQs Section A

Q1 The value of van’t Hoff factor for ethanoic acid in benzene is (a) 1.0 (b) 1.5 (c) 0.5 (d) 2

 Q2 Which of the following aqueous solutions should have the highest boiling point? (a) 1.0 M NaOH (b)      1.0 M Na2SO4 (c) 1.0 M NH4NO3 (d) 1.0 M KNO3

Q3 In comparison to a 0.01 M solution of glucose, the depression in freezing point of a 0.01 M MgCl2      solution is _____________.(a) the same (b) about twice (c) about three times (d) about six times

Q4 If we place the blood cells in a solution containing less than 0.9% (m/V) sodium chloride. They would     swell. This is because (a) the solution is hypotonic (b) the solution is isotonic (c) the solution is      hypertonic (d) none of these

Q5 The positive value of the standard electrode potential of Cu2+/Cu indicates that ______________.  (a) this redox couple is a stronger reducing agent than the H+ /H2 couple. (b) this redox couple is a stronger oxidising agent than H+ /H2. (c) Cu can displace H2 from acid. (d) Cu cannot displace H2 from acid

Q6 On increasing temperature, (a) ionic conductance increases and electronic conductance decreases. (b) ionic conductance decreases and electronic conductance increases. (c) both ionic and electronic       conductance increase. (d) both ionic and electronic conductance decrease

Q7 Charge carried by 1 mole of electrons is    (a) 6.023 × 1023 coulomb (b) 9.65 × 104 coulomb (c) 1.6 ×       10–19 coulomb  (d) 6.28 × 1019 coulomb

Q8 Which of the following is a zero order reaction? (a) Decomposition of N2O5 (b) Decomposition of     NH3 (c) Decomposition of N2O (d) Radioactive decay of unstable nuclei

Q9 The half life of a first order reaction is 69.35 sec.      The value of rate constant of the reaction is (a)       1.0 s–1 (b) 0.1 s–1 (c) 0.01 s–1 (d) 0.001 s–1

Q10 The magnetic moment is associated with its spin angular momentum and orbital         momentum.        Spin only magnetic moment value of Cr3+ ion is ____________. (a) 2.87 B.M. (b) 3.87 B.M. (c) 3.47         B.M. (d) 3.57 B.M.

Q11 Transition elements show magnetic moment due to spin and orbital motion of electrons. Which of        the following metallic ions have almost same spin only magnetic moment?  (a)       Co2+    (b) Cr2+          (c) Mn2+ (d) Cr3+

Q12 The electronic configuration of Cu(II) is 3d 9 whereas that of Cu(I) is 3d10. Which of the following is correct? (a) Cu(II) is more stable (b) Cu(II) is less stable (c) Cu(I) and Cu(II) are equally stable (d) Stability of Cu(I) and Cu(II) depends on nature of copper salt

Assertion-Reason Questions In the following questions, two statements are given—one labeled Assertion (A) and the other labeled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:

(a) Both Assertion (A) and Reason (R) are correct statements, and Reason (R) is the correct explanation of the Assertion (A).

(b) Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the correct explanation of the Assertion (A).

(c) Assertion (A) is correct, but Reason (R) is incorrect statement.

 (d) Assertion (A) is incorrect, but Reason (R) is correct statement

Q13 Assertion (A) : Zn, Cd and Hg cannot be regarded as transition elements. .

       Reason (R) : These  elements do not belong to the d-block of the periodic table.

Q14 Assertion (A) : Rusting of iron is quicker in saline water than in ordinary water.

         Reason (R) : Salt water helps in flow of current in the miniature cell developed on the iron surface.

Q15 Assertion (A) : Order of the reaction can be zero or fractional.

        Reason (R) : We cannot determine  order from balanced chemical equation.

Q16 Assertion (A) : The solubility of a gas in a liquid increases with increase of pressure.

         Reason (R) : The solubility of a gas in a liquid is directly proportional to the pressure of the gas.

EACH QUESTION CARRY 2 MARKS  (12) SECTION B

Q17 Define Molecularity of a Reaction  and pseudo order reaction  with examples

Q18  Units of Zero order reaction and first order of reaction

Q19 A solution of Ni(NO3)2 is electrolysed between platinum electrodes using  a current of 5 amperes for 20 minutes. What mass of Ni is deposited at the cathode?

Q20  Discuss the  Variation of Conductivity and Molar Conductivity with Concentration

Q21.  State Henry’s law and mention some important applications?

Q22 Based on solute-solvent interactions, arrange the following in order of increasing solubility in n-octane and explain. Cyclohexane, KCl, CH3OH, CH3CN.

EACH QUESTION CARRY3 MARKS (18) SECTION C

Q23 What is meant by positive and negative deviations from Raoult's law and how is the sign of ΔmixH related to positive and negative deviations from Raoult's law.

Q24 The vapour pressure of pure liquids A and B are 450 and 700 mm Hg respectively, at 350  K . Find out the composition of the liquid mixture if total vapour pressure is 600 mm Hg. Also find the composition of the vapour phase.

Q25 Describe the preparation of potassium dichromate from iron chromite ore. What is the effect of increasing pH on a solution of potassium dichromate? Or

How does the acidified permanganate solution react with (i) iron(II) ions (ii) SO2and (iii) oxalic acid? Write the ionic equations for the reactions.

Q26 Give examples and suggest reasons for the following features of the transition metal chemistry:

(i)The lowest oxide of transition metal is basic, the highest is amphoteric/acidic.

(ii)A transition metal exhibits highest oxidation state in oxides and fluorides.

(iii) The highest oxidation state is exhibited in oxoanions of a metal.

Q27 (i) State two advantages of H2—O2 fuel cell over ordinary cell

(ii) What type of a battery is lead storage battery? Write the anode and cathode reactions and the overall cell reaction occurring in the operation of a lead storage battery

Q28 i) Calculate ∆r G° for the reaction        Mg(s) + Cu2+(aq)                 Mg2+(aq) + Cu(s) Given: Eo cell = +2.71 V, 1 F = 95600 C mol–1 (ii) Name the type of cell which was used in Apollo space programme for providing electrical power.

EACH QUESTION CARRY 4 MARKS (9)  SECTION D

Q29 The d-block elements are those elements in which the last electron enters the d-subshell of the penultimate shell. The general electronic configuration of these elements is (n – 1) d1–10 ns 1–2, where n is outermost shell. The d-block consisting of groups 3–12 occupies the large middle section of the periodic table. The elements of d-block are also known as transition elements as they possess properties that are transitional between the s and p block elements. A transition element is defined as an element which has incompletely filled d-orbitals in its ground state or any one of its oxidation states. There are four series of transition elements spread between group 3 and 12. First transition series or 3d-series: Scandium (21Sc) to Zinc (30Zn), Second transition series or 4d-series: Yttrium (39Y) to Cadmium (48Cd), Third transition series or 5d-series: Lanthanum (57La) and Hafnium (72Hf) to Mercury (80Hg) (Omitting 58Ce to 71Lu), Fourth transition series or 6d-series: Begins with Actinium (89Ac) is still incomplete.

In what way is the electronic configuration of transition elements different from that of the nontransition elements?

2. Why is zinc not regarded as a transition clement?

3. Why does a transition series contain 10 elements?

4. Name the element which shows outer electronic configuration 3d3 4s 2

5. What are interstitial compounds?

Q30 A solution which obeys Raoult’s law strictly is called an ideal solution, while a solution which shows deviations from Raoult’s law is called a non-ideal solution or real solution. Suppose the molecules of the solvent and solute are represented by A and B respectively, and let gAB, gAA and gBB are the attractive forces between A—B, A—A and B—B respectively. An ideal solution of the components A and B is defined as the solution in which the intermolecular interactions between the components A—B are of the same magnitude as the intermolecular interactions found in the pure components A—A and B—B. Similarly,a non- ideal solution of the components A and B is defined as the solution in which the intermolecular interactions between the components A—B are of the different magnitude as the intermolecular interactions found in the pure components A—A and B—B.

 1. What type of liquids form the ideal solution?

2. Give one example of an ideal solution.

 3. Write two characteristics of non-ideal solution

4. On mixing liquid A and liquid B, volume of the resulting solution decreases, what type of deviation from Raoult’s law is shown by?

EACH QUESTION CARRY 5 MARKS (15) SECTION E

Q31 (i) Define the following terms: (a) Azeotrope (b) Osmotic pressure (c) Colligative properties (ii) Calculate the molarity of 9.8% (w/w) solution of H2SO4 if the density of the solution is 1.02 g mL–1. (Molar mass of H2SO4 = 98 g mol–1)

Q32 i) State Kohlrausch law of independent migration of ions. Write an expression for the molar conductivity of acetic acid at infinite dilution according to Kohlrausch law. (ii) Calculate  for acetic acid. Given that   (HCl) = 426 S cm2 mol–1,  (NaCl) = 126 S cm2 mol–1   (CH3COONa) = 91 S cm2 mol–1

Q33 (i)The rate constant for a first order reaction is 60 s –1. How much time will it take to reduce the initial concentration of the reactant to its 1/16th value?

(ii) A reaction is first order in A and second order in B. (i) Write the differential rate equation. (ii) How is the rate affected on increasing the concentration of B three times? (iii) How is the rate affected when concentration of both A and B are doubled?

Class IX science PWT -1 question paper sample

CHEMISTRY 13 MARKS

Case-Based Questions (QN 1-4) ​4

Rohan was observing his mother making tea. He noticed that when sugar was added to the hot milk, it dissolved quickly even without stirring. He also observed that the aroma of the hot tea spread throughout the room.

1. What characteristic of particles of matter allows sugar to dissolve in milk?

2. What phenomenon is responsible for the aroma of hot tea spreading in the room?

3. Name one factor that affects the rate of this phenomenon.

4. If the tea was cold, would the sugar dissolve faster or slower?

5. Explain why a gas can be easily compressed but a solid cannot.​​​​2

6. Describe an activity to show that particles of matter have spaces between them.​2

7. Convert the following temperatures: 2

a) 300 K to Celsius scale 

b) 50°C to Fahrenheit scale  

8. Explain the relationship between density, mass, and volume. A metal block has a mass of 150 kg and a volume of 0.05 m³. Calculate the density of the metal.​3

Biology 14 MARKS

9. The nucleus of the cell was discovered by-

(a) Robert Hooke    (b)  Robert Cook      

(c) Robert Brown   (d) Lueenhooke        [1]

10. The substance present in cell wall of plant and fungi cells are-

(a) Protein and Lipid respectively            

(b) Cellulose and Chitin respectively

(c)Chitin and Cellulose respectively       

(d) Cellulose and Pepditoglycan respectively​  [1]

11. The plasma membrane of a cell is 

(a) Impermeable         

(b) Permeable   

(c) Semi permeable  

(d) None of these         ​​[1]

12. consists of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:​​​​​​​​1

(a) Both A and R are true and R is the correct explanation of A.

b) Both A and R are true but R is not the correct explanation of A.​

(c) A is true but R is false

​(d) A is false but R is true

Assertion: The cell is structural unit of life.

Reason: Cell is smallest unit  capable of performing all the functions necessary for life.

13. Why do cells of multicellular organisms attain various shapes and sizes?                                   [2]

14. Who first proposed cell theory ? Who modified it? State the cell theory statement.                     [3]

15..The diagram of plant cell is given below. Study the structure and answer the question follows