CBSE Class 10 Science Chapter Wise Important Case Study Questions PDF Download

For CBSE Class 10 students preparing for the upcoming board exams, particularly in Science, it is essential to focus on important case study questions. The CBSE Class 10 Science board exam for 2023 is scheduled to take place on March 4, following the overall CBSE Board exam starting on February 15th. As the exam date draws near, students are putting in extra effort to cover the remaining syllabus, address weak areas, and revise important questions from previous year papers and practice materials. To assist CBSE Class 10 Science students in their preparation, we have compiled Chapter Wise Case Study Questions in a PDF format. By solving these questions, students can effectively review their understanding and assess their readiness for the upcoming board exam in 2023.

Why are CBSE Class 10 Science Case Study Questions Important?

As per the latest question paper design for CBSE Class 10 Science, the distribution of questions in the upcoming CBSE Class 10 Science board exam in 2023 will be as follows:

• Section A: This section consists of 20 Multiple Choice Questions (MCQs) carrying 1 mark each.
• Section B: This section includes 6 Very Short Answer type questions carrying 2 marks each. The answers to these questions should be within the range of 30 to 50 words.
• Section C: This section contains 7 Short Answer type questions carrying 3 marks each. The answers to these questions should be within the range of 50 to 80 words.
• Section D: This section comprises 3 Long Answer type questions carrying 5 marks each. The answers to these questions should be within the range of 80 to 120 words.
• Section E: This section consists of 3 Case Based/Source Based units of assessment, each carrying 4 marks. Each unit may have sub-parts to be answered.

As stated earlier, the Case Based Questions in the CBSE Class 10 Science exam will contribute a total of 12 marks, which is approximately 15 percent of the overall marks. Hence, it is crucial for all CBSE Class 10 students to thoroughly practice the important case study questions from the Science syllabus. This will help them enhance their preparation and perform well in the exam.

How to solve case study questions in CBSE Class 10 Science?

• Carefully read the provided case and the accompanying questions.
• Pay close attention to the questions and carefully analyze their content.
• Utilize your subject knowledge and understanding of theories to determine the appropriate answers based on the given case.

CBSE Class 10 Science Chapter Wise Important Case Study Questions

Q.1. Chemical reactions are a way of representing the transformation of substances through the use of symbols and formulas for reactants and products. There exist different types of chemical reactions, including combination, decomposition, displacement, double displacement, oxidation, and reduction reactions. Exothermic chemical reactions are those in which heat is released during the formation of products. All combustion reactions fall under the category of exothermic reactions.

(i) The powerful force that propels the rocket forward in space is generated as a result of which type of reaction?
(a) Combination reaction
(b) Decomposition reaction
(c) Displacement reaction
(d) Double displacement reaction

(ii) When a white salt is heated, it decomposes to produce brown fumes and leaves behind a yellow residue. The yellow residue is composed of:
(a) Lead nitrate
(b) Nitrogen oxide
(c) Lead oxide
(d) Oxygen gas

(iii) Among the following reactions, which one represents a combination reaction?
(a) CaO (s) + H₂O (l) → Ca (OH)₂ (aq)
(b) CaCO₃ (s) → CaO (s) + CO₂(g)
(c) Zn(s) + CuSO₄ (aq) → ZnSO₄ (aq) + Cu(s)
(d) 2FeSO₄(s) → Fe₂O₃ (s) + SO₂(g) + SO₃(g)

(iv) Complete the following statements by choosing the correct type of reaction for X and Y.
Statement 1: The heating of lead nitrate is an example of 'X' reaction.
Statement 2: The burning of magnesium is an example of 'Y' reaction.
(a) X-Combination, Y-Decomposition
(b) X-Decomposition, Y-Combination
(c) X-Combination, Y-Displacement
(d) X-Displacement, Y-Decomposition

Q.2. The previous understanding of oxidation and reduction was centered around the addition or removal of oxygen or hydrogen elements. In terms of oxygen and hydrogen, oxidation refers to the addition of oxygen to a substance or the removal of hydrogen from a substance. Conversely, reduction involves the addition of hydrogen to a substance or the removal of oxygen from a substance. In an oxidation reaction, the substance that provides oxygen to another substance or removes hydrogen from it is called an oxidizing agent. On the other hand, in a reduction reaction, the substance that provides hydrogen to another substance or removes oxygen from it is referred to as a reducing agent.

(i) In a redox reaction,
(a) both substances are reduced.
(b) both substances are oxidised.
(c) an acid is neutralised by a base.
(d) one substance is oxidised while the other is reduced.

(ii) In the reaction H₂S + Cl₂ ⟶ S + 2HCl,
(a) H₂S is the reducing agent.
(b) HCl is the oxidising agent.
(c) H₂S is the oxidising agent.
(d) Cl₂ is the reducing agent.

(iii) Which of the following processes does not involve either oxidation or reduction?
(a) Formation of slaked lime from quicklime.
(b) Heating mercuric oxide.
(c) Formation of manganese chloride from manganese oxide (MnO₂).
(d) Formation of zinc from zinc blende.

(iv) Mg + CuO ⟶ MgO + Cu
Which of the following statements is incorrect regarding the above reaction?
(a) CuO gets reduced.
(b) Mg gets oxidised.
(c) CuO gets oxidised.
(d) It is a redox reaction.

Q.3. When a copper vessel becomes tarnished, it develops an oxide layer on its surface. However, by rubbing lemon on the vessel, the surface gets cleaned, and the vessel regains its shine. This is because the acid present in the lemon reacts with the copper oxide to form a soluble salt. When the vessel is washed with water, this salt is removed, along with the layer of copper oxide, exposing the shiny surface of the vessel.

(i) Which acid is found in lemon?
(a) Formic acid
(b) Acetic acid
(c) Citric acid
(d) Hydrochloric acid

(ii) What is the nature of copper oxide?
(a) Acidic
(b) Basic
(c) Neutral
(d) Amphoteric

(iii) What is the name of the salt formed in the above reaction?
(a) Copper carbonate
(b) Copper chloride
(c) Copper citrate
(d) Copper citrate

(iv) The process of copper getting tarnished is known as:
(a) Corrosion
(b) Rancidity
(c) Displacement
(d) None of these

Q.4. Metals are widely recognized for their extensive applications in various industries, but non-metals are equally significant. Oxygen, a non-metal present in the air, is crucial for both respiration and combustion. Non-metals have a wide array of compounds that are highly valuable, such as ammonia, nitric acid, sulphuric acid, and more. Unlike metals, non-metals can exist in all three states of matter. Although solid non-metals are expected to be hard, they generally possess low density and brittleness. They also exhibit low melting and boiling points and are poor conductors of electricity.

(i) Among the given options, which non-metal exhibits a lustrous appearance?
(a) Phosphorus
(b) Sulphur
(c) Bromine
(d) Iodine

(ii) Which of the following substances is referred to as the 'King of chemicals'?
(a) Urea
(b) Ammonia
(c) Sulphuric acid
(d) Nitric acid

(iii) Which of the following non-metals is in a liquid state?
(a) Carbon
(b) Bromine
(c) Iodine
(d) Sulphur

(iv) Hydrogen finds applications in which of the following?
(a) Synthesis of ammonia
(b) Synthesis of methyl alcohol
(c) Nitrogenous fertilizers
(d) All of the above

Q.5. Nisha noticed that the bottoms of her cooking utensils were becoming black while the flame on her stove appeared yellow. Her daughter recommended cleaning the air holes of the stove to achieve a clean, blue flame. She also explained that this would help conserve fuel.
(i) Determine the causes of the formation of a sooty flame on the stove.
(ii) Is it possible to differentiate between saturated and unsaturated compounds based on their combustion? Provide a justification for your answer.
(iii) What is the reason behind the change in flame color to blue after cleaning the air holes of the stove?

Q.6. Blood serves the purpose of transporting food, oxygen, and waste materials within our bodies. It is composed of plasma, which acts as a fluid medium. The heart, a pumping organ, is responsible for propelling the blood throughout the body. The blood follows a specific path and direction as it passes through the chambers of the heart. As it circulates throughout the body, blood applies pressure against the walls of the blood vessels.

(i) The left atrium receives oxygenated blood from the lungs through the
(a) Vena cava
(b) Pulmonary artery
(c) Pulmonary vein
(d) Aorta

(ii) The flow rate of blood in capillaries is typically low because capillaries are
(a) Very narrow and offer high resistance
(b) Wide and offer low resistance
(c) Very narrow and offer low resistance
(d) Wide and offer high resistance

iii. Which of the following statements are true about the human heart?
(a) It is a hollow muscular organ.
(b) It is a four-chambered organ with three auricles and one ventricle.
(c) It has separate chambers to prevent oxygen-rich blood from mixing with carbon dioxide-containing blood.
(d) Both A and C

(iv) Examine the table below and select the row that provides accurate information.
(a) Blood = Plasma + RBC + WBC + Platelets
(b) Plasma = Blood - RBC
(c) Lymph = Plasma + RBC
(d) Serum = Plasma + RBC + WBC

Q.7. At the Allen Institute for Brain Science, there is an exhibit featuring a human brain. Despite being a jelly-like mass of fats and tissues weighing around three pounds (1.4 kilograms), the human brain stands as the most intricate living structure known to us. Its complexity surpasses that of any other structure in the universe. Comprised of glia and neurons, the brain consists of billions of these two fundamental types of cells. Neurons are particularly remarkable due to their branch-like projections known as axons and dendrites, which play a vital role in gathering and transmitting electrochemical signals. Various types of glial cells serve to protect neurons and maintain the overall health of the brain. Together, this intricate network of cells gives rise to every aspect of our shared humanity. Without the brain, essential functions such as breathing, playing, loving, and remembering would not be possible.

(i) While animals like elephants, dolphins, and whales may possess larger brains, humans have the most developed cerebrum. Our cerebrum is highly folded, densely packed within our skulls. What is the reason behind the high folding of our brain?

(ii) Among the following options, which is not a function of the cerebrum?
(a) Speech
(b) Learning
(c) Posture
(d) Emotion

(iii) Which of the following protects our brain?
(a) Neurotransmitter
(b) Cerebrospinal fluid
(c) Meninges
(d) Grey matter

(iv) Ram was studying in his room when suddenly he detected a burning smell and noticed smoke filling the room. He quickly left the room. Was Ram's action voluntary or involuntary? Why?

Q.8. Preeti has a strong passion for gardening and maintains various flowering plants in her garden. On a particular day, some mischievous children entered her garden and plucked several leaves from a Bryophyllum plant, scattering them around the garden. After a few days, Preeti noticed the emergence of new Bryophyllum plants from the fallen leaves on the ground.

(i) What does the incident described in the paragraph indicate?
(a) Bryophyllum leaves possess specialized buds that can germinate and give rise to new plants.
(b) Bryophyllum is capable of vegetative propagation through leaves.
(c) Bryophyllum is a flowering plant that reproduces solely through asexual means.
(d) Both (a) and (b) are correct.

(ii) Which of the following plants can undergo vegetative propagation through leaves similar to Bryophyllum?
(a) Guava
(b) Begonia
(c) Ginger
(d) Mint

(iii) Do you think any other vegetative part of Bryophyllum can assist in propagation? If yes, which part?
(a) Roots
(b) Stems
(c) Flowers
(d) Fruits

(iv) Which of the following plants is commonly propagated through stem cuttings in horticultural practices?
(a) Potato
(b) Snake plant
(c) Rose
(d) Water hyacinth

Q.9. The increasing size of the human population is a matter of concern for everyone. The population's size is determined by the rate of births and deaths within it. Reproduction is the biological process through which organisms multiply their population. Sexual maturation, which enables reproduction, occurs gradually alongside overall body growth. However, reaching a certain level of sexual maturation does not necessarily indicate readiness for engaging in sexual activity or raising children. To control population growth, humans utilize various contraceptive methods.

(i) What are common indicators of sexual maturation in boys?
(a) Widening of shoulders
(b) Development of mammary glands
(c) Expansion of waist
(d) Deepening of voice

(ii) Common indicator of sexual maturation in girls is
(a) Deepening of voice
(b) Growth of mustache and beard
(c) Development of mammary glands
(d) Broadening of shoulders

(iii) Which contraceptive method alters the hormonal balance in the body?
(a) Condoms
(b) Diaphragms
(c) Oral contraceptive pills
(d) Both (a) and (b)

(iv) What factors should be maintained for a healthy society?
(a) Birth and death rates
(b) Male and female sex ratio
(c) Child sex ratio
(d) None of the above

Q.10. Pea plants exhibit two possible seed types: smooth seeds and wrinkled seeds. One of these phenotypes is entirely dominant over the other. A farmer makes the choice to cross-pollinate a flower from a plant with smooth seeds using pollen from a plant with wrinkled seeds. As a result, the pea pod that develops from this pollination contains only smooth seeds.

(i) Which of the following conclusions can be inferred?
(1) The allele for smooth seeds is dominant over the allele for wrinkled seeds.
(2) The plant with smooth seeds is heterozygous.
(3) The plant with wrinkled seeds is homozygous.
(a) 1 only
(b) 1 and 2 only
(c) 1 and 3 only
(d) 1, 2, and 3

(ii) Which of the following crosses will result in smooth and wrinkled seeds in equal proportion?
(a) RR X rr
(b) Rr X rr
(c) RR X Rr
(d) rr X rr

(iii) Which of the following crosses can be used to determine the genotype of a plant with a dominant phenotype?
(a) RR X RR
(b) Rr X Rr
(c) Rr X RR
(d) RR X rr

(iv) When two heterozygous smooth-seeded plants (Rr) are crossed, a total of 1000 plants were obtained in the F1 generation. What will be the respective number of smooth and wrinkled seeds obtained in the F1 generation?
(a) 750 smooth, 250 wrinkled
(b) 500 smooth, 500 wrinkled
(c) 800 smooth, 200 wrinkled
(d) 950 smooth, 50 wrinkled