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SCIENCE- Class X Sample Case Studies
- Read the following and answer any four questions from 1.1 to 1.5: Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings. 1.1 The substance not likely to contain CaCO 3 is a) Dolomite b) A marble statue c) Calcined gypsum d) Sea shells. 1.2 A student added 10g of calcium carbonate in a rigid container, secured it tightly and started to heat it. After some time, an increase in pressure was observed, the pressure reading was then noted at intervals of 5 mins and plotted against time, in a graph as shown below. During which time interval did maximum decomposition took place? a) 15-20 min b) 10-15 min c) 5-10 min d) 0-5 min 1.3 Gas A, obtained above is a reactant for a very important biochemical process which occurs in the presence of sunlight. Identify the name of the process - a) Respiration b) Photosynthesis c) Transpiration d) sphotolysis
1.4 Marble statues are corroded or stained rain water. Identify the main reason a) decomposition of calcium carbonate to calcium oxide b) polluted water is basic in nature hence it reacts with calcium carbonate c) polluted water is acidic in nature he d) calcium carbonate dissolves in water to give calcium hydroxide. 1.5 Calcium oxide can be reduced to calcium, by heating with sodium metal. Which compound would act as an oxidizing agent in the above process? a) Sodium b) sodium oxide c) calcium d) calcium oxide Answer Key 1.1 white precipitate is obtained 1.2 0-5 min 1.3 photosynthesis 1.4 polluted water is acidic in nature hence it reacts with calcium carbonate 1.5 calcium oxide
- Read the following and answer any The reaction between MnO 2 with HCl is depicted in the following diagram. It was observed that a gas with bleaching abilities was released. 2.1 The chemical reaction between MnO a) displacement reaction b) combination reaction c) redox reaction d) decomposition reaction. 2.2 Chlorine gas reacts with _______ to form bleaching powder. a) dry Ca(OH) 2 b) dil. solution of Ca(OH) c) conc. solution of Ca(OH) d) dry CaO statues are corroded or stained when they repeatedly come into contact with polluted rain water. Identify the main reason. decomposition of calcium carbonate to calcium oxide polluted water is basic in nature hence it reacts with calcium carbonate polluted water is acidic in nature hence it reacts with calciumcarbonate calcium carbonate dissolves in water to give calcium hydroxide. Calcium oxide can be reduced to calcium, by heating with sodium metal. Which compound would act as an oxidizing agent in the above process? white precipitate is obtained polluted water is acidic in nature hence it reacts with calcium carbonate
Read the following and answer any four questions from 2.1 to 2.5: with HCl is depicted in the following diagram. It was observed that a gas with bleaching abilities was released. The chemical reaction between MnO 2 and HCl is an example of: ecomposition reaction. Chlorine gas reacts with _______ to form bleaching powder. dil. solution of Ca(OH) 2 conc. solution of Ca(OH) 2 when they repeatedly come into contact with polluted Calcium oxide can be reduced to calcium, by heating with sodium metal. Which compound polluted water is acidic in nature hence it reacts with calcium carbonate with HCl is depicted in the following diagram. It was observed that
3 .3 On the basis of evolution/absorption of energy, which of the following processes are similar to combustion of fuel? a) Photosynthesis in plants b) Respiration in the human body c) Decomposition of vegetable matter d) Decomposition of ferrous sulphate. (a) (ii) & (iii) (b) (i) & (ii) (c) (iii) & (iv) (d) (ii) & (i) 3.4 ‘A student while walking on the road observed that a cloud of black smoke belched out from the exhaust stack of moving trucks on the road.’ Choose the correct reason for the production of black smoke: a) Limited supply of air leads to incomplete combustion of b) Rich supply of air leads to complete combustion of fuel. c) Rich supply of air leads to a combination reaction. d) Limited supply of air leads to complete combustion of fuel. 3 .5 ‘Although nitrogen is the most abundant gas in the atmosphere, it does not combustion’. Identify the correct reason for this statement. a) Nitrogen is a reactive gas b) Nitrogen is an inert gas c) Nitrogen is an explosive gas d) Only hydrocarbons can take part in combustion Answer Key 3.1-(d) 3.2-(c) 3.3-(a) 3.4-(a) 3.5-(b)
- Read the following and answer any four questions from Frothing in Yamuna: The primary reason behind the formation of the toxic foam is high phosphate content in the wastewater because of detergents used in dyeing industries, dhobi ghat Yamuna's pollution level is so bad that parts of it have been labelled 'dead' as there is no oxygen in it for aquatic life to survive. .3 On the basis of evolution/absorption of energy, which of the following processes are similar Photosynthesis in plants human body Decomposition of vegetable matter Decomposition of ferrous sulphate. student while walking on the road observed that a cloud of black smoke belched out from the exhaust stack of moving trucks on the road.’ Choose the correct reason for the production Limited supply of air leads to incomplete combustion of fuel. Rich supply of air leads to complete combustion of fuel. Rich supply of air leads to a combination reaction. Limited supply of air leads to complete combustion of fuel. .5 ‘Although nitrogen is the most abundant gas in the atmosphere, it does not combustion’. Identify the correct reason for this statement. Nitrogen is a reactive gas Nitrogen is an inert gas Nitrogen is an explosive gas Only hydrocarbons can take part in combustion ****** Read the following and answer any four questions from 4.1 to 4.5: The primary reason behind the formation of the toxic foam is high phosphate content in the wastewater because of detergents used in dyeing industries, dhobi ghats and households. Yamuna's pollution level is so bad that parts of it have been labelled 'dead' as there is no oxygen .3 On the basis of evolution/absorption of energy, which of the following processes are similar student while walking on the road observed that a cloud of black smoke belched out from the exhaust stack of moving trucks on the road.’ Choose the correct reason for the production .5 ‘Although nitrogen is the most abundant gas in the atmosphere, it does not take part in The primary reason behind the formation of the toxic foam is high phosphate content in the s and households. Yamuna's pollution level is so bad that parts of it have been labelled 'dead' as there is no oxygen
4.1 Predict the pH value of the water of river Yamuna if the reason for froth is high content of detergents dissolved in it. a) 10- b) 5- c) 2- d) 7 4.2 Which of the following statements is correct for the water with detergents dissolved in it? a) low concentration of hydroxide ion (OH-^ )and high concentration of hydronium ion (H 3 O
) b) high concentration of hydroxide ion (OH
- )and low concentration of hydronium ion (H 3 O
) c) high concentration of hydroxide ion (OH-) as well as hydronium ion (H 3 O+) d) equal concentration of both hydroxide ion (OH-) and hydronium ion (H 3 O+). 4.3 The table provides the pH value of four solutions P, Q, R and S Solution pH value P 2 Q 9 R 5 S 11 Which of the following correctly represents the solutions in increasing order of their hydronium ion concentration? a) P>Q>R>S b) P>S>Q>R c) S Answer Key 5.1 b) B 5.2 b) its non-renewable 5.3 (b) Waste water feed → digester → biogas → biogas storage → generator 5.4 (c) (iii) and (iv) 5.5 (d) presence of water and absence of air
- Read the following and answer the questions any four from (i) to (v) Food chains are very important for the survival of most species. 6.1 If 10,000 J solar energy falls on green plants in a terrestrial ecosystem, what percentage of solar energy will be converted into food energy? a) 10,000 J b) 100 J c) 1000 J d) It will depend on the type of the terrestrial plant. 6.2 If Ravi is consuming curd/yogurt for lunch , which trophic level in a food chain he should be considered as occupying? a) First trophic level b) Second trophic level c) Third trophic level d) Fourth trophic level 6.3 The decomposers are not included in the food chain.The correct reason for the same is because decomposers: a) Act at every trophic level of the food chain b) Do not breakdown organic compounds c) Convert organic material to inorganic forms d) Release enzymes outside their body to convert organic material to inorganic forms 6.4 Matter and energy are two fundamental inputs of an ecosystem. Movement of a) Energy is bidirectional and matter is repeatedly circulating. b) Energy is repeatedly circulation and matter is unidirectional. c) Energy is unidirectional and matter is repeatedly circulating. d) Energy is multidirectional and matter is bidirectional.
6.5 Which of the following limits the number of trophic levels in a food chain? a) Decrease in energy at higher trophic levels b) Less availability of food c) Polluted air d) Water Answer Key 6.1 b) 100 J 6.2 c) Third Trophic level 6.3 a) Act at every trophic level of the food chain 6.4 c) Energy is unidirectional and matter is repeatedly circulating 6.5 a) Decrease in energy at higher trophic level
- Read the following and answer the questions any four from (i) to (v) Observe the food web and answer the questions given below - 7.1 The mussel can be described as a) Producer b) Primary consumer c) Secondary consumer d) decomposer 7.2 Which trophic level is incorrectly defined? a) Carnivores – secondary or tertiary consumers b) Decomposers – microbial heterotrophs c) Herbivores – primary consumers d) Omnivores – molds, yeast and mushrooms 7.3 The given figure best represents: a) Grassland food chain b) Parasitic food chain c) Forest food chain d) Aquatic food chain
8.2 Recycling of paper is a good practice but recycled paper should not be used as food packaging because a) recycled papers may release color /dyes on food items b) recycled papers are not absorbent c) recycled papers can cause infection due to release of methane d) recycled papers are costly 8.3 According to the ‘Solid Waste Management Rule 2016’, the waste should be segregated into three categories. Observe the table below and select the row that has correct information Wet waste Dry waste Hazardous waste a) Cooked food, vegetable peels Used bulbs, fluorescent lamps Plastic carry bags, bottles, newspaper, cardboard b) Coffee and tea powder, garden waste Plastic carry bags, bottles, newspaper, cardboard Expired medicines, razors, paint cans c) Leftover food, vegetable peels Coffee and tea powder, garden waste Insect repellents, cleaning solutions d) Uncooked food, tea leaves Old crockery, frying pans Coffee and tea powder, garden waste 8.4 Effective segregation of wastes at the point of generation is very important. Select the appropriate statements giving the importance of waste segregation. i) less waste goes to the landfills ii) better for public health and the environment iii) help in reducing the waste iv) resulting in deterioration of a waste picker’s health a) both i) and ii) b) both i) and iii) c) both ii) and iii) d) both i) and iv) 8.5 When recycling a plastic water bottle, what should you do with the cap? a) The cap goes into a garbage can and the bottle goes in a recycling bin b) Screw the cap back on the bottle, then put the bottle and cap in a recycling bin c) Screw the cap back on the bottle, then put the bottle and cap in the garbage can d) Recycle the cap separately. Answer Key 8.1 – d 8.2 -c 8.3 -b 8.4 -a 8.5 -.a
- Read the following and answer any FOUR questions from 9.1 to 9.5 that follow on the basis of information provided and studied concepts. In Kunjpura village, located in Karnal district, Haryana, AdityaAggarwal and his older brother AmitAggarwal run Tee Cee Industries, a steel plant set up by their ancestors in 1984. Along with this, they also run a gaushala that houses 1,200 cows that can no longer produce milk.
The cow shelter was manageable but running the steel plant was turning out to be expensive becau they spent a whopping Rs 5 lakh every month on electricity. The brothers struck upon an idea. Why not run the factory with the biogas produced from cow dung from the shelter and other gaushalas, along with bio and agri led Aditya and Amit to start AmritFertilisers, a biogas project, in 2014, without any government support. 9 .1 Biogas is a mixture of the following gases. (a) Ethane,Carbon monoxide, Nitrogen and Butane (b) Methane,Hydrogen,Carbon dioxide and Nitrogen (c) Butane,Carbon monoxide,Propane and Hydrogen (d) Carbon monoxide,Sulphur dioxide and Hydrogen 9 .2 Raw material used in bio gas plant is (a) Animal dung (b) crop residue (c) Food waste (d) All of the above 9 .3 The correct labelling in a biogas plant is given in (a) A- Manure B- (b)A- Slurry B-Digester (c) A-Gas tank B-Manure (d) A- Digester B-Gas tank 9 .4 Biogas is a better fuel than animal dung cake because (i) Biogas has lower calorific value. (ii) Animal dung cake has higher calorific value. (iii) Biogas has high heating capacity. (iv) Biogas burns without smoke. (a) (i) only (b) (ii) only (c) (iii) and (iv) (d) (i) and (ii) The cow shelter was manageable but running the steel plant was turning out to be expensive becau they spent a whopping Rs 5 lakh every month on electricity. The brothers struck upon an idea. Why not run the factory with the biogas produced from cow dung from the shelter and other gaushalas, along with bio and agri-waste like sewage, farm waste, etc led Aditya and Amit to start AmritFertilisers, a biogas project, in 2014, without any government .1 Biogas is a mixture of the following gases. Ethane,Carbon monoxide, Nitrogen and Butane Methane,Hydrogen,Carbon dioxide and Nitrogen Carbon monoxide,Propane and Hydrogen Carbon monoxide,Sulphur dioxide and Hydrogen .2 Raw material used in bio gas plant is .3 The correct labelling in a biogas plant is given in slurry C-Gas tank D-Digester Digester C-Manure D- Gas tank Manure C-Digester D- Slurry Gas tank C-Slurry D-Manure. .4 Biogas is a better fuel than animal dung cake because calorific value. Animal dung cake has higher calorific value. Biogas has high heating capacity. Biogas burns without smoke. The cow shelter was manageable but running the steel plant was turning out to be expensive because The brothers struck upon an idea. Why not run the factory with the biogas produced from cow dung waste like sewage, farm waste, etcThis led Aditya and Amit to start AmritFertilisers, a biogas project, in 2014, without any government
10.3 The decomposers are not included in the food chain. The correct reason for the same is because decomposers: a) Act at every trophic level of the food chain b) Do not breakdown organic compounds c) Convert organic material to inorganic forms d) Release enzymes outside their body to convert organic material to inorganic forms 10.4 Matter and energy are two fundamental inputs of an ecosystem. Movement of a) Energy is bidirectional and matter is repeatedly circulating. b) Energy is repeatedly circulation and matter is unidirectional. c) Energy is unidirectional and matter is repeatedly circulating. d) Energy is multidirectional and matter is bidirectional. 10.5 Which of the following limits the number of trophic levels in a food chain? a) Decrease in energy at higher trophic levels b) Less availability of food c) Polluted air d) Water Answer Key 10.1 b) 100 J 10.2 c) Third Trophic level 10.3 a) Act at every trophic level of the food chain 10.4 c) Energy is unidirectional and matter is repeatedly circulating 10.5 a) Decrease in energy at higher trophic level
- Read the following and answer the questions any four from (i) to (v) Biosphere is a global ecosystem composed of living organisms and abiotic factors from which they derive energy and nutrients. And ecosystem is defined as structural and functional unit of the biosphere comprising of living and non-living environment that interact by means of food chains and chemical cycles resulting in energy flow, biotic diversity and material cycling to form a stable, self-supporting system 11.1 Which trophic level is incorrectly defined? a) Carnivores – secondary or tertiary consumers b) Decomposers – microbial heterotrophs c) Herbivores – primary consumers d) Omnivores – molds, yeast and mushrooms 11.2 The diagram below shows a food web from the sea shore
The mussel can be described as a) Producer b) Primary consumer c) Secondary consumer d) Decomposer 11.3 The given figure best represents: a) Grassland food chain b) Parasitic food chain c) Forest food chain d) Aquatic food chain 11.4 Consider the following statements concerning food chains: (i) Removal of 80% tigers from an area resulted in greatly increased growth of vegetation (ii) Removal of most of the carnivores resulted in an increased population of herbivores. (iii) The length of the food chains is generally limited to 3 – 4 trophic levels due to energy loss (iv) The length of the food chains may vary from 2 to 8 trophic levels Which two of the above statements are correct? a) (i), (iv) b) (i), (ii) c) (ii), (iii) d) (iii), (iv) 11.5 Which of the following group of organisms are not included in ecological food chain? a) Carnivores b) Saprophytes c) Herbivores d) Predators Answer Key 11.1 d) Omnivores – molds, yeast and mushrooms 11.2 c)Secondary consumer 11.3 a) Grassland food chain 11.4 c) (ii), (iii)
- 5 b) Saprophytes
12.5 The given graph shows the amount of waste generated, dumped and treated in percentage. Identify the reason of low success rate of waste management process. a) only 15% of urban India’s waste is processed b) less than 60% of waste is collected from households c) more than 60% of waste is collected from households d) both a and b Answer Key 12.1 (d) 12.2 (c) 12.3 (b) 12.4 (a) 12.5 (d) The given graph shows the amount of waste generated, dumped and treated in percentage. Identify the reason of low success rate of waste management process. ly 15% of urban India’s waste is processed less than 60% of waste is collected from households more than 60% of waste is collected from households
The given graph shows the amount of waste generated, dumped and treated in percentage. Identify
