ACP Chemistry Practice Questions PDF

ACP AARAMBH CHAPTERWISE PROBLEMS PRASHANT KIRAD PRASHANT KIRAD (Options acche se padhna) VERY SHORT QUESTIONS (1 Mark) 1. The shiny finish of wall after white wash is because of. a) Calcium oxide b) Calcium hy...

ACP AARAMBH CHAPTERWISE PROBLEMS PRASHANT KIRAD PRASHANT KIRAD (Options acche se padhna) VERY SHORT QUESTIONS (1 Mark) 1. The shiny finish of wall after white wash is because of. a) Calcium oxide b) Calcium hydroxide c) Calcium Carbonate d) Calcium phosphate 2. Electrolysis of water is decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is a) 1:1 b) 2:1 c) 4:1 d) 1:2 3. Which the following statements about the given reaction are correct: 3Fe(s) + 4H 2O (g) ➜ Fe 2O 3(s) + 4H 2(g) i) Iron metal is getting oxidized ii) Water is getting reduced iii) Water is acting as reducing agent iv) Water is acting as oxidizing agent a) (i), (ii) and (iii) b) (iii) and (iv) c) (i), (ii) and (iv) d) (ii) and (iv) 4. In order to prevent the spoilage of potato chips, they are packed in plastic bags containing the gas a) Cl 2 b) O 2 c) N 2 d) H 2 5. The process of respiration is - a) an oxidation reaction which is endo thermic b) a reduction reaction which is exothermic c) a combination reaction which is endo thermic d) an oxidation reaction which is exothermic 6. Burning of Methane is an example of I. Exothermic reaction JOSH METER? PRASHANT KIRAD II. Combustion reaction III. Decomposition reaction a. I only b. II only c. I and II d. I and III 7. A solution of substance X is used for white washing. The substance X is a. Calcium oxide b. Calcium hydroxide c. Calcium carbonate d. Calcium chloride 8. When iron nails are dipped into Copper Sulphate solution. The colour of Copper Sulphate solution changes from a. Green to blue b. Blue to green c. Green to colourless d. Blue to colourless 9. The given Chemical reaction is an example of Zn + CuSO4 ➜ ZnSO 4+ Cu a. Combination reaction b. Displacement reactions c. Decomposition reaction d. Double displacement reaction 10. The balanced equation for the given chemical reaction is Hydrogen + Chlorine ➜ Hydrogen Chloride a. H 2 + Cl 2➜ 2HCl b. H + Cl ➜ HCl c. H2 + Cl 2➜ HCl d. none of the above 11. Give an example of double displacement reaction? (CBSE 2010, 2011) 12. Name the reducing agent in given chemical reaction 3 MnO2 + 4Al ➜ 3 Mn + 2Al 2O 3 (CBSE-2016) Q.13 Name the brown coloured gas evolved when lead nitrate crystal are heated in dry test-tube. Q. 14 Give reasons a) Silver chloride is stored in dark coloured bottles. b) Copper vessel loses shine when exposed to air c) Iron displaces copper from copper sulphate solution. PRASHANT KIRAD 15.Identify the following reactions as a) combination b) decomposition c) displacement reactions d) double displacement reaction. i) ZnCO3 (s) ➜ ZnO(s) + CO2(g) ii) Pb(s) + CuCl 2(aq) ➜ PbCl (aq) + Cu(s) iii) H2 (g) + Cl 2 (g) ➜ 2HCl iv) CaCO3(s) ➜ CaO (s) + CO2(g) v) NaCl(aq) + AgNO3 (a) ➜ AgCl + NaNO3 vi) 3H2(g) + N2(g) ➜2NH3(g) vii) Fe2O 3 + Al ➜ Al 2O3+2Fe 16. What changes do you observe in iron nails and colour of copper sulphate solution, if iron nails are dipped in CuSO4 , solution for Sometime? 17. Identify the chemical change: Melting of ice or conversion of milk into curd. 18. Why is respiration considered an exothermic reaction? 19. Why do copper vessel lose shine when exposed to air? 20. Potato chips manufacturers fill the packet of chips with nitrogen gas. Why? 21. Why we store silver chloride in dark coloured bottles in labs? 22. Write a chemical equation of double displacement reaction. 23. N + 3H ➜ 2NH name the type of reaction. 2 2 3 24. What happens when milk is left open at room temperature during summers ? 25. What happens when quick lime is added to water? PRASHANT KIRAD Practical Based MCQs: 1. When aqueous solution of sodium sulphate and barium chloride are mixed together, we observe a) red precipitate b) white precipitate c) yellow precipitate d) colourless solution 2. The colour of ferrous sulphate crystal is a) yellow b) light green c) red d) brown 3. A student took solid quick lime in a china dish and added a small amount of water to it. He would hear a) pop sound b) a crackling sound c) hissing sound d) no sound at all 4. When an iron nail is placed in copper sulphate solution the observation are as follow a) The solution turns light green b) A brown deposit is formed on the nail c) Both ‘a’ and ‘b’ d) None of the above (yaha Marks katate h) Assertion and Reason type of Questions In the following questions a statement of Assertion is followed by a statement of Reason. Mark the correct choice as two statements are given one labeled Assertion (A) and the other labeled Reason (R). Select the correct answer to these questions from the cods (a), (b), (c) and (d) as given below: (a) Both A and R are true, and R is correct explanation of the assertion. (b) Both A and R true, but R is not the correct explanation of the assertion. (c) A is true, but R is false. (d) A is false, but R is true. PRASHANT KIRAD 1. Assertion (R): Chemical reaction changes the physical and chemical state of substance. Reason (R): When electric current is passed through water (liquid), it decomposes to produce hydrogen and oxygen gases. 2. Assertion (R): In a balanced chemical equation, total mass of the each element towards reactant side is equal to the total mass of the same element towards product side. Reason (R): Mass can neither be created nor destroyed during a chemical change. 3. Assertion (R): When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide. Reason (R): The decomposition reaction takes place on application of heat, therefore its an endothermic reaction. 4. Assertion (R): Chips manufactures usually lush bags of chips with gas such as nitrogen to prevent the chips from getting oxidized. Reason (R): This increases the taste of the chips and helps in their digestion. 5. Assertion (R): Rusting of iron metal is the most common form of corrosion. Reason (R): The effect of rusting of iron can be reversed if they are left open in sunlight. (ho jaayenge aaram se) SHORT ANSWER TYPE QUESTIONS (2 and 3 Marks) 1. Define combination reaction. Give two examples of combination reaction which is exothermic in nature. 2. What is decomposition reaction? Explain with the help of an example. 3. Name and state the law which is kept in mind when we balance a chemical equation. 4. Give one example of each : (a) Chemical reaction showing evolution of gas. (b) Change in colour of a substance during a chemical reaction. (c) Chemical reaction showing change in temp. 5. What is rancidity? Write two ways by which it can be prevented. 6. What are two conditions which promote corrosion? PRASHANT KIRAD 7. A small amount of Ferrous sulphate is heated in hard glass tube. (a) Write the chemical equation. (b) What type of reaction is taking place or Name the type of reaction. 8. What happens when Zn strip is dipped in CuSO4 solution ? Give equation and identify the type of reaction. 9. What is redox reaction ? Write down a chemical reaction representing it. 10. In electrolysis of water : (a) Name the gas collected at cathode and anode respectively. (b) Why is volume of one gas collected at one electrode is double of another? (c) Why is it necessary to add few drops of dil. H 2 SO4 to water before electrolysis? 11. In the reaction CuO (s) + H2 (g) ➜ Cu(s) + H 2 0 (g) (a) Name the oxidized substance. (b) Name the reduced substance. (c) Name the oxidizing agent. 12. Give reasons : (a) White Silver chloride turns grey in sunlight. (b) Brown coloured copper powder on heating in air turns into black coloured substance. 13. Compound 'X' decomposes to form compound 'Y' and CO2 gas. Compound Y is used in manufacturing of cement. (a) Name the compounds 'X' and 'Y'. (b) Write the Chemical equation for this reaction. 14. A metal salt MX when exposed to light spits up to form metal M and gas X 2.. Metal M is used to make ornaments whereas gas X 2 is used in making bleaching powder. The salt MX is used in black & white photography (a) Identify the metal M and gas X 2. (b) Identify MX. (c) Write down the chemical reaction when salt MX is exposed to sunlight. 15. A metal strip X is dipped in blue coloured salt solution YSO4. After some time a layer of metal 'Y’ is formed on metal strip X. Metals X is used in galvanization whereas metal Y is used for making electric wires. (a) What could be metal 'X’ and ‘Y’? (b) Name the metal salt YSO 4 PRASHANT KIRAD (c) What type of chemical reaction takes place between X and YSO , 4 Write the balanced chemical equation. 16. When potassium Iodide solution is added to a solution of lead nitrate in test tube, a precipitate is formed. (a) State the colour of precipitate (b) Name the compound which is precipitated (c) Write balanced equation for chemical reaction. (CBSE-2015 Comptt) 17. Decomposition reactions require energy either in the form of heat or light a electricity for breaking down of reactions. Write one equation for each type of decomposition reaction where heat, light or electricity is used as form of energy 18. 2 gm of silver chloride is taken in china dish, and china dish is placed in sunlight for sometime. What will be your observation. Write the balanced chemical equation for above reaction and identify the type of reaction. (CBSE- 2019) 19. Identify the type of reactions taking place in each of following cases and write the balanced chemical equation for the reactions. a) Zn reacts with silver nitrate to produce zinc nitrate and silver. b) Potassium iodide reacts with lead nitrate to produce potassium nitrate and lead iodide (CBSE-2019) (pahle points socho firr likho) LONG ANSWER TYPE QUESTIONS (5 Marks) 1. White wash was being done at Mukesh's house. Mukesh saw that the painter added quick lime to drum having water. Mukesh touched outer surface of drum, it is unbelievably hot. (a) Write the chemical equation for above reaction. (b)What type of reaction is it? (c) This reaction is exothermic or endothermic. Justify your answer. 2. Write down the balanced chemical equation for the following : (a) Silver chloride is decomposed in presence of sunlight to give silver and chlorine gas. [b) Calcium oxide reacts with water to give lime water. (c) Sodium hydroxide reacts with hydrochloric acid to give sodium chloride and water. (d) Dil hydrochloric acid is added to copper oxide to give green coloured copper chloride and water. PRASHANT KIRAD (e) Solution of barium chloride and sodium sulphate in water reacts to give insoluble Barium sulphate and solution of Sodium chloride. (read paragraph first) Case Study/Source Based Question 1. In most pollution control applications, lime is used as calcium hydroxide. To manufacture calcium hydroxide, limestone must be converted to calcium oxide and then hydrated to form calcium hydroxide. The following is a brief chemical reaction of this process: Limestone + Heat ➜ Calcium oxide + Carbon dioxide However, calcium oxide is unstable in the presence of moisture and carbon dioxide. A more stable form of lime is calcium hydroxide. Calcium oxide + Water ➜ Calcium hydroxide + Heat The process of adding water to calcium oxide to produce calcium hydroxide is referred to as hydration process or lime slaking. The hydration of Calcium oxide; commercially referred to as quick lime, is an exothermic process releasing a great quantity of heat. The hydration takes place quickly, releasing a lot of heat energy. This heat will boil of the water and generate steam, which makes the particles burst, exposing the inner surfaces to water for further slaking. This process will continue until hydration is complete. (i) Lime is used as calcium hydroxide. The formula of lime is calcium hydroxide that absorb CO2 from air and become white, the compound formed is (a) CaO (b) CaCO 3 (c) CaCo 3 (d) CaO.2H 2O (ii) The chemical reaction of the given word equation: (a) 2CaO + Heat ➜ 2Ca + O 2 (b) CaCO3 + Heat ➜ CaO + CO 2 (c) Ca(OH)2 + Heat ➜ CaO + H 2 O (d) 2CaCO3 + Heat ➜ 2CaO + CO 2 iii) The stable form of lime is (a) Calcium hydroxide (b) Calcium oxide (c) Calcium carbonate (d) Calcium oxide. Dehydrate PRASHANT KIRAD (iv) The hydration of Calcium oxide is an (a) Exothermic reaction (b) Endothermic reaction (c) Combination and exothermic reaction (d) Decomposition and exothermic reaction (v) In a beaker take small amount of calcium oxide. When water is added to it. The temperature of the breaker will increase because: (a) A suspension of calcium hydroxide is formed (b) The beaker will be hot when touched (c) Clear solution appears when suspension of calcium hydroxide settles down to the bottom of the beaker. (d) All of the above Kitne Questions kar paaye? SOLUTIONS PRASHANT KIRAD SOLUTIONS VERY SHORT ANSWER TYPE QUESTIONS: 1.c) Calcium Carbonate 2.b) 2:1 3.c) (i),(ii) and (iv) 4.c) N2 5.d) an oxidation reaction which is exothermic 6.c) I and II 7.a) Calcium Oxide 8.b) Blue to green 9. b) Displacement Reaction 10.a) H2 + Cl 2➜2HCl 11.Na 2 So 4(aq) + BaCl 2(aq) ➜BaSo4(s) + 2NaCl 12.The reducing agent in the given reaction 3MnO₂ + 4AL → 3Mn + 2AL₂O₃ is Almunium (Al) 13.When lead nitrate crystals [Pb(NO3 ) 2 ] are heated in a dry test tube, the evolution of brown coloured nitrogen dioxide and oxygen gas takes place. 2Pb(NO3)2 (s) → 2PbO(s) + 4NO 2↑(g)+ O2 ↑(g) 14. a)Compounds Like Silver Chloride are light sensitive. And they may react to light very fast and lose its properties. That's why they are to be stored in dark bottles to prevent the entry of Light PRASHANT KIRAD SOLUTIONS VERY SHORT ANSWER TYPE QUESTIONS: 14.b)When copper vessels are exposed to air, it develops a green coating on their surface. Copper corrodes by oxidation in which it reacts with oxygen to form copper oxide, which further reacts with carbon dioxide and forms copper carbonate, which is the green colour that forms on the surface of copper which is known as verdigris. Thus copper loses its lustre. c)Iron displaces copper from copper sulphate solution but copper cannot displace iron from iron sulphate solution because copper is less reactive than iron. In such type of reaction the more reactive element displaced the less reactive element. It's an example of displacement reaction. Also the color Cooper sulphate solution is of blue color and iron sulphate of green color. 15)The Following Reactions Are: i) ZnCO₃ (s) → ZnO(s) + CO₂(g) - This is a decomposition reaction. H ii) Pb(s) + CuCl₂ (aq) → PbCl₂ (aq) + Cu(s) - This is a displacement reaction. iii) H₂(g) + Cl₂(g) → 2HCl - This is a combination reaction. iv) CaCO₃(s) → CaO (s) + CO₂(g) - This is also a decomposition reaction. v) NaCl(aq) + AgNO₃ (aq) → AgCl(s) + NaNO₃(aq) - This is a double displacement reaction. vi) 3H₂(g) + N₂(g) → 2NH₃(g) - This is a combination reaction. vii) FeO + Al → Al₂O₃ + 2Fe - This is a displacement reaction. PRASHANT KIRAD SOLUTIONS VERY SHORT ANSWER TYPE QUESTIONS: 16. Iron nails gets covered with a red-brown coating of copper metal. The blue colour of copper sulphate solution fades gradually because of the formation of iron sulphate. Reaction is as follows: Fe + CuSO4(aq) → FeSO4(aq) + Cu 17. Melting of ice is a physical change. Conversion of milk to curd is a chemical change as the reaction is irreversible and the curd formed once cannot be converted to milk again. 18. Respiration is considered as a exothermic reaction because heat is produced during the process of respiration, The carbon dioxide in the food breaks down to create glucose during the process. This glucose reacts with oxygen in our cells, releasing a large amount of energy. Hl 19. When copper vessels are exposed to air, it develops a green coating on their surface. Copper corrodes by oxidation in which it reacts with oxygen to form copper oxide, which further reacts with carbon dioxide and forms copper carbonate, which is the green colour that forms on the surface of copper which is known as verdigris. Thus copper loses its lustre. 20.The potato chips manufacturer uses nitrogen gas to flush the chips bags to prevent the chips from getting oxidized in presence of oxygen from the atmosphere. When fats and oils are oxidized they become rancid and their smell and taste change. 21. Compounds Like Silver Chloride are light sensitive. And they may react to light very fast and lose its properties. That's why they are to be stored in dark bottles to prevent the entry of Light PRASHANT KIRAD SOLUTIONS VERY SHORT ANSWER TYPE QUESTIONS: 22. The example of double displacement reaction is NaCl(aq) + AgNO₃ (aq) → AgCl(s) + NaNO₃(aq) 23. N2+ 3H2 ➜ 2NH3 is a combination reaction 24. When milk is left at room temperature during the summer, it undergoes an oxidation reaction and microbe development, causing it to become sour. It also begins to break, which can be seen on the top of the vessel. 25. When water is added to quicklime, calcium hydroxide is obtained with the evolution of heat. There is a rise in temperature. CaO(s) + H2 O (l) ➜ Ca(OH)2 + Heat ↑ 26. 1. b) white precipitate Hl 2. b) light green 3. c) hissing sound 4. a) The solution turns light green 27. 1. (a) Both A and R are true, and R is correct explanation of the assertion. 2. (a) Both A and R are true, and R is correct explanation of the assertion. 3. (a) Both A and R are true, and R is correct explanation of the assertion. 4. (c) A is true, but R is false. 5. (b) Both A and R are true, but R is not the correct explanation of the assertion. PRASHANT KIRAD SOLUTIONS SHORT ANSWER TYPE QUESTION: 1. When two or more substances (elements or compounds) combine to form a single product, the reactions are called combination reactions. This can be represented by the general equation: A+B→AB The Two Examples of Combination Reactions Which Are Exothermic In Nature Are - Combustion of magnesium (Mg) in air, where magnesium (Mg) combines with oxygen (O2) to form magnesium oxide(MgO) ,along with the liberation of heat. Thus it is considered an Exothermic Reaction 2Mg(s)+O2 (g)→ 2MgO(s) + Heat When quicklime (Cao) reacts with water (H 2O), Calcium hydroxide (Ca(OH)2) is formed along with the liberation of heat. Thus it is considered an Exothermic reaction. CaO(s)+H2 O(l)→Ca(OH)2 (aq)+Heat Hl 2. Those reaction in which a compound splits up into two or more than two simpler substance are known as decomposition reaction. This can be represented by the general equation: AB → A + B. Example Of Decomposition Reactions is Calcium carbonate (CaCO 3) decomposes into calcium oxide (Cao) and carbon dioxide ( Co2 )when heated Heat CaCO3(s) → CaO(s)+CO2(g) 3. It is the law of conservation of mass which states that mass can neither be created nor destroyed. So both the sides of the chemical reactions have to be balanced to ensure that this law is followed. PRASHANT KIRAD SOLUTIONS SHORT ANSWER TYPE QUESTION: 4. a) The chemical reaction between zinc(Zn) and dilute sulphuric acid(H2SO4) in this reaction Zinc Sulphate(ZnSO4 ) is formed and Hydrogen gas is evolved (H2) Zn(s)+H2SO4(aq)→ZnSO4(aq)+H2↑(aq) b) The reaction between lead nitrate(Pb(NO3)2 ) solution and potassium iodide (2KI) solution.Before reaction the solution is colourless and after reaction the yellow colour lead iodide (PbI2 ) is formed And Also Potassium Nitrate(2KNO 3) is formed. Pb(NO3) 2 (aq)+2KI→Pbl2 (s)+2KNO3(aq) c) When dilute sulphuric acid (H2SO4)is added to zinc (Zn)granules, hydrogen (H2)gas is evolved and zinc sulphate (ZnSO4) is formed along with the release of heat. Zn(s)+H 2SO 4(aq)→ZnSO 4+H2↑(g)+Heat↑ 5. The oxidation of oils or fats in a food resulting into bad smell and bad taste is called rancidity. It can be prevented by- i adding anti- oxidants. ii flushing with nitrogen gas. 6. The circumstances that leads to corrosion are as follows: i. Corrosion occurs when there is an abundance of oxygen. ii. Corrosion is also caused by the presence of contaminants such as Carbon dioxide and Chloride. 7. (a) The Chemical Equation is 2FeSO4➜ Fe 2O 3+ SO 2 + SO 3 (b) Decomposition reaction is taking place. Since heat is used it is also known as thermal decomposition reaction. 8. Zinc displaces copper from copper sulphate and generates zinc sulphate solution when added to CuSO4 solution because zinc is a more reactive metal that displaces less reactive metal from its solution for this reason displacement reaction occurs. A color change from blue to colorless indicates this. Zn(s)+CuSO4(aq)➜ ZnSO (aq) + Cu(s) 4 PRASHANT KIRAD SOLUTIONS SHORT ANSWER TYPE QUESTION: 9. Redox reactions are reactions in which both the oxidation and reduction processes take place simultaneously. Example of redox reaction:An example of a redox reaction is:In the above reaction, hydrogen is oxidized to water 2H2(g) + O2(g) ➜ 2H2 O 10.(a) a.The gas formed at anode and cathode: The process of using electricity to split water into hydrogen and oxygen is known as electrolysis. 2H₂O(l) ➜ 2H₂(g) + O₂(g) Water Hl Hydrogen Oxygen Hydrogen gas released at the cathode Oxygen gas is released at anode (b).The volume of gas collected: Two moles of water undergo electrolysis and produce two moles hydrogen and one mole of oxygen gas. Because the water molecule contains two hydrogens and one oxygen in its molecular formula. (c). If dilute H₂SO₄ is not added: Water is a bad conductor of electricity. So, when a direct current is passed through the water it won't conduct. Therefore to make the electrolysis happen, a few drops of sulphuric acidH₂SO₄ to the water in the electrolysis of water. PRASHANT KIRAD SOLUTIONS SHORT ANSWER TYPE QUESTION: 11.a)H₂ is the substance oxidised. b) CuO is the substance reduced. c) CuO is the oxidising agent. 12. (a) White coloured silver chloride undergoes decomposition in the presence of sunlight and forms silver (grey in colour) and chlorine. (b) Brown coloured copper powder on heating in air gets oxidised to copper oxide which is black in colour 13. Calcium carbonate (limestone) decomposes on heating to give calcium oxide and carbon dioxide. (a) X is calcium carbonate and Y is Calcium Oxide Hl (b) CaCO₃(s) → CaO(s) + CO₂(g) 14. a) Metal M is Silver (Ag) and Gas X2 is Chlorine gas (Cl₂) (b) The metal salt MX is Silver chloride (AgCl). (c) The chemical reaction when silver chloride (AgCl) is exposed to sunlight is: 2AgCl(s) → 2Ag(s) + Cl₂(g) In this reaction, silver chloride decomposes into silver metal (Ag) and chlorine gas (Cl₂) due to the energy from sunlight breaking the chemical bonds in the silver chloride. PRASHANT KIRAD SOLUTIONS SHORT ANSWER TYPE QUESTION: 15. (a) Metal X is likely zinc (Zn) because zinc is commonly used in galvanization, which is the process of applying a protective zinc coating to iron or steel to prevent rusting. Metal Y is likely copper (Cu) because copper is commonly used for making electric wires due to its excellent electrical conductivity. (b) The metal salt YSO₄ could be copper sulfate (CuSO₄). Copper sulfate is often used in industrial applications and is known for its blue color when dissolved in water. (c)The type of chemical reaction that takes place between metal X (likely zinc) and the salt solution YSO₄ (likely copper sulfate) is a single displacement reaction, also known as a displacement reaction or a substitution reaction. In this reaction, the more reactive metal (zinc) displaces the less reactive metal (copper) from its salt solution. The balanced chemical equation for this reaction is: Hl Zn(s) + CuSO₄(aq) → ZnSO₄(aq) + Cu(s) In words, this equation reads as: Zinc (s) + Copper sulfate (aq) → Zinc sulfate (aq) + Copper (s) In this reaction, zinc replaces copper in the copper sulfate solution, leading to the formation of zinc sulfate and copper metal. 16.(a) The precipitate formed when potassium iodide solution is added to a solution of lead nitrate is yellow in color. (b) The compound that is precipitated is lead iodide, which is insoluble in water and forms a yellow precipitate. (c) The balanced chemical equation for this reaction is: Pb(NO₃)₂(aq) + 2KI(aq) → PbI₂(s) + 2KNO₃(aq) In words, this equation reads as: Lead nitrate (aq) + Potassium iodide (aq) → Lead iodide (s) + Potassium nitrate (aq) PRASHANT KIRAD SOLUTIONS SHORT ANSWER TYPE QUESTION: 17. The following decomposition reaction are Thermal Decomposition (heat): Calcium carbonate (CaCO₃) decomposes upon heating to form calcium oxide (CaO) and carbon dioxide (CO₂) Heat CaCO₃(s) → CaO(s) + CO₂(g) Photodecomposition (light): Silver chloride (AgCl) decomposes upon exposure to light to form silver (Ag) and chlorine (Cl₂) Light 2AgCl(s) → 2Ag(s) + Cl₂(g) Electrolytic Decomposition (electricity): Water (H₂O) can be electrolyzed using electricity to form hydrogen gas (H₂) and Hl oxygen gas (O₂) Electricity 2H₂O(l) → 2H₂(g) + O₂(g) 18.Observation: The silver chloride (AgCl) will gradually turn gray as it decomposes into silver (Ag) and chlorine gas (Cl₂) upon exposure to sunlight. Balanced chemical equation: Type of reaction: This is a photodecomposition reaction, where the compound decomposes upon exposure to light.(a) The reaction between zinc (Zn) and silver nitrate (AgNO₃) is a single displacement reaction. Zinc replaces silver in the compound to form zinc nitrate (Zn(NO₃)₂) and silver (Ag). The balanced chemical equation is:Zn + 2AgNO₃ → Zn(NO₃)₂ + 2Ag (b) The reaction between potassium iodide (KI) and lead nitrate (Pb(NO₃)₂) is a double displacement reaction. Potassium iodide and lead nitrate exchange ions to form potassium nitrate (KNO₃) and lead iodide (PbI₂). The balanced chemical equation is: 2KI + Pb(NO₃)₂ → 2KNO₃ + PbI₂ 2AgCl(s) + light → 2Ag(s) + Cl₂(g), PRASHANT KIRAD SOLUTIONS SHORT ANSWER TYPE QUESTION: 19. (a) The reaction between zinc (Zn) and silver nitrate (AgNO₃) is a displacement reaction. Zinc replaces silver in the compound to form zinc nitrate (Zn(NO₃)₂) and silver (Ag). The balanced chemical equation is: Zn + 2AgNO₃ → Zn(NO₃)₂ + 2Ag (b) The reaction between potassium iodide (KI) and lead nitrate (Pb(NO₃)₂) is a double displacement reaction. Potassium iodide and lead nitrate exchange ions to form potassium nitrate (KNO₃) and lead iodide (PbI₂). The balanced chemical equation is: 2KI + Pb(NO₃)₂ → 2KNO₃ + PbI₂ Hl PRASHANT KIRAD SOLUTIONS LONG ANSWER TYPE QUESTION: 1. (a) The chemical equation for the reaction when quicklime (calcium oxide, CaO) is added to water (H₂O) to form slaked lime (calcium hydroxide, Ca(OH)₂) is: CaO + H₂O → Ca(OH)₂ (b) This reaction is a combination reaction, also known as a synthesis reaction, where two or more substances combine to form a single product. (c) The reaction is highly exothermic. This is because when water is added to quicklime, it undergoes a strong exothermic reaction, releasing a large amount of heat. This heat causes the drum to become very hot, as observed by Mukesh when he touched the outer surface of the drum. 2.(a) Silver chloride is decomposed in the presence of sunlight to give silver and chlorine gas: Hl 2AgCl(s) + light → 2Ag(s) + Cl₂(g) (b) Calcium oxide reacts with water to give lime water: CaO(s) + H₂O(l) → Ca(OH)₂(aq) (c) Sodium hydroxide reacts with hydrochloric acid to give sodium chloride and water: NaOH(aq) + HCl(aq) → NaCl(aq) + H₂O(l) (d) Dilute hydrochloric acid is added to copper oxide to give green colored copper chloride and water: CuO(s) + 2HCl(aq) → CuCl₂(aq) + H₂O(l) (e) This equation represents the reaction between barium chloride and sodium sulfate to form insoluble barium sulfate and soluble sodium chloride. BaCl₂(aq) + Na₂SO₄(aq) → BaSO₄(s) + 2NaCl(aq) PRASHANT KIRAD SOLUTIONS CASE STUDY / SOURCE BASED TYPE QUESTION: 1.(i) (b) CaCO₃ (ii) (d) 2CaCO₃ + Heat → 2CaO + 2CO₂ (iii) (a) Calcium hydroxide (iv) (a) Exothermic reaction (v) (d) All of the above Hl