Chemical Reactions & Equation Class 10 science Notes

Chemical reaction:
-> the processes in which one or more substances undergo chemical changes to form different substances with different properties.
Examples:-
- rusting of iron
- burning of wood
- formation of curds
- respiration etc.
Class 10 Handwrritten Notes Chemical Reactions and Equation With helps To better Score in examination.
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Transcript

1. HomeClass 10 class 10 science handwritten notes pdf by edumantra by Vidyapeethclasses • March 08, 2023 0 Chemical reaction: -> the processes in which one or more substances undergo chemical changes to form different substances with different properties. Examples:- - rusting of iron - burning of wood - formation of curds - respiration etc. The following observations help to determine if a chemical reaction has occurred: 1) Change of state JEE Free JEE Exam Preparations Neet Free Neet classes and proper notes Explore Now  HOME STUDY MATERIAL  
2. • Change in state is a type of chemical reaction in which a substance undergoes a physical change from one state to another, without any change in its chemical composition. In Class 10, students learn about the changes in state that occur in different types of chemical reactions, such as: • Melting and freezing: When a solid substance is heated, it melts and becomes a liquid, and when a liquid is cooled, it freezes and becomes a solid. The change in temperature causes the particles of the substance to gain or lose energy, which leads to the change in state. • Evaporation and condensation: When a liquid substance is heated, it evaporates and becomes a gas, and when a gas is cooled, it condenses and becomes a liquid. The change in temperature and pressure causes the particles of the substance to gain or lose energy and move farther apart or closer together, which leads to the change in state. • Sublimation and deposition: When a solid substance is heated, it undergoes sublimation and becomes a gas, and when a gas is cooled, it undergoes deposition and becomes a solid. Sublimation and deposition occur in certain substances that have weak intermolecular forces and can undergo a change in state directly from solid to gas or gas to solid. Popular Posts class 10 science handwritten notes pdf by edumantra March 08, 2023 Categories Class 10 (4) Find Us About Us:- Our Site Provide Board And Jee Level Content Provides In This Website.In This Site Handwrritten Note And Many More Study Materials Provide For You , Then Its Help More Marks In Any Exam. Head Office : Biharsharif(BIHAR). Branch Office : Biharsharif(BIHAR). Phone : +918383383779, +917832640176 Email : vidyapeethclasses23@gmail.com Youtube : youtube.com/@vidyapeethclasses
3. • In chemical equations, the change in state is represented using different symbols, such as (s) for solid, (l) for liquid, (g) for gas, and (aq) for aqueous solution. For example, the chemical equation for the reaction between solid sodium hydroxide and hydrochloric acid in aqueous solution is: NaOH(s) + HCl(aq) → NaCl(aq) + H2O(l) • In this equation, the solid sodium hydroxide reacts with the aqueous hydrochloric acid to form the aqueous sodium chloride and liquid water. The change in state is indicated using the symbols (s) and (l) for solid and liquid, respectively. 2) Change of color • A change in color is a common indication of a chemical reaction. In Class 10, students learn about different types of chemical reactions that result in a change of color. Here are some examples: • In a combustion reaction, a substance reacts with oxygen to produce heat, light, and new substances. For example, when magnesium ribbon burns in air, it reacts with oxygen to form magnesium oxide. The magnesium ribbon burns with a bright white flame, indicating a chemical reaction is taking place. • In a precipitation reaction, two aqueous solutions react to form a solid that separates from the solution as a precipitate. The color of the precipitate can be different from the colors of the reactants. For example, when silver nitrate solution is added to sodium chloride solution, a white precipitate of silver chloride is formed. • In an acid and base react formed salt and water is also known as acid & base reaction.The color of the solution may change depending on the strength of the acid and base. For example, when hydrochloric acid is added to a solution of sodium March 2023 (6) Our Team Harshit Raj Yogesh Raj Pages Shorts Comments Search 
4. hydroxide, the solution turns from colorless to pink due to the formation of sodium chloride and water. • In a redox reaction, the oxidation state of one or more elements changes, and this change may be indicated by a change in color. For example, when iron (II) sulfate reacts with potassium permanganate in acidic medium, the purple color of potassium permanganate disappears, indicating that it has been reduced, and the solution turns brown due to the formation of iron (III) ions. 3) Evolution of gas • The evolution of gas is a common phenomenon observed in many chemical reactions. In Class 10, students learn that when a gas is evolved in a chemical reaction, it indicates that a new substance is being formed. Here are some examples of chemical reactions where gas evolution occurs: • In the reaction between sodium bicarbonate (baking soda) and acetic acid (vinegar), carbon dioxide gas is evolved. • example:- NaHCO3 + CH3COOH → NaCH3COO + H2O + CO2 • When hydrochloric acid reacts with calcium carbonate, carbon dioxide gas is evolved. • The reaction between zinc metal and hydrochloric acid also produces hydrogen gas. The chemical equation for this reaction is:
5. Zn + 2HCl → ZnCl2 + H2 • When magnesium metal reacts with hydrochloric acid, hydrogen gas is evolved. Mg + 2HCl → MgCl2 + H2 • In the reaction between sodium metal and water, hydrogen gas is evolved. 2Na + 2H2O → 2NaOH + H2 • In all of these reactions, the evolution of gas is an indication that a new substance is being formed. The study of gas evolution in chemical reactions is an essential part of chemistry and helps in understanding the nature and properties of different substances. 4)Change of temperature • Temperature is one of the factors that affect the rate of a chemical reaction. In Class 10, students learn about the effect of temperature on chemical reactions and how it is related to the kinetic energy of the particles involved in the reaction. Here are some notes on the change in temperature in chemical reactions and equations: • The rate of a chemical reaction increases with an increase in temperature. This is because an increase in temperature results in an increase in the kinetic energy of the particles involved in the reaction, which leads to more frequent and energetic collisions between the particles. • The activation energy of a chemical reaction is the minimum amount of energy required for the reactant molecules to react and form the products. An increase in
6. temperature provides the reactant molecules with more energy, making it easier for them to overcome the activation energy barrier and react. • On the other hand, a decrease in temperature decreases the kinetic energy of the particles involved in the reaction, which leads to a decrease in the rate of the reaction. • In some cases, changes in temperature can also affect the equilibrium position of a reversible reaction. An increase in temperature shifts the equilibrium position in the direction that absorbs heat, while a decrease in temperature shifts the equilibrium position in the direction that releases heat. • The change in temperature during a chemical reaction can be measured using a thermometer. The change in temperature is calculated by subtracting the initial temperature from the final temperature. • The heat of reaction is the amount of heat energy released or absorbed during a chemical reaction. The heat of reaction can be calculated using the change in temperature and the specific heat capacity of the substances involved in the reaction. • Reagent/Reactant: substances involved in a chemical reaction. • Product: substances produced in a chemical reaction. Chemical equation: - The symbolic representation of a chemical reaction is said to be a chemical equation. - This involves using the symbol of the elements or the chemical formula of the reactant and product to indicate the physical state.
7. - The necessary conditions such as temperature, pressure or any catalyst must be written on the arrow between the reactant and the products. Example: Magnesium is burned in air to form magnesium oxide can be represented as Mg O → MgO NOTE:- -> The physical state of reactant and products are mentioned to make the chemical reaction more informative. Example: Use for (g) gas, (l) liquid, (s) solid and (water). So it is good for chemical reactions and equations. Balancing Chemical Equation: - Chemical Reactions and Equations also includes average balanced equations using several methods. The steps to balance a chemical equation are: a. Write the chemical equation of unbalanced equation in notebook. b. Count the number of atoms of each element on both sides of the equation.
8. c. Add coefficients to balance the number of atoms of each element. d. Verify that the equation is balanced by counting the number of atoms of each element again. • In a redox reaction, the oxidation number of the elements involved changes. The oxidation number is the charge that an atom would have if the shared electrons were divided equally between the atoms in a compound. • In a displacement reaction, a higher reactive element displaces a lower reactive element from its compound in a reaction. • In a double displacement reaction, one ions interchange ion from one place to another place. • al reaction are temperature, concentration, surface area, and the presence of a catalyst. • Law of Conservation of Mass: - Mass cannot be created or destroyed in a chemical reaction. - The number of elements contained on the product side is therefore the same as with the initial material. H2+ O2 → H2O - In this chemical equation, the number of H atoms is 2 on the reactant side and 2 on the product side as well. The number of O atoms on the reactant side is 2, but on the product side is 1.
9. - To balance this equation, we must use hit and trial. 2H2 +O2 → 2H2O - Now the number of atoms on the reactant side is the same as on the product side. In balance then. Types of Chemical Reactions: There are several types of chemical reactions based on different factors - Based on Chemical Change: There are a total of 8 types of chemical reactions . 1) Combination Reaction - A reaction in which two or more substances combine to form a new single substance . CO2 → C+O2 Or • Combination reactions are a type of chemical reaction in which two or more substances combine to form a single new substance. In other words, the reactants in a combination reaction are simpler substances, and the product is a more complex substance. The general form of a combination reaction can be represented as: A + B → AB
10. Where A and B are the reactants, and AB is the product. Here are some examples of combination reactions: • 2H2 + O2 → 2H2O In this reaction, hydrogen gas and oxygen gas combine to form water. • Mg + O2 → MgO In this reaction, magnesium metal and oxygen gas combine to form magnesium oxide. • N2 + 3H2 → 2NH3 In this reaction, nitrogen gas and hydrogen gas combine to form ammonia. • C + O2 → CO2 In this reaction, carbon and oxygen gas combine to form carbon dioxide. • Combination reactions are often exothermic, which means they release heat energy. They can occur spontaneously or may require a source of energy to initiate the reaction. Combination reactions play an essential role in many natural and industrial processes, such as photosynthesis, combustion, and the synthesis of various chemical compounds. 2) Decomposition reaction - a reaction in which one substance decomposes to form two or more substances.
11. Nacl → Na+Cl Or • Decomposition reaction is a type of chemical reaction in which a single compound breaks down into two or more simpler substances. In this reaction, a compound is decomposed or broken down into its constituent elements or simpler compounds. This process is the opposite of a combination reaction in which two or more substances combine to form a single compound. • A decomposition reaction can be represented by a chemical equation in which the reactant compound is written on the left side of the arrow and the products are written on the right side of the arrow. The general form of a decomposition reaction is as follows: AB → A + B In this equation, AB represents the reactant compound, while A and B represent the products formed as a result of the decomposition. These are mainly two types of decomposition reactions: • Thermal decomposition: This type of decomposition occurs when a compound is heated to a high temperature, causing it to break down into simpler substances. For example, the thermal decomposition of calcium carbonate (CaCO3) results in the formation of calcium oxide (CaO) and carbon dioxide (CO2). CaCO3(s) → CaO(s) + CO2(g)
12. • Electrolytic decomposition: This type of decomposition occurs when an electric current is passed through an electrolyte solution, causing it to break down into its constituent elements or simpler compounds. For example, the electrolytic decomposition of water (H2O) results in the formation of hydrogen gas (H2) and oxygen gas (O2). 2H2O(l) → 2H2(g) + O2(g) • Decomposition reactions are important in many natural and industrial processes. They are used in the production of various chemicals, including metals, acids, and bases. They also play a crucial role in the decomposition of organic matter in nature, such as the breakdown of leaves and other plant material in soil. Decomposition reactions can be of three types - i) Thermal decomposition - When the decomposition reaction is carried out by heating. Ca+CO3 → CaO +CO2 ii) Electrolytic decomposition – When the decomposition occurs by conducting electricity. 2H2O electric current → 2H2 +O2 iii) Photolytic decomposition - When the decomposition takes place under the influence of sunlight.
13. 2AgCl+ sunlight → 2Ag (s)+Cl2 3) Displacement reaction - a chemical reaction in which an element displaces another element from a solution. Fe+ CuSO→ FeSO+Cu Or • Displacement reactions are a type of chemical reaction in which one element or group of elements is displaced or replaced by another element or group of elements. In a displacement reaction, a more reactive element replaces a less reactive element in a compound, forming a new compound. Displacement reactions can be categorized as single displacement reactions or double displacement reactions. • In Displacement reactions are a type of chemical reaction in which one element or group of elements is displaced or replaced by another element or group of elements . For example, when magnesium metal is added to copper sulfate solution, the magnesium replaces the copper in the compound, forming magnesium sulfate and copper metal: Mg + CuSO4 → MgSO4 + Cu In this reaction, the more reactive magnesium displaces the less reactive copper in the compound. • Displacement reactions are a type of chemical reaction in which one element or group of elements is displaced or replaced by another element or group of
14. elements. For example, when silver nitrate solution is mixed with sodium chloride solution, silver chloride and sodium nitrate are formed: AgNO3 + NaCl → AgCl + NaNO3 In this reaction, the silver and sodium ions exchange places, forming new compounds. • Displacement reactions are important in various fields such as metallurgy, corrosion, and biological systems. Understanding the principles of displacement reactions is essential in predicting the behavior of substances in different chemical environments. 4) Double transition reaction /Double Displacement reaction - a reaction during which two different atoms or groups of atoms are exchanged. Na2SO+BaCl2 → BaSO+ 2NaCl Or • A double displacement reaction, also known as a double replacement reaction or metathesis reaction, is a type of chemical reaction where the cations and anions of two different compounds switch places, resulting in the formation of two new compounds. the reactants are two ionic compounds in aqueous solution in double displacement reaction. The general form of a double displacement reaction can be represented by the following equation: AB + CD → AD + CB
15. where A and B are cations in the first compound, C and D are anions in the second compound, and AD and CB are the new compounds formed after the reaction. Some examples of double displacement reactions include the reaction between sodium chloride and silver nitrate to form silver chloride and sodium nitrate: NaCl (aq) + AgNO3 (aq) → AgCl (s) + NaNO3 (aq) • Another example is the reaction between barium chloride and sodium sulfate to form barium sulfate and sodium chloride: BaCl2 (aq) + Na2SO4 (aq) → BaSO4 (s) + 2NaCl (aq) • Double displacement reactions can also occur in the gas phase or in a solid state, but they are most commonly observed in aqueous solutions. The identification of double displacement reactions is important in analytical chemistry, where the reactions are often used to identify and separate different ions in a mixture. 5) Precipitation reaction - The reaction associated with the formation of a precipitate (insoluble substance) is called a precipitation reaction. Pb(NO3)2+ 2KI → 2KNO3 +PbI2 Or • Precipitation reactions are a type of double displacement reaction where an insoluble solid, called a precipitate, is formed when two aqueous solutions are mixed. In these reactions, the cations and anions of the two reactants switch places, forming
16. new compounds that have different solubilities in water. If the product formed is insoluble in water, it appears as a solid, or precipitate. • In precipitation reactions, the reactants are usually ionic compounds dissolved in water, and the products are also ionic compounds. The reaction can be represented by a chemical equation, which shows the reactants and products involved in the reaction. For example, the reaction between silver nitrate and sodium chloride can be represented by the following chemical equation: AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq) • In this reaction, silver nitrate and sodium chloride are the reactants, and silver chloride and sodium nitrate are the products. When these two solutions are mixed, a white precipitate of silver chloride is formed, which is insoluble in water. • Precipitation reactions have many practical applications, such as in the purification of water, the production of pigments and dyes, and the detection and identification of ions in a solution. Precipitation reactions can also be used to separate and purify different components of a mixture. 6) Oxygenation reaction/Oxidation reaction - A reaction in which a substance gains oxygen or loses hydrogen is called an oxidation reaction. 2Cu+ O2 Heat → 2CuO 7) Reduction reaction
17. - A reaction in which a substance gains hydrogen or loses oxygen is called a reduction reaction. C +2H2 → CH4 8) Oxidation - reduction reaction (redox reaction) - A reaction in which one reactant is oxidized and another reactant is reduced is called an oxidation-reduction reaction or a reaction reaction. In this reaction, simultaneous oxidation and reduction reactions occur. i) ZnO+ C → Zn+ CO ii) MnO2 + 4HCl → MnCl2 + 2H2O + Cl2 Exothermic Reactions - Reaction in which heat is released along with formation of products. CH4 + 2O2 → CO2 + 2H2O + Heat Endothermic Reactions - Reactions that require energy in the form of heat, light or electricity to break down the reactants are called endothermic reactions. 2Pb(NO3)2 Heat → 2PbO +NO2 +O2 Effects of oxidation in daily life:
18. You might like 1) Corrosion (जंग लगना) – When a metal is exposed to an acid layer, moisture etc. occurs which weakens the metal and thus the metal is said to corrode. - Iron rusting, silver black coating and copper green coating are examples of corrosion. Corrosion can be prevented by electroplating, electroplating or painting. 2) Rancidity - Oxidation of fats and oils when exposed to air is called rancidity. This leads to a bad smell and taste of the food. • Methods to prevent rancidity : - Adding antioxidants - Storing food in an airtight container - Replacing air with nitrogen - Refrigeration handwrritten Notes for class 10 chemical reactions and equations best of luck best study material of all examamination.