explain in english with proper visual---Here is the extracted content from the image: **Other Relevant Text:** "Facts are not science — as the dictionary is not literature." Martin H. Fischer **Chapter Information:** CHAPTER 1 Chemical Reactions and Equations **Chart/Diagram Description:** * **Type:** Diagram of a laboratory apparatus and a QR code. * **Main Elements:** * **Laboratory Apparatus:** A conical flask (Erlenmeyer flask) is depicted on the left side of the page. It contains a light-colored granular or powdered substance at the bottom. The flask is sealed with a stopper, from which a narrow tube extends upwards. * **QR Code:** A square QR code is present on the right side of the page. Below the QR code, the text "1064CH01" is printed. **Question Stem (Implicit Introduction to Topic):** Consider the following situations of daily life and think what happens when – * milk is left at room temperature during summers. * an iron tawa/pan/nail is left exposed to humid atmosphere. * grapes get fermented. * food is cooked. * food gets digested in our body. * we respire. **Other Relevant Text (Continuation):** In all the above situations, the nature and the identity of the initial substance have somewhat changed. We have already learnt about physical and chemical changes of matter in our previous classes. Whenever a chemical change occurs, we can say that a chemical reaction has taken place. You may perhaps be wondering as to what is actually meant by a

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Chemical changes are transformations that occur all around us in daily life. When milk is left at room temperature during summer, it becomes sour due to bacterial action. When iron objects are exposed to humid air, they develop rust, changing from metallic iron to iron oxide. Grapes undergo fermentation to produce wine, where sugars are converted to alcohol. In all these examples, the original substances are transformed into entirely new substances with different properties. This is what we call a chemical reaction - a process where the nature and identity of the initial substances change completely. Understanding the difference between physical and chemical changes is fundamental in chemistry. Physical changes only affect the form or state of matter without creating new substances. For example, when ice melts to become water, or when paper is torn into pieces, the molecular composition remains the same. These changes are usually reversible. In contrast, chemical changes involve the formation of entirely new substances with different molecular structures and properties. When paper burns to form ash, or when a raw egg is cooked, the original substances are transformed into completely different materials. Chemical changes are typically irreversible and involve breaking and forming of chemical bonds. A chemical reaction is a fundamental process in chemistry where one or more substances, called reactants, are converted into different substances called products. During this transformation, chemical bonds are broken and new bonds are formed, resulting in substances with entirely new chemical properties. Let's examine the formation of water as an example. When hydrogen gas combines with oxygen gas, they react to form water molecules. In this reaction, hydrogen and oxygen are the reactants, while water is the product. The molecular structure changes completely as hydrogen and oxygen atoms form new bonds to create water molecules. Chemical reactions can be observed in laboratory settings using various apparatus, and they often involve energy changes such as the release or absorption of heat. Chemical equations are the symbolic language of chemistry, providing a concise way to represent chemical reactions using chemical formulas and symbols. They serve as a universal scientific language that allows chemists worldwide to communicate reaction information clearly and precisely. A chemical equation consists of reactants on the left side and products on the right side, connected by an arrow that indicates the direction of the reaction. Let's see how we transform a word equation into a proper chemical equation. We start with a word equation like 'Hydrogen plus Oxygen yields Water.' This is then converted to chemical formulas: H₂ plus O₂ yields H₂O. However, this equation is not balanced, meaning the number of atoms on each side is not equal. The final step is balancing the equation to show the correct proportions: 2H₂ plus O₂ yields 2H₂O. Chemical equations are essential for understanding reaction stoichiometry and performing quantitative calculations in chemistry. Balancing chemical equations is based on the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. This means the total number of atoms of each element must be the same on both sides of the equation. Let's learn how to balance equations step by step. We start with an unbalanced equation: H₂ plus O₂ yields H₂O. First, we count the atoms on each side. On the reactant side, we have 2 hydrogen atoms and 2 oxygen atoms. On the product side, we have 2 hydrogen atoms but only 1 oxygen atom. The oxygen is not balanced. To balance the oxygen, we add a coefficient of 2 in front of water, giving us 2H₂O. But now we have 4 hydrogen atoms on the product side, so we need to add a coefficient of 2 in front of H₂ on the reactant side. Our final balanced equation is: 2H₂ plus O₂ yields 2H₂O. Now we have 4 hydrogen atoms and 2 oxygen atoms on both sides. The equation is balanced, and the law of conservation of mass is satisfied.