Posts

Chapter 2 acids bases and salts notes

  Class 10 Science Chapter 2: Acids, Bases, and Salts – Short Notes 1. Acids: Substances that release hydrogen ions ( H + )  in water. Examples : Hydrochloric acid (HCl), Sulfuric acid (H 2 ​ SO 4 ). Properties : Sour taste. Turns blue litmus red. Reacts with metals to release hydrogen gas. 2. Bases: Substances that release hydroxide ions ( O H − )  in water. Examples : Sodium hydroxide (NaOH), Calcium hydroxide [Ca(OH) 2 ]. Properties : Bitter taste. Soapy touch. Turns red litmus blue. Reacts with acids to form salt and water (neutralization). 3. Indicators : Substances used to determine whether a solution is acidic or basic. Examples : Litmus paper : Red in acid, blue in base. Phenolphthalein : Colorless in acid, pink in base. Methyl orange : Red in acid, yellow in base. 4. pH Scale : A scale to measure the acidity or basicity of a solution. Ranges from 0 to 14: pH < 7 : Acidic. pH = 7 : Neutral. pH > 7 : Basic. pH of common substances : Stomach acid: 1.5 Pure wat...
Post a Comment
Read more

Chemical Reactions and Equations Class 10 Notes

  Class 10 Science Chapter 1: Chemical Reactions and Equations – Short Notes 1. Chemical Reactions: A chemical reaction occurs when one or more substances react to form new substances with different properties. Reactants : Substances that undergo the reaction. Products : New substances formed after the reaction. 2. Characteristics of Chemical Reactions: Chemical reactions involve: Change in state : Solid to liquid or gas (e.g., ice melting). Change in color : (e.g., rusting of iron). Evolution of gas : (e.g., hydrogen gas released in reaction with metals). Change in temperature : Exothermic (releases heat) or Endothermic (absorbs heat). Formation of precipitate : Insoluble solid is formed (e.g., reaction between barium chloride and sulfuric acid). 3. Chemical Equations: A chemical equation represents a chemical reaction using symbols and formulas. Word equation : Represents reaction using words (e.g., Magnesium + Oxygen → Magnesium oxide). Balanced chemical equation : The number ...
Post a Comment
Read more