Notes of Ch 2 Acids, Bases and Salts: Class 10th Science Introduction The sour and bitter tastes of food are due to acids and bases are present in them. Acids are sour in taste and change the colour of blue litmus to red. Litmus solution is a purple dye, which is extracted from lichen. When the litmus solution is neither acidic nor basic, its colour is purple. Other natural materials like red cabbage leaves, turmeric, coloured petals of some flowers such as Hydrangea, Petunia and Geranium, which indicate the presence of acid or base in a solution. Properties of Acids They release H + ions in aqueous solution. Acids have sour taste. They turn blue litmus solution red. They give H + ions in aqueous solution. Strong Acids: HCl, H 2 SO 4 , HNO 3 Weak Acids: CH 3 COOH, Oxalic acid, Lactic acid Concentrated Acids: More amount of acid + Less amount of water Dilute Acids: More amount of water + Less amount of acid Properties of Bases They have a bitter taste. They are soapy to t
Notes of Ch 1 Chemical Reactions and Equations| Class 10th Science Introduction → Most of the substance around us undergoes various changes. Some of these changes are temporary with no new substance being formed. They are called physical changes. → In certain other changes the new substance formed in which the reactant or the parent loses its identity to form new substance called product. These changes are permanent changes as we won’t get the reactant back. Chemical Reaction → Chemical reaction is the process by which two or more substance react with each other to form new substance with different properties. → These are the following changes to determine that the chemical reaction has taken place: (i) Change in state (ii) Change in colour (iii) Evolution of gas (iv) Change in temperature Chemical Equation → A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and formulae, wherein the reactant entities are given on the left-hand side and