Acids, Bases and Salts
Frequently Asked Questions
Acids are substances that contain hydrogen and can donate hydrogen ions (H+) to other substances. They have a sour taste and turn blue litmus paper red.
Bases are bitter, slippery to touch, turn red litmus blue, and neutralize acids in chemical reactions.
Salts are ionic compounds formed when acids react with bases or metals, consisting of cations from the base and anions from the acid.
A neutralization reaction is when an acid reacts with a base to form a salt and water, cancelling out each other's properties.
pH < 7 means acidic, pH = 7 is neutral, and pH > 7 is basic.
Indicators are substances like litmus, phenolphthalein, and methyl orange that change color in acids and bases to identify their nature.
The formula is NaHCO3 and it is mainly used in baking and as an antacid.
Hydrochloric acid aids digestion in the stomach and maintains a low pH to help break down food.
Strong acids/bases completely ionize in water; weak acids/bases only partially ionize. Examples: HCl (strong acid), CH3COOH (weak acid).
Water of crystallization is the fixed number of water molecules chemically bonded with salts in their crystalline form.
Dilution involves adding water to an acid to lower its concentration, making it safer for use and handling.
Always add acid to water slowly with stirring to avoid splashes and excessive heat which can cause burns or break glass.
Ant stings inject formic acid causing pain; applying a base like baking soda neutralizes the acid and gives relief.
Bleaching powder (CaOCl2) is used for disinfecting water, bleaching laundry, and as an oxidising agent in chemical industries.
It is prepared by heating gypsum; used for making casts, sculptures, decorative designs, and filling wall cracks.
Used to remove permanent hardness of water, and in glass, soap, and paper industries.
Acids react with reactive metals displacing hydrogen ions which combine to form hydrogen gas.
Lime water turns milky due to the formation of insoluble calcium carbonate.
Citric acid in lemons and lactic acid in curd and sour milk.
Adding acid to water slowly with stirring prevents rapid, dangerous heat release and splashing.
pH controls processes like digestion, tooth health, plant growth, and industrial chemical reactions.
Sodium hydroxide, chlorine gas, and hydrogen gas are produced from brine electrolysis.
Acid + metal carbonate forms salt, water, and carbon dioxide gas.
Acids can sting or burn, bases can feel soapy but may cause irritation if concentrated. Both can damage tissue on prolonged contact.
Litmus: red in acid, blue in base; Methyl orange: red in acid, yellow in base.
Baking powder releases carbon dioxide when heated, making cakes and bread soft and spongy.
pH = 7 is neutral; pure water is a neutral solution.
It is blue when hydrated (CuSO4·5H2O) and turns white when anhydrous, making the water visible in a lab demonstration.
Salts can be neutral, acidic or basic; have varied uses like seasoning food, water softening, or as chemicals in labs.
pH is measured by pH paper or meters; important for testing acidity/basicity in the lab, environment, and industry.
