Acids , bases and salt

• Acids are sour in taste and change the colour of blue litmus to red
• Bases are better and change the colour of red litmus to blue
• Litmus is a natural indicator
• Examples of natural indicator are litmus , red cabbage leaf extract ,flowers of hydrangea plant ,turmeric
• Examples of synthetic indicators are phenolphthalein , methyl orange
• Examples of all factory indicators are onion , vanilla essence and clove oil
• Indicators who helps us to identify whether a substance is acidic or basic in nature by changing the smell are called olfactory indicators
• In the reaction of zinc granules with dilute sulphuric acid hydrogen gas is formed
• The reaction between an acid and metal give salt and hydrogen gas
• Example of reaction between acid and metal is 2NaOH + zinc gives Na2ZnO2 (sodium zincate) + H2
• On passing the carbon dioxide gas evolved through lime water we get calcium carbonate which is a white precipitate
• Passing access carbon dioxide to calcium carbonate we get calcium hydrogen carbonate
• The different forms of calcium carbonate are limestone chalk and marble
• Metal carbonate or metal hydrogen carbonate reacts with acid to give salt + carbon dioxide + water
• Basis and acids react with each other to give salt + water
• The reaction between an acid and base to give a salt and water is known as neutralization reaction
• The colour of dilute HCl becomes blue green when copper oxide is dissolved. The blue green colour of the solution is due to the formation of copper II chloride in the reaction.
• Metal oxide reacts with acid to give salt + water
• Metallic oxides are basic in nature and non metallic oxides are acidic in nature
• Glucose and alcohol solutions do not conduct electricity
• Hydrogen ions cannot exist allowed but the exist after combining with water molecules
• The separation of h+ iron from HCL molecules cannot occur in the absence of water
• Asus gives hydronium ions or h+ ions in water when dissolved
• Bases generate hydroxide ions in water
• Basis which are soluble in water are called alkalis
• Mixing and acid or base with water results in a decrease of concentration of ions per unit volume
• The process in which an acid or base is mixed with water is known as dilution
• A scale for measuring hydrogen ion concentration in a solution is called pH scale
• The pH of a neutral solution is 7
• The pH of an acidic solution is less than 7
• The pH of a basic solution is more than 7
• Acidic solutions have more H+ ions than OH- ions
• Basic solutions have more OH- ions than H+ ions
• Acidic solutions have low pH values, while alkaline solutions have high pH values.
• Strong acids are completely dissociated into H+ and A- ions when they dissolve in water
• Neutral solutions contain equal number of H+ ions and OH- ions
• A weak base is not fully dissociated into Na+ and OH- ions when it dissolves in water
• A strong base is fully dissociated into Na+ and OH- ions when it dissolves in water
• The acidity of a solution and increase of h+ ions is directly proportional
• The pH of our body is 7.0 - 7.8