| |
|
|
| |
 |
| Summary
|
|
- Acidic substances generate H+ ions in the medium, while basic ones liberate OH-
ions in the medium
- Certain dyes are used as indicators to detect the
presence of acids and bases
- Strength of an acid depends on the concentration of hydronium ions present in a solution. Greater the numbers of hydronium
ions present, greater is the strength of the acid
- A strong acid dissociates completely in water
Example: Hydrochloric acid
- A weak acid dissociates only partially when dissolved in water
Example: Acetic acid - Acids react with metals like Mg, Zn, Fe to give salt
and hydrogen
- Acids react with basic hydroxides, carbonates, sulphites and sulphides to give salt and a volatile gas such as carbon dioxide, sulphur dioxide and hydrogen sulphide,
as the case may be
- Strength of a base depends on the concentration of hydroxyl ions
- A strong base dissociates completely in water
Example: Sodium hydroxide
- A weak base dissociates partially in
water
Example: Ammonium hydroxide
- In neutralization reaction acids and bases neutralize
each other to form corresponding salts and water
- Acidic and basic solutions yield ions in solutions and so are good
conductors of electricity
- Mixing of acids and bases to water is an exothermic reaction generating
heat
- The strength of an acid or base is expressed on a 14 point scale
(ranges from 0 to 14) known as pH Scale
- An acidic solution has a pH less than 7 and a basic solution a pH more
than 7 while a neutral solution has a pH of exactly 7
- Living organisms carry all metabolic activities under optimum
conditions of pH. Agriculture and chemical industries also employ the pH
concept
- Salts are important compounds that are obtained by treating an acid
with a base. They are of many different types such as normal, acidic, basic,
mixed, double and complex
- Important salts used in everyday life and industrial applications are Sodium chloride (NaCl), Sodium carbonate, (Na2CO3), Sodium Bicarbonate, (NaHCO3), Sodium Hydroxide (NaOH)
- Water of crystallization is the number of molecules chemically combined in a definite molecular proportion with the salt in the crystalline state. This water is responsible for the geometric shape and colour
of the crystals
Example: Washing soda crystals or sodium carbonate decahydrate, Na2CO3.10H2O
- Certain substances like sodium chloride do not require the help of
water to form their crystalline shape
|
| |
|
|
| |
|
|
|
|
|
Get FREE Live Tutoring
(No credit card required)
|
|
|
