10th Class Chapter- Acids Bases and Salts
·
Natural indicator
of acids and bases – Litmus, Turmeric
·
Synthetic
indicator of acids and bases – Methyl Orange, Phenolphthalein
·
Olfactory
indicators of acids and bases - Odor of these substance changes in acids and
bases.
What is Acid?
Acids are the chemicals which
can donate a proton or accept an electron
pair in chemical reactions having pH less than 7 and changes color of blue
Litmus to red.
Example- HCl, H2SO4
What is Base?
Bases are the chemicals which
can accept a proton or donate an electron
pair in chemical reactions having pH more than 7 and changes color of red
Litmus to blue.
Bases which dissolve in water
are called as Alkali
Example- NaOH
What is Salt?
Example- NaCl
Acids and Bases Reaction with Metals:-
Metal react with acid to form salt.
Acid + Metal ------> Salt + Hydrogen Gas
Similarly,
Metal react with base to form salt.
Base + Metal ------> Salt + Hydrogen Gas
Reaction of Metal Carbonates and Metal Hydrogen-Carbonates with Acids:-
Metal carbonates and metal
hydrogen carbonates react with acids to form salt, water and carbon dioxide.
Metal Carbonate + Acid ----> Salt + Water + Carbon Dioxide
Example- Na2CO3
+ 2HCl -----> 2NaCl + H2O
+ CO2
Similarly,
Metal Hydrogen Carbonate +
Acid --à Salt + Water + Carbon
Dioxide
Example- NaHCO3 + HCl
-----> NaCl + H2O
+ CO2
Reaction of Acids with Bases:-
Reaction of acids with bases
to form salt and water is called neutralization reaction.
Acid + Base ----> Salt + Water
Reaction of Acids with Metallic Oxides:-
Acids react with Metallic
Oxides to form salt and water.
Acid + Metallic Oxide ----> Salt + Water
Reaction of Bases with Non-Metallic Oxides:-
Non-Metallic Oxides are
acidic in nature so these react with bases to form salt and water.
Base + Non-Metallic Oxide ----> Salt + Water
Acids or Bases in Water:-
When acids dissolve in water
they produce Hydrogen Ion H+(Aq) or Hydronium Ion (H3O+)
HCl + H2O --> H3O+ + Cl-
H+ + H2O
--> H3O+
When bases dissolve in water
they produce Hydroxide Ions (OH-)
NaOH + H2O ------> Na+(Aq) + OH-(Aq)
Reactions of Acids or Bases
with Water are highly exothermic. Process of mixing Acid or Base with water
decrease concentration of ions per unit volume, this process is known as dilution.
Strength of Acids or Bases:-
Strength of acids depends on
number of hydrogen ions (H+) produced and strength of bases depends
on number of hydroxide ions (OH-)
produced. A universal indicator (present on pH paper) is used to find strength
of acids or bases.
10 Class- Acids, Bases and Salts part-2
10 Class- Acids, Bases and Salts part-2
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