notes of chemical reaction and equations

COMBINATION REACTION - when two or more substances combine to form a single
product,the reactions are called combination reaction.Reactions in which heat is
released along with the formation of products are called exothermic chemical
reactions. for ex - CaO(s) + H2O(l) -->
Ca(OH)2(aq)

(quick Lime) (water) (slaked lime)

DECOMPOSITION REACTION - single reactant breaks down to give simpler products.When
a decomposition reaction is carried out by heating,it is called thermal
decomposition. for ex -
Heat
IN PRESENCE OF HEAT - CaCo3(s) ------------------> CaO(s) +
CO2(g)
(limestone)
(quick lime)

DISPLACEMENT REACTION - In this reaction there will be one element and other will
be compound.Colour change takes place.
for ex -

Fe(s) + CuSO4(aq)--------------> FeSO4(aq) + Cu(s)
(copper sulphate) (iron sulphate)

DOUBLE DISPLACEMNT REACTION - double displacement reaction also known as
precipitation reaction or ppt reaction in which any reaction that produces a
precipitate can be called a precipitation reaction.

:- ppt reacts compund and compound.
:- 2 displacement and iron exchange is ussually accompained by ppt

for ex - Na2SO4(aq) + BaCL2(aq)
----------------> BaSO4(s) + 2NaCl(aq)
(sodium sulphate) (barium chloride)
(barium sulphate) (sodium chloride)


OXIDATION AND REDUCTION -

OXIDATION - gains O2 and removes H2
for ex - CuO(s) + H2(g) → Cu(s) + H2O(l)

CuO adds oxygen to H2; CuO is therefore the oxidizing agent or oxidant, it oxidizes
the H2 to H2O


REDUCTION - gains H2 and removes O2
for ex - Zn(s) + 2H+(aq) → Zn2+(aq) + H2(g)

Rusting of iron is a process that involves oxidation and reduction. Oxygen is
reduced, while iron is oxidized.

ENDOTHERMIC REACTION - Endothermic reactions are chemical reactions in which the
reactants absorb heat energy from the surroundings to form products

for ex - Melting ice cubes. Melting solid salts. Evaporating liquid water.
Converting frost to water vapor (melting, boiling, and evaporation, in general, are
endothermic processes