1. Chemical Reactions: Chemical reactions are the changes that leads to one or more new substances.
i.e., reactants ------------> products
(i) Reactants: Reactants are the substances that take part in a reaction to produce new substance/substances.
(i) Products: Products are the new substances produced as a result of chemical change.
2. Chemical Equations: Chemical equations are representation of chemical changes in terms of symbols and formulae of reactants and products.
3. Balancing an equation: Equalising the number of atoms in both the reactants and products.
4. Balanced Chemical Equation: Chemical equation having same number of atoms in both the reactants and products.
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TYPES OF CHEMICAL REACTIONS:
1. Combination Reaction: The reaction in which two or more substances combine together to form a single substance.
e.g., 2Mg(s) + O2(g) --------->2MgO(s)
1. Combination Reaction: The reaction in which two or more substances combine together to form a single substance.
e.g., 2Mg(s) + O2(g) --------->2MgO(s)
2. Decomposition Reaction: The reaction in which single compound breaks up into two or more compounds.
e.g., 2Pb(NO3)2 (s) --------->2PbO (s) + 4NO2 (g) + O2 (g)
This reaction can be divided into three subcategories,
i.e.,
(i) Electrolysis
(ii) Thermal
(iii) Photochemical
e.g., 2Pb(NO3)2 (s) --------->2PbO (s) + 4NO2 (g) + O2 (g)
This reaction can be divided into three subcategories,
i.e.,
(i) Electrolysis
(ii) Thermal
(iii) Photochemical
3. Displacement Reaction: The reaction in which more reactive element displace the less reactive element to form to form a compound.
e.g., Cu (s) + 2AgNO3 (aq) ----------> Cu(NO3)2 (aq) + 2Ag (s)
e.g., Cu (s) + 2AgNO3 (aq) ----------> Cu(NO3)2 (aq) + 2Ag (s)
4. Double Displacement Reaction: The chemical reaction in which compound reacts to form different compound by mutual exchange of ions.
It can be divided into two types,
_(i) Precipitation: This reaction occur if we two aqueous solution of salt.
e.g., AgNO3 (aq) + NaCl (aq) -----------> NaCl (aq) +H2O
.(i) Neutralization: In this reaction acid reacts with base.
e.g., NaOH (aq) + HCl (aq) -----------> NaCl (aq) + H2O (aq)
It can be divided into two types,
_(i) Precipitation: This reaction occur if we two aqueous solution of salt.
e.g., AgNO3 (aq) + NaCl (aq) -----------> NaCl (aq) +H2O
.(i) Neutralization: In this reaction acid reacts with base.
e.g., NaOH (aq) + HCl (aq) -----------> NaCl (aq) + H2O (aq)
5. Redox Reaction: This reaction consists of two sub reaction,
i.e., (i) Oxidation: It involves gain of oxygen and loss of hydrogen.
___(ii) Reduction: It involves loss of oxygen and gain of hydrogen.
Both of this reaction take part mutually.
e.g., ZnO + C -----------> Zn + CO
Here, ZnO reduce to Zn_____reduction
and C oxydize to CO______oxidation
i.e., (i) Oxidation: It involves gain of oxygen and loss of hydrogen.
___(ii) Reduction: It involves loss of oxygen and gain of hydrogen.
Both of this reaction take part mutually.
e.g., ZnO + C -----------> Zn + CO
Here, ZnO reduce to Zn_____reduction
and C oxydize to CO______oxidation
6. Thermal Reaction
(i) Exothermic Reaction: This reaction involves releasing of heat.
e.g., C + O2 -----------> CO2 (g) + ∆
(ii) Endothermic Reaction: This reaction involves absorption of heat.
e.g., CaCO3 + ∆ ---------> CaO + CO2
(i) Exothermic Reaction: This reaction involves releasing of heat.
e.g., C + O2 -----------> CO2 (g) + ∆
(ii) Endothermic Reaction: This reaction involves absorption of heat.
e.g., CaCO3 + ∆ ---------> CaO + CO2
