Writing chemical reaction
A chemical equation consists of the chemical formulas of the reactants (on the left) and the products (on the right). The two are separated by an arrow symbol ("" usually read aloud as "yields"). Each individual substance's chemical formula is separated from others by a plus sign. The state of matter, i.e., solid, liquid, gas or aqueous, of each compound or molecule is indicated in subscript next to the compound by an abbreviation in parentheses. For example,
Applictions of redox reaction
Extraction of metals: can be done by using redox reaction concept.
Electrochemical cells : these type of batteries based on redox reactions are widely used in our day to day life. Photosynthesis : Green plants covert COand water in glucose in presence of sunlight and chlorophyll is redox reaction.
Electrochemical cells : these type of batteries based on redox reactions are widely used in our day to day life. Photosynthesis : Green plants covert COand water in glucose in presence of sunlight and chlorophyll is redox reaction.
Reactants and products
The raw materials that react with each other are known as reactants. Under the proper conditions, such as temperature, time, or pressure, the chemical bonds of the reactants are broken, and the atoms form new bonds that give different combinations. The substances that result from this recombination of atoms are called the products of the reaction. For example,
Reactants are on left side and products are on right hand side of the arrow.
Reactants are on left side and products are on right hand side of the arrow.
Balancing of chemical equation by hit and trial method
In this method of balancing chemical equations, trials are made to balance the equation by using the smallest whole number coefficient. Hence, this method is called the hit and trial method.
(i) Count the number of times an element occurs on both sides.
(ii) An element with the least frequency of occurrence is balanced first.
(iii) When two or more elements have same frequency, metallic elements are balanced first.
(i) Count the number of times an element occurs on both sides.
(ii) An element with the least frequency of occurrence is balanced first.
(iii) When two or more elements have same frequency, metallic elements are balanced first.
Steps for balancing chemical reaction
To balance a chemical reaction, following steps should be followed:
1. Check for diatomic molecules
2. Balance the metals (not hydrogen) and nonmetals (not oxygen)
3. Balance oxygen and hydrogen
4. The equation should now be balanced, but recount all atoms to be sure
5. Reduce coefficients (if needed). All coefficients must be reducible before you can reduce. An equation is not properly balanced if the coefficients are not written in their lowest whole-number ratio.
Procedures to solve chemical reactions
(i) Write the symbols or the formulae of the reactants on the left hand side, with a (+) sign between them.
(ii) Write the symbols or the formulae of the products on the right hand side, with a (+) sign between them.
(iii) Put the sign of an arrow () in between the reactant side and the product side.
(iv) It represent the reactants and the products in their molecular forms [because their atomic forms are usually neither stable nor capable of separate existence .
A chemical equation tells us what substances enter a given reaction (REACTANTS) and what substances are formed as a result of the reaction (PRODUCTS).
(ii) Write the symbols or the formulae of the products on the right hand side, with a (+) sign between them.
(iii) Put the sign of an arrow () in between the reactant side and the product side.
(iv) It represent the reactants and the products in their molecular forms [because their atomic forms are usually neither stable nor capable of separate existence .
A chemical equation tells us what substances enter a given reaction (REACTANTS) and what substances are formed as a result of the reaction (PRODUCTS).
Problem on balancing a chemical reaction by hit and trial method
Balance chemical reaction. .
Step 1. Balance number of oxygen atoms on both sides. So on reactant side there are 6 oxygen atom are there so multiplying product side with 3.
Step 2. Balance number of hydrogen atom. Now it became 12 hydrogen atom on product so multiply reactant by 3.
Balanced reaction become.
Step 1. Balance number of oxygen atoms on both sides. So on reactant side there are 6 oxygen atom are there so multiplying product side with 3.
Step 2. Balance number of hydrogen atom. Now it became 12 hydrogen atom on product so multiply reactant by 3.
Balanced reaction become.
Balancing of chemical equation by partial equation method
When equations contain many reactants and products they cannot be balanced by the hit and trial method. They are then balanced by the partial equation method. In this method the overall reaction is assumed to take place through two or more simpler reactions, which can be represented by partial equations. The steps involved are:
- The given chemical equation is split into two or more partial equations.
- Each partial equation is separately balanced by the hit and trial method.
- These balanced partial equations are multiplied with suitable coefficients in order to exactly cancel out those common substances which do not appear in the overall chemical equations.
- The balanced partial equations so obtained, are added to arrive at the balanced chemical equation
Partial equation method
In Partial equation method, the overall reaction is assumed to take place through two or more simpler reactions, which can be represented by partial equations. The steps are:
The given chemical equation is split into two or more partial equations.
Each partial equation is separately balanced by the hit and trial method.
These balanced partial equations are multiplied with suitable coefficients in order to exactly cancel out those common substances which do not appear in the overall chemical equations.
The balanced partial equations so obtained, are added to arrive at the balanced chemical equation
The given chemical equation is split into two or more partial equations.
Each partial equation is separately balanced by the hit and trial method.
These balanced partial equations are multiplied with suitable coefficients in order to exactly cancel out those common substances which do not appear in the overall chemical equations.
The balanced partial equations so obtained, are added to arrive at the balanced chemical equation
Decomposition reaction
A decomposition reaction is a type of chemical reaction in which a single compound breaks down into two or more elements or new compounds. These reactions often involve an energy source such as heat, light, or electricity that breaks apart the bonds of compounds. For example,
Electrochemical reaction
An electrochemical reaction is a process in which electrons flow between a solid electrode and substance, such as an electrolyte. This flow triggers an electric current through the electrodes, causing the reaction to liberate or absorb heat.
is a simple electrochemical reaction.
is a simple electrochemical reaction.
Reaction of acids with bases
Acid-base neutralization reaction is a reaction in which an acid reacts with a base to form salt and water. Poly-functional acids and bases, when react together there can be normal, acidic and basic salts that are formed.
An acidbase titration is the determination of the concentration of an acid or base by exactly neutralizing the acid or base with an acid or base of known concentration.
An acidbase titration is the determination of the concentration of an acid or base by exactly neutralizing the acid or base with an acid or base of known concentration.
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