what is method of balancing chemical equation ?????
Answers
Answer:
The first step that must be followed while balancing chemical equations is to obtain the complete unbalanced equation. In order to illustrate this method, the combustion reaction between propane and oxygen is taken as an example.
Step 1
The unbalanced equation must be obtained from the chemical formulae of the reactants and the products (if it is not already provided).
The chemical formula of propane is C3H8. It burns with oxygen (O2) to form carbon dioxide (CO2) and water (H2O)
The unbalanced chemical equation can be written as C3H8 + O2 → CO2 + H2O
Step 2
The total number of atoms of each element on the reactant side and the product side must be compared. For this example, the number of atoms on each side can be tabulated as follows.
Chemical Equation: C3H8 + O2 → CO2 + H2O
Reactant Side Product Side
3 Carbon atoms from C3H8 1 Carbon atom from CO2
8 Hydrogen atoms from C3H8 2 Hydrogen atoms from H2O
2 Oxygen atoms from O2 3 Oxygen atoms, 2 from CO2 and 1 from H2O
Step 3
Now, stoichiometric coefficients are added to molecules containing an element which has a different number of atoms in the reactant side and the product side.
The coefficient must balance the number of atoms on each side.
Generally, the stoichiometric coefficients are assigned to hydrogen and oxygen atoms last.
Now, the number of atoms of the elements on the reactant and product side must be updated.
It is important to note that the number of atoms of an element in one species must be obtained by multiplying the stoichiometric coefficient with the total number of atoms of that element present in 1 molecule of the species.
For example, when the coefficient 3 is assigned to the CO2 molecule, the total number of oxygen atoms in CO2 becomes 6. In this example, the coefficient is first assigned to carbon, as tabulated below.
Chemical Equation: C3H8 + O2 → 3CO2 + H2O
Reactant Side Product Side
3 Carbon atoms from C3H8 3 Carbon atoms from CO2
8 Hydrogen atoms from C3H8 2 Hydrogen atoms from H2O
2 Oxygen atoms from O2 7 Oxygen atoms, 6 from CO2 and 1 from H2O
Step 4
Step 3 is repeated until all the number of atoms of the reacting elements are equal on the reactant and product side. In this example, hydrogen is balanced next. The chemical equation is transformed as follows.
Chemical Equation: C3H8 + O2 → 3CO2 + 4H2O
Reactant Side Product Side
3 Carbon atoms from C3H8 3 Carbon atoms from CO2
8 Hydrogen atoms from C3H8 8 Hydrogen atoms from H2O
2 Oxygen atoms from O2 10 Oxygen atoms, 6 from CO2 and 4 from H2O
Now that the hydrogen atoms are balanced, the next element to be balanced is oxygen. There are 10 oxygen atoms on the product side, implying that the reactant side must also contain 10 oxygen atoms.
Each O2 molecule contains 2 oxygen atoms. Therefore, the stoichiometric coefficient that must be assigned to the O2 molecule is 5. The updated chemical equation is tabulated below.
Chemical Equation: C3H8 + 5O2 → 3CO2 + 4H2O
Reactant Side Product Side
3 Carbon atoms from C3H8 3 Carbon atoms from CO2
8 Hydrogen atoms from C3H8 8 Hydrogen atoms from H2O
10 Oxygen atoms from O2 10 Oxygen atoms, 6 from CO2 and 4 from H2O
Step 5
Once all the individual elements are balanced, the total number of atoms of each element on the reactant and product side are compared once again.
If there are no inequalities, the chemical equation is said to be balanced.
In this example, every element now has an equal number of atoms in the reactant and product side.
Therefore, the balanced chemical equation is C3H8 + 5O2 → 3CO2 + 4H2O.
hope it helps !
Answer:
The steps for balancing a chemical equation are:
1. First, note down the elements on each side of the equation and their atoms.
2. Pick one element which isn’t equal on both sides of the equation and add a coefficient to the formula with the equation to make it equal.
3. Continue doing this until all the elements in the equation are balanced on both sides.
Eg: Mg + O2 = MgO (Here oxygen isn’t balanced because there are two atoms of oxygen on the LHS and one atom on the RHS)
=> Mg + O2 = 2MgO (Now Oxygen is balanced, but now magnesium is not balanced because now there is one atom of magnesium on the LHS and two atoms of magnesium on the RHS)
=> 2Mg + O2 = 2MgO ( Now the equation is balanced because both magnesium and oxygen are balanced)
Hope this helps!