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Balancing chemical equations: A complete guide

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Balancing chemical equations: A complete guide

Balancing chemical equations is important to master if you are pursuing chemistry!

Chemistry is all about equations, and most importantly, you need to balance them to master the subject. Many aspects of chemistry, such as stoichiometry, reaction analysis, and lab labour, rely on this crucial skill. 

 

How to balance, and why is it necessary?

 

The procedure of balancing is significant because a chemical equation must follow the laws of conservation of mass and constant proportions, which means that the reactant and product sides of the formula must have the same number of atoms of each element.

‘Everything in life has to have balance.’ –Donna Karan, and this is true with chemistry as well. We’ll go over a thorough guide on balancing chemical equations in this blog. Chemical reactions modify the composite parts of material rather than the building blocks themselves.

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How to proceed with the balance of equations

 

There are various methods to balance a chemical equation, and we will go through each one of them. They are:

 

  1. Inspection method: What do you mean by Inspection? It means to check something, and it goes with the Inspection method. It’s what it says on the tin. By examining the equation, you can find the right balance. For better understanding, let us understand the procedure and then take an example:

 

  • Imagine that the reaction involves only one molecule of this chemical. You have to start with the most complex compound.
  • Try to balance the atoms in the fewest number of compounds. You can use fractions as well.
  • At the end of most compounds, you have to balance atoms.
  • Eliminate fractions and determine the group of minimal coefficients once all atoms and charges are equal. It was the complete balancing procedure by the Inspection method. 

 

Let us take an example now:

 

  • NaCl + BeF2 → NaF + BeCl2 
  • Here, Cl appears to be imbalanced as you can see that they are not equal on both sides of the equation whereas, Na seems to be perfect. As a result, we’ll put number 2 next to NaCl as follows:
  • 2 NaCl + BeF2 → NaF + BeCl2 
  • Since Na on the right-hand side is no more equal to the left side, the equation gets uneven. We’ll need to add a 2 in front of NaF too. Thus, the equation becomes, 
  • 2 NaCl + BeF2 → 2 NaF + BeCl2 

 Now, you can see that atom counts on both sides are equal, and hence, we completed the balancing part. This method is easy, but it does not apply to all the equations. We need to see other ways to solve complex equations.

 

  1. Algebraic method: This may sound hard to understand, but it is not. Follow the below steps, and you’ll love it:

 

  • Besides each compound in the equation, write a unique character coefficient.
  • On both sides, write algebraic formulas or rules that correlate the atoms of each component.
  • Replace and reduce to generate a two-letter coefficient equation that you can utilize.
  • To get the balance ratios, substitute the values into the other rules.
  • For clearing concepts, take a look at an example:
  • CaCO3+H3PO4→Ca3(PO4)2+H2CO3 
  • For the coefficients, you first create the solution using letter factors:
  • aCaCO3+bH3PO4→cCa3(PO4)2+dH2CO3
  • Create a series of parallel equations, one for each element
  • Ca; a=3c, C; a=d, O; 3a+4b=8c+3d, H; 3b=2d, P; b=2c

 

 

 

  • Now you must solve the five equations mentioned earlier, and after solving, you get a=3; b=2; c=1; d=3. Now put the values of a, b, c in the question equation, and the result is 3CaCO3+2H3PO4→Ca3(PO4)2+3H2CO3

 

  • The most ubiquitous method is the algebraic method, also known as the material balance method. It balances all types of reactions. The improved version of the approach allows for a significant reduction in algebraic equations and is suited for managing intricate redox reactions.

 

These were the two methods to balance a chemical equation. However, there is a term redox which is very common in chemistry. Balancing a redox equation is another vital task, and it has considerable weightage in competitive and board exams.

 

What is a redox reaction?

Before understanding how to balance a redox equation, learn about redox reactions. Any chemical process in which the oxidation number of a given reactant and product changes is an oxidation-reduction reaction, which is also called a redox reaction. The majority of oxidation-reduction (redox) reactions involve the exchange of oxygen, hydrogen, or electrons. 

The word refers to a broad range of operations such as rusting around you is an example of this type of reaction.

 

Balancing a redox equation

 

To balance redox processes, the Half-Equation Method is acceptable. When dealing with redox reactions, three circumstances arise. Some conditions are acidic, while others are basic and neutral. Let us consider an example of a redox equation:

 

  • NH3 + NO2 —> N2O + H2O
  • Split the reaction into two.
  • NH3 —> N2O

 

NO2 —> N2O

 

  • In an acidic solution, maintain equilibrium.
  • H2O + 2NH3 —> N2O + 8H+ + 8e¯

            6e¯ + 6H+ + 2NO2 —> N2O + 3H2O

 

  • Equilibrate the electrons as shown:
  • 3H2O + 6NH3 —> 3N2O + 24H+ + 24e¯} *3

            24e¯ + 24H+ + 8NO2 —> 4N2O + 12H2O} *4

 

 

  • Add and remove similar items:
  • 6NH3 + 8NO2 —> 7N2O + 9H2O

 

Key Takeaways 

Unbalanced chemical equations inform us which substances react with one another and the result, making them non-preferable. Balanced equations are necessary because they form the foundation of all chemistry. So, pay attention and don’t try to memorize because you’ll be having a new equation to balance each time.


Also published on Medium.

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