MCQ Detailed View

In chemistry, every chemical reaction is represented by a balanced chemical equation, which shows the exact proportions of reactants and products involved. When calculations are performed based on these equations, they can predict the maximum amount of product that can be obtained if the reaction proceeds perfectly and completely converts all reactants to products. This maximum predicted amount is called the theoretical yield.

Theoretical yield is calculated using stoichiometric ratios, which come from the coefficients in a balanced equation. It assumes that:

• 
  

  All reactants are fully converted into products.

  
  


• 
  

  No material is lost during reaction or separation.

  
  


• 
  

  The reaction proceeds with 100% efficiency.

  
  

For example, if a chemical equation shows that 2 moles of hydrogen react with 1 mole of oxygen to produce 2 moles of water, the theoretical yield can be calculated exactly based on the amount of hydrogen and oxygen available.

In real laboratory or industrial conditions, reactions rarely achieve 100% efficiency. This is why actual yield (the real quantity of product obtained experimentally) is often less than the theoretical yield. The difference is due to incomplete reactions, side reactions, or losses during collection and purification.

The percentage yield compares actual yield to theoretical yield:

Percentage Yield (%)=Actual YieldTheoretical Yield×100\text{Percentage Yield (\%)} = \frac{\text{Actual Yield}}{\text{Theoretical Yield}} \times 100Percentage Yield (%)=Theoretical YieldActual Yield×100

Thus, while actual yield tells what was truly produced, and practical yield is sometimes used informally for real-world results, the term theoretical yield specifically refers to the maximum possible product predicted by stoichiometry under ideal conditions. It is a key concept for chemists to evaluate reaction potential and design efficient processes.