YIELD
The amount of the substance calculated from balance chemical equation or produced as a result of chemical reaction is known as yield.
Types of Yield:
The types of yield are as follows.
i) Theoretical ii) actual yield
(i) Theoretical Yield:
The amount of product calculated from the balanced chemical equation is called theoretical yield. It is the maximum amount of product that should be produced according to the balanced chemical equation.
(ii) Actual Yield:
The amount of the product obtained experimentally as a result of chemical reaction is called actual yield.
Actual yield is mostly less than theoretical yield:
In most of the reactions, actual yield is lesser than the theoretical yield due to:
(i) Side reaction/ competing reaction.
(ii) Reversible reaction
(iii) Incomplete reaction
(iv) Inexperience worker
(v) Mechanical Loss of products during separation by
• Solvent extraction
• Filtration
• Distillation
• Crystallization
Actual yield may be lesser due to inefficiency during the washing and drying of crystals.
Percentage Yield:
The ratio of actual yield to theoretical yield multiplied by 100 gives us percentage yield. A chemist is usually interested in the efficiency of a reaction. The efficiency of the reaction is expressed in the form of percentage yield.