Question

What is the coefficient in a chemical equation?

Answer 1

Coefficients are the numbers or terms used to balance chemical equations and are placed in front of a chemical symbol or formula. It tells us about how many atoms or molecules of substance or compound are involved in the reaction.

Complete answer: -As in mathematics, coefficient is the number used in front of a variable similarly in chemistry, coefficient is a number used in chemical equation, just as a prefix of chemical formula to define the number of molecules reacting and producing in a reaction.
-Suppose $3N{{H}_{3}}$ means 3 molecules of ammonia and 2HCl means 2 molecules of hydrogen chloride.
-Let's understand it better with the help of an example:-
$2{{H}_{2}}+1{{O}_{2}}\to 2{{H}_{2}}O$
We have the following coefficients in the above reaction:-
(a)2 in front of ${{H}_{2}}$
(b)1 in front of ${{O}_{2}}$
(c)2 in front of ${{H}_{2}}O$
From this reaction we can conclude that 2 molecules of hydrogen gas and 1 molecule of oxygen gas reacted to produce 2 molecules of water.
-Coefficients are very useful in balancing a chemical equation which plays an important role while dealing with the concentration terms. We add coefficients to balance the equation so as to assure that law of conservation of mass is being followed.

Note: Whenever you balance chemical equations, never make changes in the subscripts of chemical formulas as changing them will change the substance completely while being involved in the reaction. Only change the coefficients.