Why must all chemical equations be balanced

I think the most essential part of the answer is "the law of conservation of mass". Post by Nathan Mariano 2G » Sat Nov 24, am We balance chemical equations due to the law of conservation of mass, which states that mass can neither be created or destroyed.

Therefore, in a chemical reaction, the total mass of the reactants must be equal to the total mass of the products. Balancing equations accounts for the total mass of the reactants and the total mass of the products. Post by Jack Hewitt 2H » Fri Dec 07, am Madelyn Cearlock wrote: For the question that asks why do we balance chemical equations, what was the exact answer that was desired? Post by duenezjuleny1D » Wed Jun 26, pm We want to make sure not break the law of conservation of mass.

It is important to balance on each side, the products and the reactants. Post by Brian Kwak 1D » Wed Jun 26, pm It is because of the concept of conservation of mass which states that in an isolated system mass can not be created nor destroyed by chemical reactions or physical transformations.

Since the chemical reaction can not destroy or create mass the number of elements from the reactants must equal the number of elements that are produced. Also my TA said not to assume every chemical equation we get on the exam will be balanced. Join thousands of students and gain free access to 46 hours of Chemistry videos that follow the topics your textbook covers.

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On the product side right side , there are one atom of carbon, two atoms of hydrogen, and three atoms of oxygen. Therefore, the equation does not satisfy the law of conservation of mass, and is not balanced.

In order to balance the equation, we must change the amounts of the reactants and products, as necessary, by adding coefficients in front of the appropriate formula s. To determine the number of atoms of each element, the coefficient is multiplied times the subscripts in each formula.

If there is no coefficient or subscript, it is understood to be 1. The balanced equation for the combustion of methane is:. If you compare the unbalanced equation to the balanced equation, you will see that the chemical formulas of each reactant and product were not changed.

The only change is the coefficient of 2 written in front of the formula for oxygen on the reactant side, and the coefficient of 2 written in front of the formula for water on the product side. So now there are one carbon atom, four hydrogen atoms, and four oxygen atoms on both sides of the equation, and the equation is balanced.