# Can anyone help on how to compare the reactions of acids and bases, as well as giving examples, and also how to specify the reactants and products?And finally, I need to produce a balanced equation.

bandmanjoe | Middle School Teacher | (Level 2) Senior Educator

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Well, lets take the neutralization of an acid and a base.  An acid is a substance that, upon addition to water, dissociates into hydrogen ions (H+).  A base is a substance that, upon addition to water, dissociates into hydroxide ions (OH-).  When you add an acid to a base, you get the production of a salt plus water.  Lets see how this is illustrated when you add hydrochloric acid (HCl) to sodium hydroxide (NaOH):

HCl  +  NaOH --->  NaCl  +  H2O

In this example, sodium chloride is the salt, and of course, water is the water that is produced.  This equation is balanced as is.  We know this by counting the number of atoms on each side of the yields sign, the arrow.  I teach my students to set the atoms up in two columns and account for them on either side of the yields sign, like this:

Reactants        Products

H                    2                     2

Cl                   1                     1

Na                  1                     1

O                    1                     1

When the numbers equal on both sides of the yields sign, the equation is balanced.  If the number of atoms does not equal, the equation is not balanced.  You must then use coefficients, which are big numbers in front of the compound which act as a multiplier.  Lets try the decomposition of hydrogen peroxide into water and oxygen gas:

H2O2  ---->   H2O  +  O2

Reactants     Products

H                       2                  2

O                       2                  3

As you can see, there are 3 atoms of oxygen on the products side and 2 on the reactants side.  If you use a coefficent of 2 in front of the water on the reactants side, that will give 4 oxygens on the reactants side.  If you go to the products side and put a coefficient of 2 in front of the hydrogen peroxide, that will not only give you 4 oxygens on that side, but also correct the 4 hydrogens that now exist on the products side.

2H2O2  ----->  2H2O  +  O2

Reactants   Products

H                       4                 4

O                       4                 4

Again, when the numbers equal across the yields sign, the equation is balanced.