Chemistry Formulas

Chemical Reaction Formula


Chemical Reaction

Chemical Reaction Formula- it contains the reorganizing of atoms of the same or different elements to form new substances. Generally, we represent it with a chemical equation in which the reactants (substances that are broken apart) are written on the left and the products (a new substance that form) are written on the right. Furthermore, it the resulting product or the reactant are more than two then we separate them with a + sign. Moreover, we use an arrow (→) to separate the reactant side of the equation with the product side.

Chemical Reaction Formula

Common Symbol

There are certain symbols that we use to distinguish between different types of reactions. These symbols are:

We use the ‘=’ symbol to denote a stoichiometric reaction.

The arrow ‘→’ symbol denotes a net forward reaction.

The right-left arrow symbol denotes a reaction in both directions.

Also, we use \(\rightleftharpoons\) symbol to denote an equilibrium.

We can also state the physical state of chemical in parentheses after the chemical symbol, especially for ionic reactions. Furthermore, when stating the physical state the letter ‘s’ denotes solid, ‘l’ denotes a liquid, and ‘g’ symbolizes a gas, and ‘aq’ denotes an aqueous solution.

However, if the reaction requires energy then we indicate it above the arrow. We use the capital letter delta (\(\Delta\)) which we put on the reaction arrow to show that energy in the form of heat is added to the reaction. We use \(h\nu\)  if we add energy in the form of light. Moreover, we use other specific symbols for other types of energy or radiation.

Balancing a chemical equation

The law of conservation of mass states that the amount of elements does not change in a chemical reaction, which means each side of the chemical equation must represent the same quantity of any particular element. In the same way, the chemical reaction conserves the charge. So, both sides of the equation must present a balanced equation.

We can balance the simple equation by inspection, i.e. by trial and error. In addition, another technique involves solving a system of linear equations. Furthermore, the balanced equation is written with the smallest whole-number coefficients. Most noteworthy, if there is no coefficient then the coefficient is 1.

For example: we can balance the burning of methane by putting a coefficient 1 before CH4:

1 CH4 + O2 → CO2 + H2O

As both sides of the arrow have one carbon atom so the equation is balanced.

Ionic equations

These are chemical equations in which we can write electrolytes as distant ions. Moreover, we use ionic reactions for single and double displacement reactions that occur in aqueous solutions.

For example: The following precipitation reaction:

\(CaCl_{2} + 2AgNO_{3} \rightarrow CA(NO_{3})_{2} + 2AgCl\downarrow\)

Besides, the full ionic equation is:

\(Ca^{2+} + 2Cl^{-} + 2Ag^{+} + 2NO_{3}^{-} \rightarrow Ca^{2+} + 2NO_{3}^{-} +2AgCl \downarrow\)

However, in this reaction, the \(Ca^{2+}\) and \( NO_{3}^{-}\) ions remain in solution and are not part of the reaction. That means both these ions are identical in the reactant side and the product side of the chemical equation. This happens because these ions do not participate in this reaction, and are referred to as spectator ions. Also, a net ionic equation is the full ionic equation from which we have distant the spectator ions. Furthermore, the net ionic equation of the proceeding reaction is:

\(2Cl_{-} + 2Ag^{+} \rightarrow 2AgCl \downarrow\)

Or in reduced balanced form it is:

\(Cl_{-} + Ag^{+} \rightarrow AgCl \downarrow\)

Solved Example For You

Question: Show the reaction of methane (CH4) and oxygen (O2) and their products?

Solution: When methane reacts with oxygen it produces carbon dioxide and water. The reaction is:

\(CH^{4} + 2O^{2} → CO^{2} + 2H^{2}O\)

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