# Chemical Equations

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A series of free High School Chemistry Video Lessons.

In this lesson, we will learn

• How to write a chemical equation from a word equation
• How to balance a chemical equation

Chemical Equation
A chemical equation shows the reactants and the products of a chemical reaction. Balancing chemical equations is necessary because the same atoms should be present before and after the reaction, just in different arrangements. A balanced chemical equation is useful in showing us the ratios of reactants and products.

How to write a skeletal chemical equation?
Examples:
potassium chlorate → potassium chlorate + oxygen
aluminum + oxygen → aluminum oxide
sodium carbonate + calcium cyanide → sodium cyanide + calcium carbonate

How to write a chemical equation from a word equation?
Chemical Change
• When compounds react, they are chemically changed into new compounds.
• Every chemical change can be communicated symbolically using a chemical equation.
• Chemical equations combine formulas with other symbols to show what changes take place.
Example:
Write a word equation for each of the following:
Al(s) + CuCl2(aq) → Cu(s) + AlCl3(aq)
CH4(g) + O2(g) → H2)(g) + CO2(g)
BeCl2(aq) + 2AgNO3(aq) → Be(NO3)2(aq) + 2AgCl(s)

Write a chemical equation for each of the following:
• Solid copper reacts with a solution of silver nitrate to produce solid silver and a solution of copper(II) nitrate.
• Solutions of sodium hydroxide and calcium bromide react to produce a solution of sodium bromide and solid calcium hydroxide.
• Solid lithium reacts with oxygen gas to produce solid lithium oxide.

How to easily write chemical equations?
Steps for writing Chemical Equations.

1. Identify the reactants and the products.
2. Write formulas for everything.
3. Place the reactants on the left.
4. Place the products on the right.
5. Place an arrow between them.

Example:
Aluminum reacts with phosphoric acid to yield hydrogen gas and aluminum phosphate.
Aluminum reacts with oxygen to form aluminum oxide.
Dinitrogen pentoxide reacts with water to produce nitric acid.
Sodium bicarbonate produces sodium carbonate, water and carbon dioxide.

Balancing Chemical Equations
Balancing chemical equations allows us to find the proper ratios of reactants and products within a chemical equation. In a balanced chemical equation, the same atoms are present on each side of the equation, but simply rearranged. A balanced chemical equation has the same number of atoms of each element on both reactant and product sides of the equation.

How to balance a chemical equation?
This video explains the basics of balancing chemical equations.
A visual guide shows you how to change coefficients to balance the atoms in reactants and products.

Balancing Chemical Equations
A chemistry tutorial designed to help learn the basic principles of balancing chemical equations, along with examples and methods of balancing different chemical equations.
Start by balancing those elements that occur in only one compound on each side of the equation.
You can only change the coefficients while balancing chemical reactions, never the subscripts.

Try the free Mathway calculator and problem solver below to practice various math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations. 