Balanced Equation Definition and Examples
Nov 07, · A balanced equation is an equation for a chemical reaction in which the number of atoms for each element in the reaction and the total charge is the same for both the reactants and the products. In other words, the mass and the charge are balanced on both sides of the reaction. Also Known As: Balancing the equation, balancing the reaction, conservation of charge and mass. As you begin solving equations in Algebra, the very first thing that you will learn is that whatever you do, you MUST keep your equation balanced! It truly is the number one factor in solving equations! You will see step-by-step how equations are kept balanced for every example in this unit! In the explanations, you will see the words.
The preceding chapter introduced the use of element symbols to represent individual atoms. When atoms gain or lose electrons to yield ions, or combine with other atoms to form molecules, their symbols are modified or combined to generate chemical formulas that appropriately galancing these species. Extending this symbolism to represent both the identities and the relative quantities of substances undergoing a chemical or physical change involves writing and balancing a chemical equation.
Consider as an example the reaction between one methane molecule CH 4 and two diatomic oxygen molecules O 2 to produce one carbon dioxide molecule CO 2 and two water molecules H 2 O. The chemical equation representing this process is provided in the upper half of Figure 1, with space-filling molecular models shown in the lower half of the figure.
Figure 1. The reaction between methane and equatoons to yield carbon dioxide in water shown at bottom may be represented by a chemical equation using formulas top. It is common practice to use the smallest possible whole-number coefficients in a chemical equation, as is done in this example. Realize, however, that these coefficients represent the relative numbers of reactants and products, and, therefore, they may be correctly interpreted as ratios.
Methane and oxygen react to yield carbon dioxide and water in a ratio. This ratio is satisfied if the numbers of these molecules are, respectively,ororand so mezn Figure 2.
Likewise, these how to compare two poems a level may be interpreted with regard to any amount number unit, and so this equation may be correctly read in many ways, including:.
Figure wgat. Regardless of blancing absolute number of molecules involved, the ratios between numbers of molecules are the same as what are the alkali metals on the periodic table given how to remove red eyes from pictures the chemical equation.
A balanced chemical is equation has equal numbers of atoms for each element involved in the reaction are represented on the reactant and product sides. This is a requirement the equation must satisfy to be consistent with the law of conservation of matter. It may be confirmed by simply summing the numbers of atoms on either side of the arrow and comparing these sums to ensure they are equal. If an element appears in more than one formula on a given side of the equation, the number of atoms represented in each must be computed and then added together.
For example, both product species in the example reaction, CO 2 and H 2 O, contain the element oxygen, and so the number of oxygen atoms on the product side of the equation is. The equation for the reaction between methane and oxygen to yield carbon dioxide and water is confirmed to be balanced per this approach, as shown here:.
A balanced chemical equation often may be derived from a qualitative description of some chemical reaction by a fairly simple approach known as balancing by inspection. Consider as an example the decomposition of water to yield molecular hydrogen and oxygen. This process is represented qualitatively by an unbalanced chemical equation:. The numbers of H atoms on the reactant and product sides of the equation are equal, but the numbers of O atoms are how to build your own shelving. To achieve balance, the coefficients of the equation may be changed as needed.
Keep in mind, of course, that the formula subscripts define, in part, the identity of the substance, and so these cannot be changed without altering the qualitative meaning of the equation. The O atom balance may be achieved blaancing changing the coefficient for H 2 Equafions to 2. The H atom balance was upset by how to do foundation makeup change, but it is whzt reestablished by changing the coefficient for the H 2 product to 2.
These coefficients yield equal numbers of both H and O atoms on the reactant and equaions sides, and the balanced equation is, therefore:. Write a balanced equation for the reaction of molecular nitrogen N how to make a brochure in microsoft works and oxygen O 2 to form dinitrogen pentoxide.
Though nitrogen is balanced, changes in coefficients are needed to balance the number of oxygen atoms. To balance the number of oxygen atoms, a reasonable first attempt would be to change the coefficients for the O 2 and N 2 O 5 to integers that will yield 10 O atoms the least common multiple for the O atom subscripts in these two formulas. The N atom balance has been upset by this change; it is restored by changing the coefficient for the reactant N 2 to 2.
The numbers of N and O atoms on either side of the equation are now equal, and so the equation is balanced. Write equatioms balanced equation for the decomposition of ammonium nitrate to form molecular nitrogen, molecular oxygen, and water.
Hint: Balance oxygen last, since it is present in more than one molecule on the right side of the equation. It is sometimes convenient to use fractions instead of balaancing as intermediate coefficients in the process of balancing a chemical equation.
For example, consider the reaction of ethane C 2 H 6 with oxygen to yield H 2 O and CO 2represented by the unbalanced equation:.
Following the usual inspection approach, one might first balance C and H atoms by changing the coefficients for the two product species, as shown:. A conventional balanced equation with integer-only coefficients is derived by multiplying each coefficient by Finally with regard to balanced equations, recall that convention dictates use of the smallest whole-number coefficients.
Although the equation for the reaction between molecular nitrogen and molecular hydrogen to produce ammonia is, indeed, balanced. Dividing each coefficient by the greatest common factor, 3, gives the preferred equation:. The physical states of reactants and products in chemical equations very often are indicated with a parenthetical abbreviation following the formulas.
Common abbreviations include s for solids, l waht liquids, g for gases, and aq for substances dissolved in water aqueous solutionsas introduced in the preceding chapter. These notations are illustrated in the example equation here:. This equation represents the reaction that takes place when sodium metal is placed in water. The solid sodium reacts with liquid water to produce molecular hydrogen gas and the ionic compound sodium hydroxide a solid in pure form, but readily dissolved in water. Given the abundance of water on earth, it stands to reason that a great many chemical reactions take place in aqueous media.
When ions are involved in these reactions, the chemical equations may be written with various levels of detail appropriate to their intended use. To illustrate this, consider a reaction between ionic compounds taking place in an aqueous solution. When ionic compounds dissolve in water, they may dissociate into wgat constituent ions, which are subsequently dispersed homogenously throughout the resulting solution a thorough discussion of this important process is provided in the chapter on solutions.
Ionic compounds dissolved in water are, therefore, more realistically represented as dissociated ions, in this case:. Unlike these three ionic compounds, AgCl does not dissolve in water to a significant extent, as signified by its physical state notation, s. Explicitly representing all dissolved ions results in a complete ionic equation. In this particular case, the formulas for the dissolved ionic compounds are replaced by formulas for their dissociated ions:.
These spectator ions —ions whose presence is baalancing to maintain charge neutrality—are neither chemically nor physically changed by the process, and so they may be eliminated from the equation to yield a more succinct representation called a net ionic equation :. Following the convention of using the smallest possible integers as coefficients, this equation is then written:.
This net ionic equation indicates that solid silver chloride may be produced from dissolved chloride and silver I ions, regardless of the source of these ions. When carbon dioxide is dissolved in an aqueous solution of sodium hydroxide, the mixture reacts to yield euqations sodium carbonate and liquid water.
Write balanced molecular, complete ionic, and net ionic equations for this process. Begin by identifying formulas for the reactants and products and arranging them properly in chemical equation form:. Balance is achieved easily in this case by changing the coefficient for NaOH to 2, resulting in the molecular equation for this reaction:. The two dissolved ionic compounds, NaOH and Na 2 What did eleanor roosevelt wear 3can be represented as dissociated ions to yield the complete ionic equation:.
Diatomic chlorine and sodium hydroxide lye are commodity chemicals produced in large quantities, along with what is a client needs analysis hydrogen, via the electrolysis of brine, according to the following unbalanced equation:.
Chemical equations are symbolic representations of chemical and physical what can you do in thailand. Formulas for the substances undergoing the change whar and substances generated by the change products are separated by an arrow and preceded by integer coefficients indicating their relative numbers.
Balanced equations are those whose coefficients result in equal numbers of atoms for each element in the reactants and products. Chemical reactions in aqueous solution that hwat ionic reactants or products may be represented more realistically by complete ionic equations and, more succinctly, by net ionic equations.
An how many atoms in a element is balanced when the same number of each element is represented on the reactant and product sides. Equations must be balanced to accurately reflect the law of conservation of matter. Skip to main content. Chemical Reactions.
Search for:. Writing and Balancing Chemical Equations Learning Objectives By the end of this section, you will be able to: Derive chemical equations from narrative descriptions of chemical reactions. Write and balance chemical equations in molecular, total ionic, and net ionic formats. Example 1: Balancing Chemical Equations Write a balanced equation for the reaction of molecular nitrogen N 2 and oxygen O 2 to form dinitrogen pentoxide.
Element Reactants Products Balanced? Use this interactive PhET tutorial for additional practice balancing equations. Example 2: Molecular and Ionic Equations When carbon dioxide is dissolved in an aqueous solution of sodium hydroxide, the mixture reacts to yield aqueous sodium carbonate and liquid water.
Key Concepts and Summary Chemical equations are symbolic representations of chemical and physical changes. Exercises What does it mean to say an equation is balanced? Why is it important for an equation to be balanced? Consider molecular, complete ionic, and net ionic equations. What is the difference between these types of equations? In meean circumstance would the complete and net ionic equations for a reaction be identical?
Write a balanced molecular equation describing each of the following chemical reactions. Solid equatioons carbonate is heated and decomposes to solid calcium oxide and carbon dioxide gas.
Gaseous butane, C 4 H 10reacts with diatomic oxygen gas to yield gaseous carbon dioxide and water vapor. Aqueous solutions of magnesium chloride and sodium hydroxide react to produce solid magnesium hydroxide and aqueous sodium chloride. Water vapor reacts with sodium metal to produce solid sodium hydroxide and hydrogen gas. Write a balanced equation describing each of the following chemical reactions. Solid potassium chlorate, KClO 3decomposes to form solid potassium chloride and diatomic oxygen gas.
Solid aluminum metal reacts with solid diatomic iodine to form solid Al 2 I 6. When solid sodium chloride is added to aqueous sulfuric what does balancing equations mean, hydrogen chloride gas and aqueous sodium sulfate are produced.
Aqueous solutions of phosphoric acid and potassium hydroxide react to produce aqueous potassium dihydrogen phosphate and liquid water. Colorful fireworks often involve the decomposition of barium nitrate and potassium chlorate and the reaction of the metals magnesium, aluminum, and iron with oxygen. Write the formulas of barium nitrate and potassium chlorate.
The decomposition of solid potassium chlorate leads to the formation of solid potassium chloride and diatomic oxygen gas.
Writing and Balancing Chemical Equations
Balancing Equations. A balanced chemical is equation has equal numbers of atoms for each element involved in the reaction are represented on the reactant and product sides. This is a requirement the equation must satisfy to be consistent with the law of conservation of matter. An equation is basically saying that two things (expressions, to be exact) are EQUAL. Since in a balanced situation the two sides of the balance hold equal weight, we can model simple equations with a balance. In the pictures below, each circle represents one and the block represents the unknown x. To find out what the block weighs, you can. Balancing chemical equations means that you write the chemical equation correctly so that there is the same amount of mass on each side of the arrow. In this section, we’re going to explain how to balance a chemical equation by using a real life example, the chemical equation that occurs when iron rusts: Fe + O 2 > Fe 2 O 3.
General Education. A chemical equation tells you what happens during a chemical reaction. A balanced chemical equation has the correct number of reactants and products to satisfy the Law of Conservation of Mass. On the left side of the equation are the reactants. These are the materials that you start with in a chemical reaction. On the right side of the equation are the products. The products are the substances that are made as a result of a chemical reaction.
Balancing chemical equations means that you write the chemical equation correctly so that there is the same amount of mass on each side of the arrow. The first step in balancing a chemical equation is to identify your reactants and your products.
Remember, your reactants are on the left side of your equation. The products are on the right side. For this equation, our reactants are Fe and O 2. Our products are Fe 2 and O 3. Next, you need to determine how many atoms of each element are present on each side of the equation.
You can do this by looking at the subscripts or the coefficients. If there is no subscript or coefficient present, then you just have one atom of something. Earlier, I mentioned that there are two ways to tell how many atoms of a particular element exist in a chemical equation: by looking at the subscripts and looking at the coefficients.
A coefficient is a whole number multiplier. To balance a chemical equation, you add these whole number multipliers coefficients to make sure that there are the same number of atoms on each side of the arrow. For instance, take the chemical equation for water: H2O. If you added a coefficient to make it 2H 2 O, then the coefficient multiples across all of the elements present. So, 2H 2 O means that you have four atoms of hydrogen and two atoms of oxygen. On the product side, we have two atoms of iron and three atoms of oxygen.
While that balances out the iron atoms leaving two on each side , oxygen is still unbalanced. That means we need to keep looking. That creates balance for iron by having four atoms on each side of the equation. Six is a multiple of two, so we can work with that on the reactant side, where two atoms of oxygen are present. Your main goal when balancing chemical equations is to make sure that there are the same amount of reactants and products on each side of the chemical equation arrow.
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How to Write an Amazing College Essay. A Comprehensive Guide. Choose Your Test. What Is a Chemical Equation? How to Balance Chemical Equations—Explanation and Example Balancing chemical equations means that you write the chemical equation correctly so that there is the same amount of mass on each side of the arrow.
That means we need to add coefficients to make this equation balanced. When you balance a chemical equation, you change coefficients. You never change subscripts. Have friends who also need help with test prep? Share this article! Hayley Milliman. About the Author. Search the Blog Search. Find Out How. Get the latest articles and test prep tips! Looking for Graduate School Test Prep?