Explicitly representing all dissolved ions results in a complete ionic equation. Ionic compounds dissolved in water are, therefore, more realistically represented as dissociated ions, in this case: Common abbreviations include s for solids, l for liquids, g for gases, and aq for substances dissolved in water aqueous solutions, as introduced in the preceding chapter.
Equations for Ionic Reactions Given the abundance of water on earth, it stands to reason that a great many chemical reactions take place in aqueous media. Solution Begin by identifying formulas for the reactants and products and arranging them properly in chemical equation form: 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.
To illustrate this, consider a reaction between ionic compounds taking place in an aqueous solution. For example, consider the reaction of ethane C2H6 with oxygen to yield H2O and CO2, represented by the unbalanced equation: When ionic compounds dissolve in water, they may dissociate into their 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.
Write balanced molecular, complete ionic, and net ionic equations for this process. In this particular case, the formulas for the dissolved ionic compounds are replaced by formulas for their dissociated ions: Dividing each coefficient by the greatest common factor, 3, gives the preferred equation: Additional Information in Chemical Equations The physical states of reactants and products in chemical equations very often are indicated with a parenthetical abbreviation following the formulas.
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.
These notations are illustrated in the example equation here: Balance oxygen last, since it is present in more than one molecule on the right side of the equation. When ions are involved in these reactions, the chemical equations may be written with various levels of detail appropriate to their intended use.
These spectator ions—ions whose presence is required 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:Worksheet: Writing and Balancing Chemical Reactions 1.
Balance the following equations and indicate the type of reaction as formation, decomposition, single. 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. Balancing Equations. When a chemical equation is balanced it means that 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.
Balancing Equations. The chemical equation described in section is balanced, meaning that 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. Writing and.
A chemical equation shows the chemical formulas of substances that are reacting and the substances that are produced. Balanced Chemical Equation: Writing and Balancing Combustion Reactions.Download