Video Transcript
The symbol equation for a chemical reaction is shown below. Two NaOH plus H2SO4 react to form Na2SO4 plus two H2O. What are the products of this reaction?
In this question, the provided symbol equation represents a specific chemical reaction. A chemical reaction is the process of chemical change. A symbol equation, which is also called a chemical equation, represents a chemical reaction using chemical symbols. Each chemical symbol gives the identity of a specific chemical element from the periodic table. For example, in the substance Na2SO4, the first chemical symbol is Na. Na represents the element sodium. The number two next to the symbol Na is called a subscript. It tells how many sodium atoms are present. This substance also contains sulfur, which is represented by the chemical symbol S, and oxygen, which is represented by the chemical symbol O. The number four that appears after the symbol O is a subscript indicating that one unit of Na2SO4 contains four oxygen atoms. When chemical symbols are written together with no spaces between them, they represent the chemical formula of a compound.
Altogether, a chemical equation contains three main parts. The first part shows the chemical formulas of the reactants and is located to the left of the reaction arrow. The reactants are the starting materials of a chemical reaction. If more than one substance is reacting, a plus sign is used to separate the two substances and can be thought of as the word “and.”
There are two reactants in the provided equation. The first reactant is the compound NaOH, which has the name sodium hydroxide. The second reactant has a chemical formula of H2SO4. The name of this substance is sulfuric acid. The two in front of the chemical formula for sodium hydroxide is a coefficient used to balance the chemical equation. It tells how many units or molecules of a substance are involved in a reaction.
In this reaction, two units of sodium hydroxide react with one unit of sulfuric acid. Sodium hydroxide is an ionic compound. When dissolved in sulfuric acid, the sodium and hydroxide ions separate from each other. On the other hand, sulfuric acid is a covalent compound. And the atoms in the sulfuric acid molecule are joined by covalent bonds.
Let’s return to our chemical equation. The second main part of a chemical equation is the reaction arrow. The reaction arrow can be represented by the words “react to produce.”
Finally, the third main part of a chemical equation shows the chemical formulas of the products. Products are the new substances made during the reaction and have different chemical compositions and properties when compared to the reactants. In this reaction, one unit of Na2SO4, or sodium sulfate, is produced per every two molecules of water that are produced. All of the elements that were present in the reactants are also present in the products. But the products contain new combinations of these elements.
Sodium sulfate is an ionic compound and is soluble in water. The sodium and sulfate ions remain separate from each other in the solution. On the other hand, water is a covalent compound. And the hydrogen and oxygen atoms are covalently bonded to each other in the water molecules. The products or new substances made in this reaction are sodium sulfate and water, or Na2SO4 plus two H2O.
