Types of Reactions
Project: Analyzing Chemical Reactions
Assignment Summary
In this assignment, you will predict the products of a chemical reaction and explain why you made this
prediction. You will use what you have learned about atoms, bonding, and the organization of the periodic
table in your explanation. You will then review and revise your prediction and explanation based on some
additional information.
Background Information
Atoms combine with other atoms to form chemical bonds. When atoms bond, electrons can be either
shared, donated, or gained. The likelihood that an atom of one element will bond with an atom of another
element is related to the number of valence electrons in each atom. For example, elements in Group 1A
contain one valence electron, and elements in Group 7A contain seven valence electrons. Elements from
these two groups are likely to bond with one another, as the one valence electron from the Group 1A
element can be donated to the Group 7A element to complete its outer valence shell.
In general, metals, which have only a few valence electrons, form ionic bonds with nonmetals that have
nearly full outer valence shells. In an ionic bond, one or more electrons are donated from the metal
element to the nonmetal element. Nonmetals tend to form covalent bonds with other nonmetals by
sharing one or more pairs of electrons.
There are several types of reactions that can occur between atoms and molecules. These include:
1. Combination reaction: This type of reaction occurs when two or more reactants combine to form a single product. For example, when sodium (Na) and chlorine (Cl) react, they form sodium chloride (NaCl).
2. Decomposition reaction: This type of reaction occurs when a single reactant breaks down into two or more products. For example, when water (H2O) is heated, it decomposes into hydrogen gas (H2) and oxygen gas (O2).
3. Displacement reaction: This type of reaction occurs when an element or ion is replaced by another element or ion in a compound. For example, when iron (Fe) reacts with copper sulfate (CuSO4), iron sulfate (FeSO4) is formed and copper (Cu) is displaced.
4. Redox reaction: This type of reaction involves the transfer of electrons between reactants. It can either be a reduction reaction (gain of electrons) or an oxidation reaction (loss of electrons). For example, the reaction between magnesium (Mg) and oxygen (O2) is a redox reaction, where magnesium is oxidized and oxygen is reduced to form magnesium oxide (MgO).
5. Acid-base reaction: This type of reaction involves the transfer of protons (H+) from an acid to a base. The resulting products are a salt and water. For example, when hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH), sodium chloride (NaCl) and water (H2O) are formed.
When predicting the products of a chemical reaction, it is important to consider the types of atoms involved and their valence electrons. Elements tend to bond with other elements in a way that allows them to have a full outer valence shell. This can be achieved through the transfer or sharing of electrons.
By understanding the periodic table and the number of valence electrons each element has, you can predict the types of bonds that are likely to form. Metals, which have few valence electrons, tend to form ionic bonds with nonmetals, which have nearly full outer valence shells. Nonmetals, on the other hand, tend to form covalent bonds with other nonmetals by sharing electrons.
Based on this knowledge, you can make predictions about the products of a chemical reaction. However, additional information such as reaction conditions and the specific properties of the reactants may be needed to make a more accurate prediction.