Humber Admissions Practice Test

What characterizes a formation reaction?

1. One compound breaks down into simpler substances

2. Two or more elements produce one compound

3. Two or more compounds react to form one compound

4. One element replaces another in a compound

The correct answer is: Two or more elements produce one compound

A formation reaction is characterized by the combination of two or more elements to produce a single compound. This type of reaction is fundamental in the creation of new substances and is often represented by the general equation where the reactants (elements) are combined under specific conditions to yield a product (the compound). In a formation reaction, the elements involved typically exist in their standard states and combine to form a compound. This process is essential in chemistry, as many compounds found in nature are formed through these reactions. The other options describe different types of chemical reactions but do not align with the definition of a formation reaction. For instance, a compound breaking down into simpler substances represents a decomposition reaction, while the combination of two or more compounds to form one compound reflects a combination reaction, and the replacement of one element in a compound by another defines a single displacement reaction. Each of these reactions has distinct characteristics that differentiate them from a formation reaction, which specifically involves the synthesis of a compound from its elemental components.