What is a Reactant?
The substances which participate in a chemical reaction, are called reactants.
A chemical reaction describes the process by which atoms, the fundamental building blocks of matter, rearrange themselves to form new combinations. Reactants are raw materials that react with one another. The chemical bonds of the reactants are broken under the right conditions, such as temperature, time, or pressure, and the atoms form new bonds that result in different combinations. When writing down chemical reactions, the reactants are written on the left side, similar to a maths equation; one reactant plus another. To indicate that a reaction has occurred, an arrow is written to the right of the reactants, and the products are then written on the right side.
Table of Contents
- Examples of Reactants
- Identifying Reactants and products in Chemical Equations
- Reactant vs Reagent
- Reactant vs Catalyst
- Reactants vs Product
- Reactant vs Substrate
- Frequently Asked Questions – FAQs
Examples of Reactants
There are numerous possible reactions- Compounds can form elements, elements can form compounds, or compounds can combine, break apart, or rearrange to form new materials. The atoms are rearranged during a chemical reaction; they become detached and reattached to one another in various ways, resulting in different chemicals with different properties.
Every chemical reaction is usually expressed as-
Reactants → Products
A reaction can have multiple reactants.
- The equation can be used to determine a general reaction:
A + B → C
In this example, A and B are the reactants, and C is the product.
Such a reaction in which two or more than two reactants combine to form a single product is called a Combination reaction.
- In another reaction, for example:
C → A + B
The reactant is C, and the products are A and B.
Such a reaction in which a single reactant decomposes into its constituents elements or compounds is called a Decomposition reaction.
Read more: Types of Chemical Reaction
Identifying Reactants and Products in Chemical Equations
- To identify the reactants and products in a chemical equation, look at the reaction arrow. The arrow points from left to right in a reaction that only proceeds forward.
A + B → C
OR
C → A + B
The reactants are on the left side of the arrow, while the products are on the right.
- Many reactions proceed in both directions in order to achieve equilibrium. The reaction arrow only identifies the reactants and products, but this time the arrow points both ways!
A + B ⇔ C + D
The chemical species on each side of the reaction are both reactants and products in this type of reaction.
Reactant vs Reagent
The terms “reactant” and “reagent” are often used interchangeably. However, technically, the two words are quite different.
- A reagent is a substance that is added to cause a chemical reaction or to test whether one has occurred in analytical chemistry, whereas reactants are the starting material used in a chemical reaction to produce one or more products.
- Reagents are not always consumed in a reaction but reactants are completely used during the reaction.
Read more: Reagent
Reactant vs Catalyst
Catalysts are chemical compounds that speed up a reaction by lowering the activation energy needed to reach the transition state. A catalyst, unlike reactants, is not consumed during the reaction process.
Reactants vs Products
A chemical reaction’s two main components are reactants and products. Reactants are substances that initiate a chemical reaction. The chemical species that can be found after the reaction has been completed are referred to as products. The main difference between reactants and products is that reactants are consumed during the reaction, whereas products are formed as a result of the reaction.
Reactants vs Substrate
A substrate is a molecule that an enzyme acts on. The reaction alters the substrate, yielding two products.
A reactant and a substrate have the same meaning. In chemistry, the term reactant is more commonly used.
Read more: Substrate
Frequently Asked Questions on Reactants
Define reactants.
A chemical equation is an expression that describes a chemical reaction. Reactants are the starting materials, and they are written on the left side of the equation.
How do you find reactants and products?
Ans. The position of the reactants and products of a chemical reaction relative to the chemical reaction arrow can be used to identify them:
- Reactants are always written on the left side of the arrow
- Products are always written on the right side of the arrow
What type of reactions have only one reactant?
Decomposition reactions are reactions that constitute only one reactant. It is a reaction in which a single reactant decomposes into its constituent elements or compounds.
What is the limiting reactant?
A reactant in a chemical reaction has the ability to limit the amount of products produced by the reaction. When this occurs, the reactant is referred to as the limiting reactant (or limiting reagent). The theoretical yield is the amount of a product formed when the limiting reactant is completely consumed in a reaction.
How do reactants turn into products?
Reactants are raw materials that react with one another and form products. The chemical bonds of the reactants are broken under the right conditions, such as temperature, time, or pressure, and the atoms form new bonds that result in different combinations.
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