These are always found to the left of the arrow in a chemical equation

Have you ever wondered what an arrow signifies in a chemical reaction? Why is there an arrow separating two different groups of chemicals like CH₄(g) + 2O₂(g)→CO₂(g) + 2H₂O(g)?

This is a chemical equation. The symbolic representation of a chemical change is a chemical equation. The reactants (the chemicals that initiate the chemical reaction) are represented on the left, while the products (the substances that result from the reaction) are represented on the right. An arrow sign ("→" commonly read aloud as "yields") separates the two.

The state attributes of products and reactants, either aqueous (dissolved in water — aq), solid (s), liquid (l), or gas, should be included in chemical equations.

USE OF ARROW IN CHEMICAL EQUATIONS

When a reaction necessitates energy use, it is frequently shown above the arrow. If energy is provided to the reaction in the form of heat, a capital Greek letter delta (Δ) is placed on top of the reaction arrow; if energy is supplied in the form of light, hv is inscribed.

There are a wide variety of reactions possible in our everyday lives: Elements can form compounds (as shown in the reaction), compounds can generate elements (water will split in the presence of a current flow to release hydrogen gas and oxygen gas), or compounds can mix, split away, or reorganize to form new compounds.

TYPES OF ARROWS IN A REACTION:

1. Right Arrow: The right arrow is the most prevalent arrow in a chemical reaction formula. The direction indicates the reaction's direction.

2. Double Arrow: A reversible reaction is indicated by the double arrow.

3. Equilibrium Arrow: When the reaction is at equilibrium, two arrows with solitary spikes directed in opposing directions suggest a reversible reaction.

4. Broken or Crossed Arrow: An arrow with a centered double hash or cross indicates that a response cannot occur. Broken arrows can also indicate reactions that were attempted but failed.

CONCLUSION:

• A chemical equation is an empirical representation of a chemical process.
• Base materials are represented on the left-hand side of the equation as reactants.
• The right-hand side of the equation contains the products, which are the reaction results.
• A chemical or physical transition is represented by the arrow.
• In chemical reaction formulae, the right arrow is by far the most prevalent arrow. The direction indicates the reaction's direction.

FAQs:

1. What is an arrow in a chemical equation?

Chemical equations are written in a standard format. The reactants are listed on the left side of the equation, while the products are listed on the right. The direction of the reaction is shown by an arrow pointing from the reactants to the products.

2. What does a crossed arrow mean in chemistry?

An arrow with a centered double hash or cross indicates that a response cannot occur. Broken arrows can also be used to indicate reactions that were attempted but failed.

We hope you enjoyed studying this lesson and learned something cool about What does an arrow mean in a chemical equation! Join our Discord community to get any questions you may have answered and to engage with other students just like you! Don't forget to download our App to experience our fun, VR classrooms - we promise, it makes studying much more fun! 😎

Continue your learning journey

Learn about the States of matter

Learn about the Structure of water

See hydrogen’s 3D model

SOURCES:

Chemical reaction formulas show the process of how one thing becomes another. Most often, this is written with the format:

Reactant → Products

Occasionally, you will see reaction formulas containing other types of arrows. This list shows the most common arrows and their meanings. 

This shows the simple right arrow for chemical reaction formulas. Todd Helmenstine

The right arrow is the most common arrow in chemical reaction formulas. The direction points in the direction of the reaction. In this image reactants (R) become products (P). If the arrow were reversed, the products would become reactants.

This shows the reversible reaction arrows. Todd Helmenstine

The double arrow denotes a reversible reaction. The reactants become products and the products can become reactants again using the same process.

These are the arrows used to denote a chemical reaction at equilibrium. Todd Helmenstine

Two arrows with single barbs pointing in opposite direction show a reversible reaction when the reaction is at equilibrium.

These arrows show strong preferences in an equilibrium reaction. Todd Helmenstine

These arrows are used to show an equilibrium reaction where the longer arrow points to the side the reaction strongly favors.

The top reaction shows the products are strongly favored over the reactants. The bottom reaction shows reactants are strongly favored over the products.

This arrow shows a resonance relationship between R and P. Todd Helmenstine

The single double arrow is used to show resonance between two molecules.

Typically, R will be a resonance isomer of P.

This arrow shows the path of a single electron in a reaction. Todd Helmenstine

The curved arrow with a single barb on the arrowhead denotes the path of an electron in a reaction. The electron moves from the tail to the head.

Curved arrows are usually shown at individual atoms in a skeletal structure to show where the electron is moved from to in the product molecule.

This arrow shows the path of an electron pair. Todd Helmenstine

The curved arrow with two barbs denotes the path of an electron pair in a reaction. The electron pair moves from the tail to the head.

As with the single barbed curved arrow, the double barb curved arrow is often shown to move an electron pair from a particular atom in a structure to its destination in a product molecule.

Remember: One barb - one electron. Two barbs - two electrons.

The dashed arrow shows unknown or theoretical reaction paths. Todd Helmenstine

The dashed arrow denotes unknown conditions or a theoretical reaction. R becomes P, but we don't know how. It is also used to ask the question: "How do we get from R to P?"

Broken arrows show a reaction that cannot occur. Todd Helmenstine

An arrow with either a centered double hash or cross shows a reaction cannot take place.

Broken arrows are also used to denote reactions that were tried, but did not work.