Chemical Change

ChemistryPhysical and Chemical Changes


Chemical change is the process by which new forms of matter are formed. Combining baking soda and vinegar, is the experiment through which the changes and features of chemical reactions are noticeable.

This experiment also distinguishes physical change and chemical change clearly in a matter. The matter's properties are being understood by observing the chemical changes in them. Chemical changes can be observed in varied activities that are performed during daily life from the digestion of food to the explosion of fireworks, and the removal of grime by soap. A chemical change is a form of chemical reaction that results in an alteration in the arrangements of the atoms.

What are chemical changes?

Chemical changes can also be denoted as chemical reactions, which is the process by which 1 or more materials can be altered into various new materials. Chemical changes are also determined as the process where the atoms of the substances get rearranged. In matters, changes take place when matter absorbs or loses energy and this phenomenon is considered the changing states of matter (Ji et al. 2021).

Here the material absorbs energy, the molecules and atoms move faster and this enhances the kinetic energy. The kinetic energy pushes the particles far so that they can change their forms. This energy is determined as the thermal or heat energy through which the chemical changes take place.

In the state of matter the physical change is often reserved but the chemical change is not. There is a change in energy in the system during the occurrence of a chemical change. During the chemical change when heat energy is released it is determined as the exothermic reaction. On the other side, when the heat energy is absorbed during the reaction then it is denoted as the endothermic reaction. The major points that highlight the chemical change phenomena are mentioned below.

  • In chemical change the types and number of atoms will always remain constant but there will be alterations in their arrangements (Schwaller et al. 2019).

  • Chemical changes take place when 1 material is transformed into another material or other new products through a chemical reaction.

  • There are some chemical changes that are irreversible, like rusting of iron, cooking, mixing, heating, and baking.

Chemical change: Types

There are three major types of chemical reactions that can be found in everyday life as mentioned below.

Inorganic chemical change: The reaction that does not involve any carbon elements is determined as the inorganic chemical reaction. Examples: mixing bases and acids, redox reactions, and oxidation (Toscano et al. 2020).

Biochemical chemical change: The reaction that includes organic chemical changes takes place in living beings. This reaction can be controlled by hormones and enzymes. Examples: Krebs cycle, photosynthesis, fermentation, digestion, and nitrogen fixation.

Organic chemical change: The reaction that includes organic compounds like hydrogen and carbon is denoted as the organic chemical reaction. Examples: cracking of crude oil, halogenations, polymerization, and methylation.

Chemical changes: examples

Chemical changes can be observed through the following examples.

  • Burning of candle: This is denoted as the chemical change as during candle burning light, heat, water vapour, and ${CO_2}$ are released. Here the change is irreversible as the initial material can never be recovered again and loss and gain in energy can be observed.

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Figure 1: Rusting of iron

  • Rusting of iron: This is an oxidation reaction as here iron gets combined with ${O_2}$ in the air in presence of ${H_2O}$ to generate ${Fe_2O_3}$, which is the Hydrated iron (III) oxide that is called rust. After chemical change a new product is formed that can be denoted with the formula:

$${4Fe+3O_2+6H_2O\rightarrow 4Fe[OH]_3}$$

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Figure 2: Vinegar and baking soda: Chemical reaction

  • Vinegar and baking soda experiment: When vinegar ${(CH_3COOH)}$ gets mixed with baking soda ${(NaHCO_3)}$ a new product is formed. The mixture foams up with ${CO_2}$ gas. On using enough vinegar, the baking soda will react and will get disappeared into the vinegar (Primaryconnections, 2022). From this phenomenon, it can be stated that baking soda and vinegar react to form water ${(H_2O)}$, Carbon dioxide ${(CO_2)}$, and Sodium acetate ${(Na\:CH_3COO)}$.


The reaction that can never be reversed once it has been completed is called the chemical reaction. This reaction comprises of rearrangement of atoms of 1 or more than 1 material. The changes taking place in the chemical composition or properties of these materials are denoted as chemical reactions. Hence, it results in the formation of new products or products with different textures and colours. The process of combing 1 material with another includes the process of decomposition to produce new products, which can be referred to as the chemical reaction. Chemical change, is always accompanied by energy and mass, and during this process, the material either losses or gains its mass.


Q1. What happens when changes in energy and mass occur during chemical reactions?

In chemical change, the materials are accompanied by energy and mass, where they either gains or losses mass. The materials also gain or lose energy because of the breaking of bonds in reactants and the formation of new bonds in products.

Q2. How chemical reaction can be determined?

There are several characteristics of chemical changes as found in reactants and new products. Chemical reaction can be determined through temperature change, gas evolution, new materials formation, change in colours and texture, precipitate formation, and changes in states of matters.

Q3. What do you mean by chemical reaction?

Chemical reactions are often determined as chemical decomposition or synthesis where 1 material reacts with another to form one or more new materials. For example, chemical change can be seen in the burning of candles, rusting of irons, burning of coal or fuel, and so on.

Q4. What are the major types of chemical reactions?

In chemical change the atoms' types and numbers remain the same but they get rearranged. Following this phenomenon, there are three main types of chemical changes that can be seen: inorganic, biochemical, and organic chemical changes.



Ji, W., & Deng, S. (2021). Autonomous discovery of unknown reaction pathways from data by chemical reaction neural network. The Journal of Physical Chemistry A, 125(4), 1082-1092. Retrieved from:

Schwaller, P., Laino, T., Gaudin, T., Bolgar, P., Hunter, C. A., Bekas, C., & Lee, A. A. (2019). Molecular transformer: a model for uncertainty-calibrated chemical reaction prediction. ACS central science, 5(9), 1572-1583. Retrieved from:

Toscano, J., Lewandowski, H. J., & Heazlewood, B. R. (2020). Cold and controlled chemical reaction dynamics. Physical Chemistry Chemical Physics, 22(17), 9180-9194. Retrieved from:


Primary connections (2022). About Baking soda and vinegar experiment. Retrieved from: [Retrieved on: 27th June 2022]

Updated on 13-Oct-2022 11:19:47