What is condensation reaction? CBSE Class 9 Chemistry notes

How could water vapour contained in the air turn into liquid water? The answer to this question is ‘Condensation’. In CBSE Class 9 Chemistry, condensation appears in organic chemistry. It is nothing but a process in which a chemical reaction occurs while combining two or more molecules to form a single molecule. It usually happens within the loss of a small molecule, namely water. Therefore, it can be termed a dehydration synthesis if the water is lost.

In this article, let us discover some of the facts and information regarding the condensation process in general while understanding the other related concepts.

What is condensation?

In Class 9 Chemistry, condensation is explained by how vapours of water are converted into liquid. The main reason for this conversation is that there is a change in the substance’s temperature and pressure.

In detail, condensation is described as a chemical process that we tend to experience daily. For example, on a warm day, we can see that the mirror is fully covered with fog due to the temperature rise. Likewise, it is the same with taking a hot shower. Upon touching the mirror, we can notice that there will be small water beds on the mirror. This fog is because of condensation. Let us discuss it more in the upcoming passages.

Condensation – Explanation

It is a fact that the condensation point and boiling point are the same. The occurrence of condensation will be at 100 ℃. While doing so, water will evaporate right after the temperature rises from the boiling point. In this case, it can be beyond 100 ℃. The water will boil and evaporate into the air, then form the water vapour. 

Furthermore, if we reverse the process, i.e. when the water is cooled down to 10 ℃, the vapour will condense, turning back into its original liquid form. The condensation process occurs between the temperatures 0 ℃ and 100 ℃ or 32 ℉ and 212 ℉. 

One can notice it very well when there is a higher temperature difference between the atmosphere and the object. For instance, in ice candies, there will be a formation of droplets of water molecules when the temperature is hot.

Condensation in the water cycle

The CBSE Chemistry students should know how condensation works in a water cycle. One of the key parts of the water cycle is condensation. Condensation is capable of showing how water is being cycled continuously throughout the earth’s liquid, solid, and gaseous forms.

During the condensation process, water vapour will change into actual water in the form of fog, using moisture. Moreover, when there is a positive change in the altitude of the earth, there will be a decrease in the pressure and temperature of the earth, converting the vapours of water into liquid form.

In addition, a large amount of concentration of these water droplets will form fog and cumulus clouds. After that, one can see that the water droplets get condensed, followed by falling on the earth’s surface as precipitation. This precipitation is commonly referred to as rain.

Rain first enters the earth’s waterways, followed by entering the soil. After it gets into the soil, it will be absorbed by the plants, which will help them grow using photosynthesis. It is a process in which the plants absorb water, sunlight and carbon dioxide and emit oxygen. 

Moreover, the water entering the soil will freeze to form a solid form. This solid form is commonly called ice. After doing so, it is capable of melting back into the water. This water can be utilised in all forms.

Given below are the various forms of condensation:

• Rain
• Snow
• Icicles
• etc.

After that, there is another step that takes place. This step is named evapotranspiration. It is nothing but the conversion of water from liquid to gas. This process can be seen as the combination of evaporation from earth’s rivers, lakes, oceans, and transpiration from plants and trees. Evapotranspiration plays a crucial part in the earth’s surface because it can sustain life and help survive all living things.

Understanding chemical bonding of condensation

In chemical bonding, a condensation reaction occurs when there is a combination of two or more molecules to form a larger molecule. While doing so, there will be a simultaneous removal of a minute molecule, namely methanol or water. It happens in a lot of day-to-day reactions. It is also usually reserved for reactions where new carbon-carbon bonds are formed.

Organic Chemistry and Condensation 

In Class 9, two molecules combine to form a single one in organic chemistry. Here, water is usually eliminated during the condensation reaction because it is a small molecule. Moreover, amino acids are considered as the biological molecules that consist of a functional group of amine on the molecule’s one end. Meanwhile, there is a carboxylic acid functional group on the other end of the molecule.

In a normal condensation reaction, two amino acids will be combined. Due to that, there will be a formation of a covalent bond. It appears between the first amino acid’s amine nitrogen and the second amino acid’s carboxyl carbon.

Moreover, due to this combination, the water molecule will be formed, which is removed in the condensation process.

Esterification

The CBSE students should be aware of another important subdivision under the process of condensation, which is esterification. An esterification reaction can be considered a condensation reaction, from which the ester is formed from the alcohol’s product and a carboxylic acid.

Esterification is regarded as the subcategory of condensation reactions due to the production of a water molecule in the reaction. Furthermore, strong acids such as sulphuric acid are utilised as a catalyst in this reaction.

A heating process will occur between the butanoic acid and carboxylic acid, with the addition of methanol and a few drops of sulphuric acid in it. It will ultimately result in producing the ester methyl butanoate. Methyl butanoate is capable of producing the aroma in pineapples and many fruits alike.

Structure of Esterification reaction

Apart from all that, the CBSE Chemistry students should understand how the esterification reaction is structured. This reaction is considered a reversible one. The reaction occurs while heating an ester in the presence of a strong base, namely sodium hydroxide. While doing so, there will be a breakdown of ester. Its products will be a type of alcohol and a conjugate base as a carboxylic acid salt. The reaction is provided below:

CH3 COOCH2 CH3 ethyl ethanoate + NaOH → CH3 COO – Na + sodium acetate + CH3 CH2 OH Ethanol

In the specified reaction, sodium hydroxide does not act as a catalyst. It is because it has been consumed in the reaction.

Saponification

In Chemistry, saponification means the alkaline hydrolysis reaction of an ester. This term usually describes the long-chain esters’ hydrolysis, which is named fatty acid esters. It is capable of producing molecules of soap. Moreover, these are also described as the salts of the fatty acids.

In that, one of the soap molecules is sodium stearate. It is usually formed from the hydrolysis of ethyl stearate.

C17 H35 COOC2 H5 ethyl stearate + NaOH → C17 H35 COO- Na + sodium stearate soap + C2 H5 OH

Conclusion

In a nutshell, condensation is determined as the opposite process of evaporation. In this science-based article, the students have obtained the basic ideas of condensation and how it is being formed. There is a detailed explanation of what condensation is given. The Class 9 Chemistry students were able to understand the occurrence of condensation in the water cycle.

Moreover, an in-depth study of condensation in chemical bonding is also provided. A new topic called condensation in organic chemistry is also explained thoroughly. Concerning that, students obtained knowledge on esterification and the structure of esterification reactions. Ultimately, the CBSE Class 9 students can learn the process of saponification.

Preparing for CBSE Class 9? Here are some important pages that can help you.

NCERT Solutions

NCERT Solutions for Class 9

Important Concepts for Chemistry

FAQs

1. How does the condensation process take place in water?

Due to the temperature change, there will be an occurrence of a process called condensation. The air which is cooled will not be able to keep the water molecules separated. Therefore, they will go again so that they can form droplets.

The condensation reaction is one part of the water cycle. It is very much helpful in cycling the water continuously throughout the earth. It will mostly be in the form of solids, liquids or gases. Eventually, what happens inside the condensation process is that it will change the water vapour into actual water due to heat.

2. What is the meaning of monomer?

A molecule of any class of compounds, especially organic, is called a monomer. It is capable of reacting with other molecules, which could form a large number of molecules or polymers. Monomer’s essential feature is poly-functionality. It is nothing but the capacity of at least two monomer molecules to form chemical bonds.

In addition to that, bi-functional monomers can form only chainlike, linear polymers, whereas, on the other hand, high functionality monomers can yield polymeric network products that are cross-linked.

3. What is a condensation reaction called?

There is another name for condensation reaction, which is dehydration reaction. An additional product is being formed in this type of reaction. Along with that, it will also produce water in the presence of a catalyst or under basic or acidic conditions. There is a term for the opposite of condensation reaction. It is called a hydrolysis reaction.

4. What reaction is called an anabolic reaction?

Anabolism, also called biosynthesis, is nothing but a set of biochemical reactions. It is capable of constructing molecules from smaller compounds. In general, anabolic reactions are endergonic. It indicates that there will be a requirement for an energy input which could progress and are not spontaneous.

5. Can humans consume methanol?

No, consuming methanol could even cause death since it is an industrial chemical. Drinking 50 to 90 ml of methanol is very dangerous to our body without proper medical treatment. As it is an industrial chemical, it should never be consumed by us humans. It could have the same effects as consuming petrol, diesel, or any other industrial chemical. It is a health hazard if consumed.

6. Describe the acidity of rain.

Due to the presence of carbon dioxide in our atmosphere, we could expect a pH of about 5.6 from normal rain. It is slightly acidic since the value is less than 7. It could dissolve to form weak carbonic acid. Furthermore, it is the common value for normal rain. On the other hand, acid rain has a pH of about 4.2 to 4.4, which is dangerous to our skin.