Science
(a) ‘A’ & ‘B’ are sodium salts of long-chain carboxylic acid and long chain Sulphonic acid respectively. Which one of A or B will you prefer as a cleansing agent while using underground water (hand pump water)? Give the reason for your answer.
(b) Elaborate on the process of cleansing action. Illustrate micelle with the help of labelled diagram.
(c) Write the chemical equation of the preparation of soap from an ester CH3COOCH3. What is the name of this process?
Organic Chemistry
1 Like
Answer
(a) ‘A’ is the sodium salt of a long-chain carboxylic acid, which means it is a soap, while ‘B’ is the sodium salt of a long-chain sulphonic acid, which is a synthetic detergent.
When underground water (hard water) is used, it contains calcium and magnesium ions and these ions react with soaps to form insoluble scum, which reduces the cleansing efficiency of soap.
However, detergents do not form scum with the ions present in hard water because the sulphonate group of the detergent does not react with calcium or magnesium ions.
Hence, ‘B’ (detergent) is preferred as a cleansing agent in underground (hard) water because it remains effective and forms more lather even in hard water.
(b) Cleansing action of soap :
- Soaps are molecules in which the two ends have differing properties, one is hydrophilic, that is, it dissolves in water, while the other end is hydrophobic, that is, it dissolves in hydrocarbons.
- The molecules of soap are sodium or potassium salts of long-chain carboxylic acids. The ionic end of soap dissolves in water while the carbon chain dissolves in oil. The soap molecules, thus form structures called micelles where one end of the molecules is towards the oil droplet while the ionic end faces outside. This forms an emulsion in water. The soap micelle thus helps in dissolving the dirt in water and we can wash our clothes clean.
(c) When an ester reacts with a strong base (NaOH), it forms a salt of carboxylic acid (soap) and an alcohol.
Chemical equation :
CH3COOCH3 + NaOH → CH3COONa + CH3OH
This process is called saponification.
Answered By
1 Like
Related Questions
(a) Explain why the deflection of the compass needle reduced as Mona moved away the compass needle from the current carrying wire.
(b) Mention one thing that could have changed in the circuit of the wire that could increase the deflection of the needle.
(c) Explain with reason how the direction of the magnetic field associated with the wire changes if the polarity of battery reversed.
(a) “Keerthi thinks that Substitution reaction occurs in saturated Hydrocarbons, on the contrary Krishi thinks, it occurs in unsaturated Hydrocarbons.” Justify with valid reasoning whose thinking is correct.
(b) “Methane and Propane and their Isomers are used as fuels” Comment. Draw the electron dot structure of the immediate lower homologue of Propane. Give any two characteristics of homologues of a given homologous series.
(c) A mixture of oxygen and ethyne is burnt for welding. Can you predict why a mixture of ethyne and air is not used?
The image below shows a banana plant which is growing with the help of suckers. These suckers are small plant stem outgrowths which can be separated from the main plant and planted separately and they will grow into a new plant subsequently.
(a) Give the name and type of reproduction that is shown in the image above.
(b) List two advantages the farmer will have on using the type of reproduction mentioned above.
(c) The above plant produces male flowers. Explain how this plant will be involved in the process of pollination.
(d) Why is the offspring of this banana plant not absolutely identical to its parent plant?
A banana plant is growing with the help of suckers. These suckers are small plant stem outgrowths which can be separated from the main plant and planted separately and they will grow into a new plant subsequently.
(a) Give the name and type of reproduction.
(b) List two advantages the farmer will have on using the type of reproduction mentioned above.
(c) The above plant produces only male flower. Explain how this plant will be involved in the process of pollination.
(d) Why is the offspring of this banana plant not absolutely identical to its parent plant?