This set of Applied Chemistry Multiple Choice Questions & Answers (MCQs) focuses on “Saponification Value – 1”.
1. Saponification is the value of oil for which the number of mgs of KOH required to saponify the ________ present in the 1g of oil.
a) Fatty materials
c) Free acids
Explanation: The saponification is the value of oil determined as the number of mgs of KOH needed to saponify the fatty materials present in the 1g of oil. If it is free acids instead of fatty materials then it is called as neutralisation number.
2. It is __________ of fatty oils which leads to formation of soaps.
a) Alkaline hydrolysis
b) Alkaline electrolysis
Explanation: It is alkaline hydrolysis of fatty oils which leads to formation of soaps. As the fatty materials are present in the oil, that oil on saponification that means on alkaline hydrolysis gives the soaps as product.
3. Which of the following is not saponifiable?
a) Ground nut oils
b) Mineral oils
c) Castor oil
d) Coconut oil
Explanation: The castor oil, coconut oil and the ground nut oil are saponifiable. The mineral oils are not saponifiable. They are mixtures of hydrocarbons and do not react with KOH. So, they are not saponifiable.
4. ________ get large amount of alkali to hydrolysis.
a) Baby oil
b) Liquid paraffin
c) Vegetable oil
d) Liquid petroleum
Explanation: The vegetable oils and animal oils need large amount of alkali to hydrolysis. They are the mixture of glyceryl and esters of fatty acids. Baby oil, liquid paraffin and liquid petroleum are the mineral oils and they are not saponifiable.
5. The saponification value of the vegetable oil is _______
a) Very high
b) Very low
d) Cannot be determined
Explanation: The saponification of vegetable oil and animal oil is very high. They are very high because it is difficult to hydrolyse them and require more amount of alkali for hydrolysis.
6. The different properties of the soaps is due to the ___________
a) Nature of alkali
b) Nature of the oil
c) Temperature variance
d) Nature of the fats
Explanation: The nature of alkali decides the properties of the soap. The main characteristics of soap can be determined by nature of alkali used in the hydrolysis of the soap.
7. Hard soaps can be formed by using ______
Explanation: The hard soaps are formed by using the sodium hydroxide. The potassium hydroxide is used to produce soft soaps. Hard soaps can give the lather even with hard water.
8. The deformations caused in oil paintings are due to saponification.
Explanation: The visible deformations occur due to saponification. The ground layers of oil paint contain heavy pigments of metals like zinc white and they react with fatty acids and cause saponification.
9. Fatty acids have _____ inter molecular forces.
d) Very strong
Explanation: The fatty acids have low intermolecular forces as they are formed from glyceryl. They are responsible for the lowering of the melting point of soaps.
10. The mixtures derived from the diverse fatty acids are _________
b) Bi glycerides
Explanation: The mixtures derived from the diverse fatty acids are called as triglycerides. They are otherwise called as tri-esters. They can be converted into soaps very easily by one or two steps.
Sanfoundry Global Education & Learning Series – Applied Chemistry.
To practice all areas of Applied Chemistry, here is complete set of 1000+ Multiple Choice Questions and Answers.