Question 1:
What is soap?
Answer:
Soaps are sodium or potassium salts of fatty acids.
What is soap?
Answer:
Soaps are sodium or potassium salts of fatty acids.
Question 2:
What is detergent?
Answer:
Detergents are sodium or potassium salts of sulphonic acids.
What is detergent?
Answer:
Detergents are sodium or potassium salts of sulphonic acids.
Question 3:
Name the process of soap preparation.
Answer:
Saponification.
Name the process of soap preparation.
Answer:
Saponification.
Question 4:
Give a balanced chemical equation for the reaction between stearic acid and sodium hydroxide to prepare soap.
Answer:
$$ \mathrm{CH}_3\left(\mathrm{CH}_2\right)_{16} \mathrm{COOH}+\mathrm{NaOH} \rightarrow \mathrm{CH}_3\left(\mathrm{CH}_2\right)_{16} \mathrm{COONa}+\mathrm{H}_2 \mathrm{O} $$
Give a balanced chemical equation for the reaction between stearic acid and sodium hydroxide to prepare soap.
Answer:
$$ \mathrm{CH}_3\left(\mathrm{CH}_2\right)_{16} \mathrm{COOH}+\mathrm{NaOH} \rightarrow \mathrm{CH}_3\left(\mathrm{CH}_2\right)_{16} \mathrm{COONa}+\mathrm{H}_2 \mathrm{O} $$
Question 5:
State the two stages in the process of preparing detergents.
Answer:
Sulphonation or sulphation and neutralisation.
State the two stages in the process of preparing detergents.
Answer:
Sulphonation or sulphation and neutralisation.
Question 6:
One of the properties of soap or detergent is to form foam. What is the function of the foam?
Answer:
Soap bubbles will lower the surface tension of water surface in the following ways:
• Soap bubbles are a layer of spherical soap film that covers air or gas.
• The film consists of a thin layer of water trapped between two layers of soap molecules.
• The hydrophilic part of the soap molecule will dissolve in water, while the hydrophobic hydrocarbon chain part tends to avoid water.
• The hydrophobic ends of soap molecules accumulate on the surface, avoiding water and stays away from the water molecular layer.
• As a result, water molecules separate from each other. Increased distances between water molecules will cause a decrease in surface tension, which allows bubbles to form. Thus, soap can wet the surface of the fabric.
One of the properties of soap or detergent is to form foam. What is the function of the foam?
Answer:
Soap bubbles will lower the surface tension of water surface in the following ways:
• Soap bubbles are a layer of spherical soap film that covers air or gas.
• The film consists of a thin layer of water trapped between two layers of soap molecules.
• The hydrophilic part of the soap molecule will dissolve in water, while the hydrophobic hydrocarbon chain part tends to avoid water.
• The hydrophobic ends of soap molecules accumulate on the surface, avoiding water and stays away from the water molecular layer.
• As a result, water molecules separate from each other. Increased distances between water molecules will cause a decrease in surface tension, which allows bubbles to form. Thus, soap can wet the surface of the fabric.