Bissoy.com
Doctors Medicines MCQs Q&A

Which of the following statements is/are correct? 1. Soaps used for cleaning purposes are sodium or potassium salts of long-chain fatty acids, e.g., stearic, oleic and palmitic acids. 2. Soaps do not work in hard water as it contains calcium and sulphate ions. Select the correct answer using the code given below.

Which of the following statements is/are correct? 1. Soaps used for cleaning purposes are sodium or potassium salts of long-chain fatty acids, e.g., stearic, oleic and palmitic acids. 2. Soaps do not work in hard water as it contains calcium and sulphate ions. Select the correct answer using the code given below. Correct Answer 1 only

The correct answer is 1 only.

Key Points

  • Soaps used for cleaning purposes are sodium or potassium salts of long-chain fatty acids, e.g. stearic, oleic, and palmitic acids. Hence, Statement 1 is correct.
  • Soaps containing sodium salts are formed by heating fat (i.e. glyceryl ester of fatty acid) with an aqueous sodium hydroxide solution. This reaction is known as saponification. 
  • In this reaction, esters of fatty acids are hydrolyzed and the soap obtained remains in colloidal form.
  • It is precipitated from the solution by adding sodium chloride. The solution left after removing the soap contains glycerol, which can be recovered by fractional distillation.
  • Only sodium and potassium soaps are soluble in water and are used for cleaning purposes.
  • Generally, potassium soaps are soft on the skin than sodium soaps. These can be prepared by using a potassium hydroxide solution in place of sodium hydroxide. 
  • Hard water contains calcium and magnesium ions. Hence, Statement 2 is incorrect.
    • These ions form insoluble calcium and magnesium soaps respectively when sodium or potassium soaps are dissolved in hard water. 

Related Questions

Consider the following statements.
1. Hard soaps (common bar soaps) are the sodium salts of fatty acids.
2. Soft soaps are the potassium salts of fatty acids and semi-solid in nature.
Which of the statement(s) given above is/are correct?
Which of the following statement(s) is/are correct?
1. If sodium carbonate and washing soda is mixed in water the hardness of water can be removed.
2. The reaction of the chemicals produce sodium sulphate, sodium carbonate and insoluble calcium carbonate.
3. Magnesium sulphate chloride and magnesium carbonate is also produced.
Select the correct answer
In the following question below are given three statements followed by three conclusions. Taking the given statements to be true even if they seem to be at variance from commonly known facts, read all the conclusions and then decide which of the given conclusion logically follows the given statements. Statements: Only salts are chili. Some sugars are salts. Only 60% sugars are turmeric. Conclusions: I. Some salts are chilies. II. Some chilies are salts. III. All sugars can be turmeric.
Consider the following statements: i) Fatty acids should be a part of the human diet. ii) Normal diet should contain 75 gm of fat. iii) The cells of the human body can not synthesize any fatty acids. iv) Deficiency disease develops due to the absence of essential fatty acids. Which of the above statements are correct?
Given below are two statements and four conclusions drawn based on the statements. Statement 1: Some soaps are clean. Statement 2: All clean objects are wet. Conclusion I: Some clean objects are soaps. Conclusion II: No clean object is a soap. Conclusion III: Some wet objects are soaps. Conclusion IV: All wet objects are soaps. Which one of the following options can be logically inferred?
Consider the following statements.
1. Among the fertilisers used, urea contains maximum percentage of Nitrogen.
2. The mixture of calcium sulphate is known as super phosphate of lime.
3. Potassium magnesium sulphate is called the muriate of potash.
Which of the statements given above are correct?
Measurement of KLa in a bioreactor can be carried out by sodium sulfite oxidation method, that is, based on the oxidation of sodium sulfite to sodium sulfate in the presence of a catalyst (Cu++ or Co++). In a typical experiment, a laboratory fermenter was filled with 5 liter of 0.5 M sodium sulfite solution containing 0.003 M Cu++ ions and the air was sparged in. After 10 min, the air flow was stopped and a 10 mL sample was taken and titrated. The concentration of sodium sulfite in the sample was found to be 0.20 M. The oxygen uptake rate for this aerated system will work out to be
In the following question below are given some statements followed by some conclusions. Taking the given statements to be true even if they seem to be at variance from commonly known facts, read all the conclusions and then decide which of the given conclusion logically follows the given statements. Statements: Some roses are pens. All pens are soaps.  Some soaps are bells. Conclusions: I. Some bells are pens. II. Some soaps are roses.
The bar graph given below shows the production of soaps (in thousands) by two companies P and Q from June to October. Which of the following statement(s) is/are correct? I. Total number of soaps produced by P in July is 28.5 percent more than Q in that month. II. Total number of soaps produced by P in August is 18.5 percent more than Q in that month. III. Total number of soaps produces by P and Q in September is 144000.
In this question, a statement is given followed by four conclusions. Choose the conclusion(s) which best fit(s) logically. Statement: To pass the examination, one must work hard. Conclusions: I. Examination is related to only hard work. II. All those who do not work hard pass. III. Without hard work, one does not pass. IV. Hard-working person is a satisfied person.