
What change will you observe if you test soap with litmus paper (red and blue)?
Answer
500.4k+ views
Hint: Soaps are the potassium or sodium salts of fatty acids. Thus, we can say that they are salts of weak acid and strong base. Litmus paper shows red colour in pH range 0 to 7 and shows blue colour in pH range 7 to 14.
Complete step by step solution:
We will see the composition of soap and how litmus paper changes its colour upon the nature of the solution.
- We know that soaps are sodium or potassium salts of fatty acids. The fatty acids are not as strong acids as mineral acids. Thus, we can call them the salt of weak acid and strong base.
- We know that the salt of weak acid and strong base gives an alkaline solution when dissolved in water. Soaps give and upon its dissolution in water. Alkaline solution has the pH range from 7 to 14.
- Litmus paper has some dyes on the paper which are sensitive to the pH of the solution. It has its characteristic colour in different solutions. Litmus paper is available in two colours; red and blue.
- When we dip a red litmus paper in the solution of soap, it will change its colour from red to blue. It shows that the solution is alkaline in nature.
- When we dip a blue litmus paper in the solution of soap, then it remains blue in colour.
Note: Note that we must require aqueous medium in order to check the pH of the solution by litmus paper. If we put dry litmus paper on solid soap without any presence of water on it, the red litmus paper will remain red.
Complete step by step solution:
We will see the composition of soap and how litmus paper changes its colour upon the nature of the solution.
- We know that soaps are sodium or potassium salts of fatty acids. The fatty acids are not as strong acids as mineral acids. Thus, we can call them the salt of weak acid and strong base.
- We know that the salt of weak acid and strong base gives an alkaline solution when dissolved in water. Soaps give
- Litmus paper has some dyes on the paper which are sensitive to the pH of the solution. It has its characteristic colour in different solutions. Litmus paper is available in two colours; red and blue.
- When we dip a red litmus paper in the solution of soap, it will change its colour from red to blue. It shows that the solution is alkaline in nature.
- When we dip a blue litmus paper in the solution of soap, then it remains blue in colour.
Note: Note that we must require aqueous medium in order to check the pH of the solution by litmus paper. If we put dry litmus paper on solid soap without any presence of water on it, the red litmus paper will remain red.
Recently Updated Pages
Master Class 11 Business Studies: Engaging Questions & Answers for Success

Master Class 11 Economics: Engaging Questions & Answers for Success

Master Class 11 Accountancy: Engaging Questions & Answers for Success

Master Class 11 Computer Science: Engaging Questions & Answers for Success

Master Class 11 Maths: Engaging Questions & Answers for Success

Master Class 11 English: Engaging Questions & Answers for Success

Trending doubts
Which one is a true fish A Jellyfish B Starfish C Dogfish class 11 biology CBSE

Difference Between Prokaryotic Cells and Eukaryotic Cells

1 ton equals to A 100 kg B 1000 kg C 10 kg D 10000 class 11 physics CBSE

One Metric ton is equal to kg A 10000 B 1000 C 100 class 11 physics CBSE

1 Quintal is equal to a 110 kg b 10 kg c 100kg d 1000 class 11 physics CBSE

Net gain of ATP in glycolysis a 6 b 2 c 4 d 8 class 11 biology CBSE
