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Which among of the following is not incorrect?
- a)A scale for measuring OH- concentration in a solution, called pH scale has been developed.
- b)As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.
- c)Tooth decay starts when the pH of the mouth is lower than 5.5.
- d)Stinging hair of nettle leaves inject a base which causes burning pain.
Correct answer is option 'C'. Can you explain this answer?
Verified Answer
Which among of the following is not incorrect?a)A scale for measuring ...
Ans: c
Explanation: A scale for measuring hydrogen ion concentration in a solution, called pH scale has been developed. The pH of a neutral solution is 7. Values less than 7 on the pH scale represent an acidic solution. As the pH value increases from 7 to 14, it represents an increase in OH– ion concentration in the solution, that is, increase in the strength of alkali.
Tooth decay starts when the pH of the mouth is lower than 5.5.
Bee-sting leaves an acid which causes pain and irritation. Stinging hair of nettle leaves inject methanoic acid causing burning pain.
Most Upvoted Answer
Which among of the following is not incorrect?a)A scale for measuring ...
Explanation:
Option C: Tooth decay starts when the pH of the mouth is lower than 5.5.
Tooth decay is a common dental problem that occurs when the enamel of the teeth is damaged by acids produced by bacteria in the mouth. These acids demineralize the enamel, leading to the formation of cavities. The pH scale is a measure of the acidity or alkalinity of a solution. It ranges from 0 to 14, with 7 being neutral, values below 7 being acidic, and values above 7 being alkaline or basic.
When the pH of the mouth drops below 5.5, it indicates an acidic environment. At this pH, the acid produced by bacteria can start to dissolve the minerals in the enamel, leading to tooth decay. Therefore, a lower pH indicates a higher acid concentration in the mouth, which increases the risk of tooth decay.
Option A: A scale for measuring OH- concentration in a solution, called pH scale has been developed.
The pH scale is commonly used to measure the acidity or alkalinity of a solution. It is based on the concentration of hydrogen ions (H+) in the solution. However, pH can also be used to indirectly measure the concentration of hydroxide ions (OH-) in a solution. The pH scale is logarithmic, meaning that each unit represents a tenfold difference in acidity or alkalinity.
Option B: As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.
This statement is incorrect. As the pH value increases from 7 to 14, it represents a decrease in acidity and an increase in alkalinity. In alkaline solutions, the concentration of hydroxide ions (OH-) is higher than the concentration of hydrogen ions (H+). Therefore, as the pH value increases, the concentration of hydroxide ions increases, indicating a stronger alkali.
Option D: Stinging hair of nettle leaves inject a base which causes burning pain.
This statement is correct. The stinging hairs of nettle leaves contain a chemical called formic acid. When the hairs come into contact with the skin, they break and release the formic acid, which acts as a base. The base causes a burning sensation and irritation on the skin, leading to the characteristic stinging pain.
In summary:
Option C is the incorrect statement because tooth decay starts when the pH of the mouth is lower than 5.5, not higher. The other options are correct: the pH scale measures OH- concentration (option A), increasing pH represents increasing alkalinity (option B), and nettle leaves inject a base causing burning pain (option D).
Option C: Tooth decay starts when the pH of the mouth is lower than 5.5.
Tooth decay is a common dental problem that occurs when the enamel of the teeth is damaged by acids produced by bacteria in the mouth. These acids demineralize the enamel, leading to the formation of cavities. The pH scale is a measure of the acidity or alkalinity of a solution. It ranges from 0 to 14, with 7 being neutral, values below 7 being acidic, and values above 7 being alkaline or basic.
When the pH of the mouth drops below 5.5, it indicates an acidic environment. At this pH, the acid produced by bacteria can start to dissolve the minerals in the enamel, leading to tooth decay. Therefore, a lower pH indicates a higher acid concentration in the mouth, which increases the risk of tooth decay.
Option A: A scale for measuring OH- concentration in a solution, called pH scale has been developed.
The pH scale is commonly used to measure the acidity or alkalinity of a solution. It is based on the concentration of hydrogen ions (H+) in the solution. However, pH can also be used to indirectly measure the concentration of hydroxide ions (OH-) in a solution. The pH scale is logarithmic, meaning that each unit represents a tenfold difference in acidity or alkalinity.
Option B: As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.
This statement is incorrect. As the pH value increases from 7 to 14, it represents a decrease in acidity and an increase in alkalinity. In alkaline solutions, the concentration of hydroxide ions (OH-) is higher than the concentration of hydrogen ions (H+). Therefore, as the pH value increases, the concentration of hydroxide ions increases, indicating a stronger alkali.
Option D: Stinging hair of nettle leaves inject a base which causes burning pain.
This statement is correct. The stinging hairs of nettle leaves contain a chemical called formic acid. When the hairs come into contact with the skin, they break and release the formic acid, which acts as a base. The base causes a burning sensation and irritation on the skin, leading to the characteristic stinging pain.
In summary:
Option C is the incorrect statement because tooth decay starts when the pH of the mouth is lower than 5.5, not higher. The other options are correct: the pH scale measures OH- concentration (option A), increasing pH represents increasing alkalinity (option B), and nettle leaves inject a base causing burning pain (option D).
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Which among of the following is not incorrect?a)A scale for measuring OH- concentration in a solution, called pH scale has been developed.b)As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.c)Tooth decay starts when the pH of the mouth is lower than 5.5.d)Stinging hair of nettle leaves inject a base which causes burning pain.Correct answer is option 'C'. Can you explain this answer?
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Which among of the following is not incorrect?a)A scale for measuring OH- concentration in a solution, called pH scale has been developed.b)As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.c)Tooth decay starts when the pH of the mouth is lower than 5.5.d)Stinging hair of nettle leaves inject a base which causes burning pain.Correct answer is option 'C'. Can you explain this answer? for UPSC 2025 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about Which among of the following is not incorrect?a)A scale for measuring OH- concentration in a solution, called pH scale has been developed.b)As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.c)Tooth decay starts when the pH of the mouth is lower than 5.5.d)Stinging hair of nettle leaves inject a base which causes burning pain.Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for UPSC 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which among of the following is not incorrect?a)A scale for measuring OH- concentration in a solution, called pH scale has been developed.b)As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.c)Tooth decay starts when the pH of the mouth is lower than 5.5.d)Stinging hair of nettle leaves inject a base which causes burning pain.Correct answer is option 'C'. Can you explain this answer?.
Which among of the following is not incorrect?a)A scale for measuring OH- concentration in a solution, called pH scale has been developed.b)As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.c)Tooth decay starts when the pH of the mouth is lower than 5.5.d)Stinging hair of nettle leaves inject a base which causes burning pain.Correct answer is option 'C'. Can you explain this answer? for UPSC 2025 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about Which among of the following is not incorrect?a)A scale for measuring OH- concentration in a solution, called pH scale has been developed.b)As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.c)Tooth decay starts when the pH of the mouth is lower than 5.5.d)Stinging hair of nettle leaves inject a base which causes burning pain.Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for UPSC 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which among of the following is not incorrect?a)A scale for measuring OH- concentration in a solution, called pH scale has been developed.b)As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.c)Tooth decay starts when the pH of the mouth is lower than 5.5.d)Stinging hair of nettle leaves inject a base which causes burning pain.Correct answer is option 'C'. Can you explain this answer?.
Solutions for Which among of the following is not incorrect?a)A scale for measuring OH- concentration in a solution, called pH scale has been developed.b)As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.c)Tooth decay starts when the pH of the mouth is lower than 5.5.d)Stinging hair of nettle leaves inject a base which causes burning pain.Correct answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for UPSC.
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Which among of the following is not incorrect?a)A scale for measuring OH- concentration in a solution, called pH scale has been developed.b)As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.c)Tooth decay starts when the pH of the mouth is lower than 5.5.d)Stinging hair of nettle leaves inject a base which causes burning pain.Correct answer is option 'C'. Can you explain this answer?, a detailed solution for Which among of the following is not incorrect?a)A scale for measuring OH- concentration in a solution, called pH scale has been developed.b)As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.c)Tooth decay starts when the pH of the mouth is lower than 5.5.d)Stinging hair of nettle leaves inject a base which causes burning pain.Correct answer is option 'C'. Can you explain this answer? has been provided alongside types of Which among of the following is not incorrect?a)A scale for measuring OH- concentration in a solution, called pH scale has been developed.b)As the pH value increases from 7 to 14, it represents an increase in OH- ion concentration in the solution, that is, decrease in the strength of alkali.c)Tooth decay starts when the pH of the mouth is lower than 5.5.d)Stinging hair of nettle leaves inject a base which causes burning pain.Correct answer is option 'C'. Can you explain this answer? theory, EduRev gives you an
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