Why does a dry acidic gas not change dry litmus?
Answer and explanation
Correct answer: Ions do not form without water
The governing concept is that acidic behaviour in aqueous conditions depends on the formation of hydrogen ions, or hydronium ions, in water. A dry acidic gas has no water available to ionise it, and dry litmus cannot provide the aqueous medium needed for this ion formation. Therefore no colour change occurs and option A is correct. Litmus is an indicator, not a metal, and indicators do work when moisture is present.
Frequently asked questions
What is the correct answer to this question?
Ions do not form without water
Why is this the correct answer?
The governing concept is that acidic behaviour in aqueous conditions depends on the formation of hydrogen ions, or hydronium ions, in water. A dry acidic gas has no water available to ionise it, and dry litmus cannot provide the aqueous medium needed for this ion formation. Therefore no colour change occurs and option A is correct. Litmus is an indicator, not a metal, and indicators do work when moisture is present.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
