Why can it be wrong to decide whether a colourless solution is an acid or a base just by looking at it?
Answer and explanation
Correct answer: Many acids and bases can be colourless so indicators are needed
The governing concept is chemical identification using indicators rather than appearance. Many common acids and bases, such as dilute hydrochloric acid and sodium hydroxide solution, are colourless. Litmus, universal indicator, or pH paper undergoes a characteristic colour change that provides evidence about acidic or basic nature. Thus option A is correct; no fixed visible colour applies to every acid or base, and colour alone cannot give exact pH.
Frequently asked questions
What is the correct answer to this question?
Many acids and bases can be colourless so indicators are needed
Why is this the correct answer?
The governing concept is chemical identification using indicators rather than appearance. Many common acids and bases, such as dilute hydrochloric acid and sodium hydroxide solution, are colourless. Litmus, universal indicator, or pH paper undergoes a characteristic colour change that provides evidence about acidic or basic nature. Thus option A is correct; no fixed visible colour applies to every acid or base, and colour alone cannot give exact pH.
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.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
