Common misconceptions › Class 7 › Science › Exploring Substances: Acidic, Basic and Neutral Class 7 Science · Chapter 2 · NCERT (gecu102)
Exploring Substances: Acidic, Basic and Neutral: common misconceptions
See the tempting mistake students make in Exploring Substances: Acidic, Basic and Neutral, why it feels right at first glance, and a worked visual example that shows the right idea.
Worked visual “If your child says…” (8) Teach & practice The tempting mistake & worked visual Does one unchanged litmus strip prove neutrality? Wrong
If blue litmus stays blue, the liquid must be neutral.
Why it feels right. I know how an acid changes blue litmus and assume every nonacid is neutral.
Right
Use both colours of litmus to distinguish acidic, basic and neutral samples in this test.
Worked example
Basic soap
Blue stays blue → Red turns blue
Neutral water
Blue stays blue → Red stays red
Blue litmus alone looks the same in both samples. Red litmus separates the cases. In a basic soap solution, blue litmus stays blue but red litmus turns blue. In a neutral water sample both strips keep their original colours. If your child says… (8 concept checks in this chapter)
As you work through Exploring Substances: Acidic, Basic and Neutral , listen for these everyday misunderstandings and use the prompt alongside each one.
If your child says…
“Every bitter food is basic.”
Ask together Does karela fit your rule? What’s true Karela is bitter but not basic. If your child says…
“Everything must be acidic or basic.”
Ask together Which group fits sugar when neither strip changes? What’s true Sugar solution is neither. If your child says…
“Vinegar will turn it green.”
Ask together Which cup shows the acidic sample’s colour? What’s true Vinegar is acidic, so expect a pink or red shade. If your child says…
“Yellow means it’s an acid.”
Ask together What colour would sugar solution leave? What’s true Neutral liquids also leave turmeric yellow. If your child says…
“Every indicator must change colour.”
Ask together Which sense could notice that change? What’s true A change in smell can provide the signal. If your child says…
“One drop makes it neutral.”
Ask together What would remain if there were too little base? What’s true Too little base leaves acid; excess base makes the mixture basic. If your child says…
“An acid needs another acid to cancel it.”
Ask together Did vinegar react with another acid here, or with a basic deposit? What’s true A suitable base reacts with excess acid. If your child says…
“Indian chemistry started with Ray.”
Ask together Could ancient chemistry begin with Ray? What’s true Ray’s histories describe chemistry before Ray’s lifetime. Use this chapter three ways Previous chapter The Ever-Evolving World of Science Next chapter Electricity: Circuits and their Components
In the app, your child answers a short check-in with confidence taps, and you see which of these misunderstandings showed up—and which ones are gone.
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