Practice focused topic-wise MCQs with answers and explanations for quick revision and exam preparation.
Difficulty select karke sirf is topic ke focused MCQs practice karein. Score, timer aur explanations student-friendly flow me milenge.
Showing 501-510 of 1900 questions.
What effect does an acidic solution have on blue litmus paper?
A. नीला लिटमस लाल हो जाता हैBlue litmus turns red
Litmus is used to identify acidic and basic solutions.
An acid turns blue litmus red.
Remember the opposite effect for bases in exams.
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What effect does a basic solution have on red litmus paper?
B. लाल लिटमस नीला हो जाता हैRed litmus turns blue
Bases behave differently from acids.
A basic solution turns red litmus blue.
Litmus colour change is a quick identification test.
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Why does a turmeric stain become reddish brown when soap is applied?
C. साबुन क्षारीय होता हैSoap is basic
Turmeric is a natural indicator.
It turns reddish brown in a basic medium.
Natural indicator colour changes are common exam questions.
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Which substance is applied to reduce the effect of acid present in an ant sting?
C. बेकिंग सोडा का विलयनBaking soda solution
An ant sting contains an acidic substance.
Baking soda is mildly basic, so it neutralises the acid.
Acid-base reaction is called neutralisation.
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Which gas is generally released when an acid reacts with a metal?
D. हाइड्रोजनHydrogen
Acids react with many reactive metals.
The products are a salt and hydrogen gas.
Hydrogen gives a pop sound near a burning splint.
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Which gas is released when an acid reacts with a metal carbonate?
B. कार्बन डाइऑक्साइडCarbon dioxide
Acids react with metal carbonates.
The products are salt, water, and carbon dioxide.
Carbon dioxide turns lime water milky.
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Why does lime water turn milky when carbon dioxide gas is passed through it?
A. कैल्शियम कार्बोनेट बनने के कारणDue to formation of calcium carbonate
Lime water is a solution of calcium hydroxide.
Carbon dioxide forms calcium carbonate, which appears milky.
This is an important test for carbon dioxide.
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What is the safe method for dissolving an acid in water?
B. अम्ल को धीरे-धीरे जल में डालना चाहिएAcid should be added slowly to water
Dissolving acid in water is an exothermic process.
Adding acid slowly to water reduces splashing risk.
Never add water directly to concentrated acid.
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Why do aqueous acids conduct electricity?
C. क्योंकि वे आयन बनाते हैंBecause they produce ions
Electric current needs charged particles to flow.
Acids produce ions in water, so they conduct electricity.
Dry acids generally do not show this behaviour.
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Which type of ions do bases produce in water?
B. हाइड्रॉक्साइड आयनHydroxide ions
The nature of a base is understood from the ions it forms in water.
Bases produce hydroxide ions in water.
Acids produce hydrogen ions, so keep the difference clear.
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