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प्रश्न
What do you observe when :
an iron nail is kept in tap water for few days
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उत्तर
We observe reddish brown coating on the nail called rust (entirely new substance) is chemical change.
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संबंधित प्रश्न
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer
Which of the following is a reducing agent?
- oxygen
- chlorine
- hydrogen
- none of these
What are chemical reactions?
Explain the type of reactions on the basis of the direction of reaction.
Name the type of chemical reaction shown by the following equation:
CaCO3 → CaO + CO2
Name the type of chemical reaction shown by the following equation:
NaOH + HCl → NaCl + H2O
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Give an example of a reaction where the following are involved:
Close contact
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NaOH + HCl → NaCl + H2O
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HCl and Cl2
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Give a word equation for the following reaction.
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Complete the table given below.
| Addition of dil. H2SO4 to zinc | Test for gas evolved |
Give a balanced equation for a reaction involving the evolution of gas on the addition of dilute acid to sodium sulphite.
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Neutralization reaction and a precipitation reaction.
Which of the following is a chemical change?
Write the chemical reaction of baking soda with lemon.
How would you show that the settling of curd is a chemical change?
Why is spoiling food a chemical change?
