Chapter 1: Chemical Reaction

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Q1. What change in colour is observed when white silver chloride is left exposed to sunlight?

Q2 Give an example of a redox reaction.

Q3. Which of the following listed metals can displace zinc from its salt solution? Give reason for your answer with a chemical equation:
Copper, Lead, Magnesium, Silver

Q4. Giving an example list two information which make a chemical reaction more useful? [ CBSE Delhi 2015]

Q5. Why magnesium ribbon clean before burning?

Q6. Which Substance is used for white-washing and its mixture with water feel hot?

Q7. Why Copper powder become black on heating ?

Q8 What Is Redox Reaction? Identifying The Substance Oxidised And The Substance Reduced In The Following Reactions:
(i) 2PbO + C → Pb + Co₂
(ii) MnO₂ + 4HCL → MnCl₂ + H₂O + Cl₂. [CBSE 2012]

Q9.Classify The Following Chemical Reactions As Exothermic Or Endothermic:
(i) Water Is Added To Quick Lime.
(ii) Dilute Sulphuric Acid Is Added To Zinc Granules.
(iii)When Ammonium Chloride Is Dissolved In Water In A Test Tube It Becomes Cold.
(iv) The Decomposition Of Vegetable Matter Into Compost.
(v) Electrolysis Of Water.
(vi) Silver Chloride Turns Grey In The Presence Of Sunlight To Form Silver Metal. [CBSE 2017]

Q10. Decomposition Reaction Require Energy Either In The Form Of Heat Or Light Or Electricity For Breaking Down Down The Reactants. Write One Equation Each For Decomposition Reaction Where Energy Is Supplied In The Form Of Heat, Light And Electicity. [CBSE 2018]