Question

1. What type of reaction is represented by the digestion of food in our body? 2. When ammonium hydroxide solution is added to aluminium chloride, a white ppt. of aluminium hydroxide is formed along with ammonium chloride solution. What type of chemical reaction is stated in the above chemical change. 3. What is thermite reaction? Mention its use. 4. In the refining of silver, the recovery of silver from silver nitrate solution involves displacement reaction with copper metal. Write down the chemical equation for the reaction. 5. What do you observe when a solution of lead nitrate and potassium iodide in water are mixed together. 6. A white substance X on exposure to sunlight turns grey. name the substance 'X' and the grey product 7. What would you observe when lead nitrate is heated? 8. When hydrogen gas is passed over a black substance 'X', the black coating turns brown due to (I) oxidation (ii) reduction. 9. Write a balanced chemical equation with symbols for the following reactions _ (i) Solutions of barium chloride and sodium sulphate in water react to give insoluble barium sulphate and the solution of sodium chloride. (ii) Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) to produce sodium chloride solution and water. 10. How can you say that respiration is an exothermic process? Name two biochemical reaction which are exothermic. 11.What happens when copper turnings are added to silver nitrate solution? 12. Why the solution of silver nitrate becomes blue in colour after some time when copper turnings are added to it 13. A solution of a substance 'X' is used for white washing _ (i) Name the substance 'X' and write the formula. (ii) Write the reaction of the above substance 'X' with water. 14. Why is the amount of gas double in one of the test tube during the electrolytic decomposition of water? Name the gas? 15. When a green iron salt is heated strongly, its colour finally changes to black and odour of burning sulphur is given out. (i) Name the iron salt (ii) Name the type of reaction that takes place during the heating of iron salt. (iii) Write the chemical equation for the reaction involved. 16. Write one equation each for decomposition reactions where energy is supplied by heat, light and electricity. 17. What is the difference between displacement and double displacement reactions? Write equations for these reactions. 18.Classify each of the following reactions as combination, decomposition, displacement or double displacement reaction. (i) H2 + Cl2 → 2HCl (ii) 2KClO3 2KCl + 3O2 (iii) Zn + CuSO4 → ZnSO4 + Cu Blue Colour less (iv) 2Pb(NO3)2 2PbO(s) + 4NO2(g) + O2(g) (v) NaOH + HCl → NaCl + H2O (vi) BaCl2 + H2SO4 → BaSO4 + 2HCl (vii) CaO + CO2 → CaCO3 (viii) CaCO3 CaO + CO2 (ix) 2KI + Cl2 → 2KCl + I2

Answer 1

1.Digestion of food is oxidation , exothermic , decomposition reaction.

2.Double displacement reaction.

3.Fe2O3 + 2Al--------->Al2O3 + 2Fe + HEAT.
This is thermit reaction. This is used for welding railway tracks.

4.Cu + Ag2S ----------> Cu2S + Ag.

5.

6.X is silver chloride. The grey product is silver.

7.Emission of brown fumes due to emission of NO2 gas.

8.Copper oxide is X and CuO is reduced and H2 is oxidised.
The equation is CuO + H2-------->Cu + H2O.


Feel free to message me if you have ay Doubts.

May this new year be happy and prosperous for you.

Please mark my answer as brainliest.

- Maheshwaran.