Question

1. Write balanced chemical equation for the following statements:
a. NaOH solution is heated with zinc granules.
b. Excess of carbon dioxide is passed through lime water.
c. Dilute sulphuric acid is added to sodium carbonate.
d. Egg shell is dropped in hydrochloric acid.
e. Copper (II) oxide reacts with dilute hydrochloric acid. [CBSE 2016]

2. Identify the type of chemical reaction in the following statement and define each of them:
a. Digestion of food in our body.
b. Rusting of iron.
c. Heating of manganese dioxide with aluminium powder.
d. Blue colour of copper sulphate solution disappears when iron filings are added to it.
e. Dilute hydrochloric acid is added to sodium hydroxide solution to form sodium chloride and water. [CBSE 2016]

3. a. Why respiration is considered an exothermic reaction?
b. Define the terms oxidation and reduction,
c. Identify the substance that is oxidized and reduced.
CuO(s) + Zn(s) heat Cu(s) + ZnO(s) [CBSE 2011]

4. A green coloured hydrated metallic salt on heating loses water of crystallisation molecules and gives a gas with suffocating smell. Identify the salt and write the chemical equation for the reaction. [CBSE 2011]

5. An aqueous solution of metal nitrate ‘P’ reacts with sodium bromide solution to form yellow precipitate ‘Q’ which is used in photography. ‘Q’ on exposure to sunlight undergoes decomposition to form metal present along with a reddish brown gas. Identify ‘P’ and ‘Q’ write the balanced chemical equation for the chemical reaction. List the two categories in which reaction can be placed. [CBSE 2012]

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Answer 1

Answer:

naoh + zn = na + znoh2 2 co2 +