Question 1. Name any two industries based on forest resources.
Answer – (i) Industrialists use tendu leaves to make beedis.
(ii) There is a paper industry based on forest resources which is used on a large scale.
Question 2. Identify the substances being oxidized and reduced in the following reactions.
(i) 4Na(s)+O₂→ 2Na₂O(s)
(ii) CuO(s)+H2(g) → Cu(s)+H₂O(aq)
Answer – (i) Na is oxidized and oxygen is reduced.
(ii) Copper oxide is reduced but hydrogen is oxidized.
Question 3. What do you understand by precipitation reaction? Explain with example.
Answer: Precipitation reaction- A chemical reaction in which the products get separated from the solution as a solid substance is called precipitation. Sodium chloride (NaCl) and silver nitrate (AgNO3) are soluble in water. By mixing their solutions silver chloride (AgCl) is formed. It is insoluble in water. Therefore, it separates from the solution as a precipitate.
NaCl(aq) + AgNO (Aq) → AgCl(s)↓+NaNO(white precipitate)
Question 4. What is single displacement reaction?
Answer: A chemical reaction in which an element present in a compound is replaced by another element is called single replacement or single displacement reaction.
For example:- Zn metal displaces hydrogen from acid.
Zn+HCl → ZnCl2 + H₂
Question 5.What is single displacement reaction?
Answer: A chemical reaction in which an element present in a compound is replaced by another element is called single replacement or single displacement reaction.
For example:- Zn metal displaces hydrogen from acid.
Zn+HCl→ ZnCl2 + H₂
Question 6. Which gas is filled in the bag of chips and why?
Answer: The bag of chips is filled with N2 gas. Chips from this In the presence of oxygen it is protected from getting oxidized and it does not get deformed. If N₂ gas protects the chips from getting oxidized, that is why this gas is filled in the bag of chips.
Question 7. What is the difference between calcination and corrosion?
Answer -The process of rapidly heating the ore in a controlled supply of air at a temperature lower than its melting point is called corrosion. But The process of heating ore at a temperature lower than its melting point, due to which volatile impurities are thrown out and oxygen salts are transformed into oxides, is called calcination.
Question 8. What is bleaching powder? Write its chemical name formula and use.
Answer: Bleaching powder is formed by flowing chlorine gas on dry slaked lime. Its chemical name is calcium oxychloride. Its formula is Ca(OCl)Cl.
