Chemical reaction and equation part 2

Chemical reaction and equation important questions part – 2

• Complete the following reactions balance them and classify.  (i) CaCO₃ on heat __________ (ii) Pb(NO₃)₂ on heat __________ (iii) AgCl on come in contact of sunlight __________ (iv) AgBr …sunlight (v) H₂O   Electrolysis  (vi) Zn + CuSO₄… (vii)Pb + CuCL₂ (viii) Pb (NO₃)₂ + KBr…. (ix) ZnO + C (x) MnO₂ + HCl……
• What is the colour of K₂CrO₄ (Potassium chromate)?
• What happens when a chemical reaction occurs?
• What happens when Hydrogen combines with Oxygen in the presence of an electric current?
• Why do gold and platinum not corrode in moist air?
• Give an example of a double displacement reaction.
• What happens when an aqueous solution of sodium sulphate reacts with an aqueous solution of barium chloride? State the physical conditions of reactants in which the reaction between them will not take place. Write the balanced chemical equation for the reaction and name the type of reaction. (Delhi 2010)
• When the powder of a common metal is heated in an open china dish, its colour turns black. However,when hydrogenis passed over the hot black substance so formed, it regains its original colour. Based on the above information answer the following questions;(i) what type of chemical reaction takes place in each of the two given steps? (ii) Name the metal initially taken in the powder form. Write balanced chemical equations for both reactions.   (AI 2010)
• A housewife wanted her house to be whitewashed. She bought 10 kg of quick lime from the market and added it to 30 litres of water. On adding quick lime to water she noticed that the water appeared to be boiling even when it was not being heated. Give reason for her observation. Write the corresponding chemical equation and name the product formed.   (CBSE Sample Paper 2009)
• When magnesium ribbon burns in air or oxygen a product is formed. State the type of chemical reaction and name the product formed in the reaction. Write balanced chemical equation of this reaction. ( AI 2009C)
• What is a redox reaction? When a magnesium ribbon burns in air with a dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why? (Foreign 2009)
• (a) What is the colour of ferrous sulphate crystals? How does this colour change after heating?  (b) Name the products formed on strongly heating ferrous sulphate crystals. What type of chemical reaction occurs in this change?  (Delhi 2009)
• What is an oxidation reaction? Give an example of oxidation reaction. Is oxidation an exothermic or an endothermic reaction?    (Delhi 2009)
• What is observed when a solution of potassium iodide is added to a solution of lead nitrate taken in a test tube?
• What is an oxidation reaction? Identify in the following reaction: (Delhi 2008) ZnO +C produce Zn + CO (i) the substance oxidised and (ii) the substance reduced.