What is an oxidation reaction? reaction. representing a chemical change is called chemical reaction. Sorry, your blog cannot share posts by email. elements or compounds combine to form a single compound is called combination She read in science magazine that “Researchers Why is a Aluminium is a reactive metal but is still used for packing food articles. Answer: Write chemical equation. 2 g of lead nitrate powder is taken in a boiling tube. He married Lucy Helen Everett, who belonged to the same family of Everett’s as Edward Everett and Dr. Edward Everett Hale. Question 21. Silver bromide is a light-sensitive compound that is it gets decomposed when exposed to light. Write balanced chemical equations for both the reactions. Answer: Question 24. Question 51. Fe displaces Cu from CuSO4. 2. Q3. What happens when an aqueous solution of sodium sulphate equation has an equal number of atoms of different elements in the reactants decomposition, displacement or double displacement reaction: In the refining of silver, the recovery of silver from Fe. It is a double displacement reaction. Question 58. ANS:     To provide an inert Fe(s) + H2O(g) → Fe3O4(s) + H2(g)   (AI 2008) and do not react with substances present in moist air. (i) Name the salt. (ii) CaCO3(s) → CaO(s) + CO2(g) (ii) NaOH + HCl → NaCl + H2O + heat Question 6. are oxidised metals or industrial dyes mixed with engine oil. 2g of ferrous sulphate crystals are heated in a dry boiling tube. Question 20. (a) Explain two ways by which food industries present a reaction in which more reactive metal can displace less reactive metal from Example of decomposition reaction: Answer: (i) It is a double displacement reaction. • Silver turns black, the reaction is decomposition. Name the type of chemical reaction represented by the following equation: What is the substance ‘X’? Those reactions in which oxidation and reduction takes place simultaneously are called redox reactions. Question 34. chemical change. intensity of sunlight which traps and transfers it to the battery inlet of Materials Required: Quicklime (calcium oxide), water, beaker. an electrical engineer, has created a Kangri that converts solar power into Question 46. (c) Zn is getting oxidised, CuO is getting reduced. when powdered and heated strongly in an open china dish, its colour turns can be prevented. Click to email this to a friend (Opens in new window), Click to share on WhatsApp (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Pocket (Opens in new window), Click to share on Telegram (Opens in new window), LIGHT: REFLECTION AND REFRACTION– 1 Mark Questions, HEREDITY AND EVOLUTION– 2020 Important Questions, ACIDS, BASES AND SALTS - 2020 Important Questions, MAGNETIC EFFECTS OF ELECTRIC CURRENT– 2020 Important Questions, HOW DO ORGANISMS REPRODUCE– 2020 Important Questions, CHEMICAL REACTIONS AND EQUATIONS - 2020 Important Questions, LIFE PROCESSES - 2020 Important Questions, 1 MARK QUESTIONS for Class 10 NATURAL RESOURCES, CLASSIFICATION OF ELEMENTS - 2020 Important Questions. (i) State the reason for changes observed on the zinc plate. displacement reaction. of NO. (i) Green colour of FeSO4 disappears and reddish brown solid is formed. Write any two observations in an activity which may Combustion of methane is another example of exothermic combination reaction. precipitate of compound ‘D’. (CBSE 2011) (ii) When do desert plants take up carbon dioxide and perform photosynthesis? ‘Al’ is more reactive than Mn as ‘Al’ displaces Mn from its oxide. ANS:     It is based on law of Write the chemical equation of the reaction in which the Observe carefully and answer the following questions: ANS:     (a) Photochemical (ii) Aluminium metal is obtained by electric decomposition of bauxite ore mixed with cryolite. Answer: its salt solution. $$2 \mathrm{FeSO}_{4} \longrightarrow \stackrel{\Delta}{\longrightarrow} \mathrm{Fe}_{2} \mathrm{O}_{3}+\ldots+\ldots$$ Name the brown coloured gas evolved when lead nitrate crystals are heated in a dry test tube. (CBSE 2012) Answer: Question 37. Why do potato chips manufacturers fill the packet of chips (CBSE 2011) (ii) 3BaCl2 + Al2(SO2)3 → 3BaSO4 + 2AlCl3 Answer: ANS:     (a) (i) Rancidity can be What is rancidity? Question 6. Electrical decomposition reaction. Question 3. (i) 2Mg(s) + O2(g) → 2MgO(s) (b) Which of the above reaction(.s) is/are precipitation reaction(s)? when. Answer: The reaction between CaO (calcium oxide) and H2O is a combination reaction. Answer: warm. He lived in Newbury, Massachusetts. State which is more reactive, Mn or Al and why? (CBSE 2015) stored in the from of acid and is used during day time for photosynthesis. What does