1 CHAPTER Chemical Reactions and Equations
Multiple Choice
NIOS Class 10 Science & Technology Chapter 1 Solution
| Board | NIOS |
| Class | 10th (Secondary) |
| Subject | Science and Technology (212) |
| Topic | Question Answer, Solution, Notes |
Questions1.
Which of the following is not a physical change?
Answer -
(a) Boiling of water to give water vapour
(b) Melting of ice to give water
(c) Dissolution of salt in water
(d) Combustion of Liquefied Petroleum Gas (LPG)
2.The following reaction is an example of a4NH3(g) + 5O2(g) ✂ 4NO(g) + 6H2O(g)
Answer -
(i) displacement reaction
(ii) combination reaction
(iii) redox reaction
(iv) neutralisation reaction
(a)
(i) and (iv)
(b) (ii) and (iii)
(c) (i) and (iii) (d) (iii) and (iv)
3. Which of the following statements about the given reaction are correct?
Answer -
3Fe(s) + 4H2O(g) ✂ Fe3O4(s) + 4H2(g)(i) Iron metal is getting oxidised
(ii) Water is getting reduced
(iii) Water is acting as reducing agent
(iv) Water is acting as oxidising agent
(a) (i), (ii) and (iii) (b) (iii) and (iv)(c) (i), (ii) and (iv) (d) (ii) and (iv)
4. Which of the following are exothermic processes?
Answer -
(i) Reaction of water with quick lime
(ii) Dilution of an acid
(iii) Evaporation of water
(iv) Sublimation of camphor (crystals)
(a) (i) and (ii) (b) (ii) and (iii)(c) (i) and (iv) (d) (iii) and (iv)
Solid calcium oxide reacts vigorously with water to form calciumhydroxide accompanied by liberation of heat. This process iscalled slaking of lime. Calcium hydroxide dissolves in water toform its solution called lime water. Which among the following is(are) true about slaking of lime and the solution formed?
Answer -
(i) It is an endothermic reaction
(ii) It is an exothermic reaction
(iii) The pH of the resulting solution will be more than seven
(iv) The pH of the resulting solution will be less than seven
(a)
(i) And (ii)
(b)
(ii) and (iii)
(c)
(i) and (iv)
(d)
(iii) and (iv)
Barium chloride on reacting with ammonium sulphate formsbarium sulphate and ammonium chloride. Which of the followingcorrectly represents the type of the reaction involved?
Answer -
(i) Displacement reaction
(ii) Precipitation reaction
(iii) Combination reaction
(iv) Double displacement reaction
(a) (i) only (b) (ii) only(c) (iv) only (d) (ii) and (iv)
Electrolysis of water is a decomposition reaction. The mole ratio ofhydrogen and oxygen gases liberated during electrolysis of water is
Answer -
(a) 1:1
(b) 2:1
(c) 4:1
(d) 1:2
Which of the following is(are) an endothermic process(es)?
(i) Dilution of sulphuric acid
(ii) Sublimation of dry ice
(iii) Condensation of water vapours
(iv) Evaporation of water
(a) (i) and (iii) (b) (ii) only(c) (iii) only (d) (ii) and (iv)
In the double displacement reaction between aqueous potassiumiodide and aqueous lead nitrate, a yellow precipitate of lead iodideis formed. While performing the activity if lead nitrate is notavailable, which of the following can be used in place of leadnitrate?
Answer -
(a) Lead sulphate (insoluble)
(b) Lead acetate
(c) Ammonium nitrate
(d) Potassium sulphate
Short Answer Q uestions
19. Write the balanced chemical equations for the following reactionsand identify the type of reaction in each case.
(a) Nitrogen gas is treated with hydrogen gas in the presence of acatalyst at 773K to form ammonia gas.
(b) Sodium hydroxide solution is treated with acetic acid to formsodium acetate and water.
(c) Ethanol is warmed with ethanoic acid to form ethyl acetate inthe presence of concentrated H2SO4 .
(d) Ethene is burnt in the presence of oxygen to form carbondioxide, water and releases heat and light.20.
Write the balanced chemical equations for the following reactionsand identify the type of reaction in each case.
(a) Thermit reaction, iron
(III) oxide reacts with aluminium andgives molten iron and aluminium oxide.
(b) Magnesium ribbon is burnt in an atmosphere of nitrogen gasto form solid magnesium nitride.
(c) Chlorine gas is passed in an aqueous potassium iodidesolution to form potassium chloride solution and solid iodine.
(d) Ethanol is burnt in air to form carbon dioxide, water andreleases heat.
21. Complete the missing components/variables given as x and y inthe following reactions
(a) Pb(NO3)2 (aq) + 2KI(aq) ✄ PbI2 (x) + 2KNO3(y)
(b) Cu(s) + 2Ag NO3(aq) ✄ Cu(NO3)2(aq) + x(s)
(c) Zn(s) + H2SO4(aq) ✄ ZnSO4(x) + H2(y)
(d) CaCO3(s) ① ✁✁✁✂ CaO(s) + CO2(g)
22. Which among the following changes are exothermic orendothermic in nature?
(a) Decomposition of ferrous sulphate
(b) Dilution of sulphuric acid
(c) Dissolution of sodium hydroxide in water
(d) Dissolution of ammonium chloride in water23.
Identify the reducing agent in the following reactions
(a) 4NH3 + 5O2✄ 4NO + 6H2O(b) H2O + F2✄ HF + HOF(c) Fe2O3 + 3CO ✄ 2Fe + 3CO2(d) 2H2 + O2 ✄ 2H2O
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