August 17, 2021

MCQ of Chemical Reactions and Equations | Chapter 1 | Science, Class 10

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MCQ of Chemical Reactions and Equations | Chapter 1 | Science | Class X | CBSE |

MCQ of Chemical Reactions and Equations 

Question 1: Magnesium ribbon burns with dazzling white flame and converts into a white powder. The powder formed is known as 

  1. Magnesium chloride
  2. Magnesium oxide
  3. Magnesium bromide
  4. Information incomplete

Answer: B (Magnesium oxide )

Question 2: Which of the following observation helps in determining that whether a chemical reaction has taken place or not ?

  1. Change in shape 
  2. Change in state
  3. Change in temperature
  4. Both (B) and (C)

Answer: D (Both (B) and (C))

Question 3: Chemical equation can be made more concise and useful by using

  1. Atomic masses instead of words
  2. Chemical formulae instead of words
  3. Chemical words only
  4. None of these 

Answer: B ( Chemical formulae instead of words )

Question 4: The equation is referred as skeletal chemical equation for a reaction when

  1. The equation is unbalanced
  2. The equation is balanced
  3. The mass of is not same on both side of equation
  4. Both (A) and (C)

Answer: D (Both (A) and (C) ) 

Question 5: Which of the following statement refers to law of conservation of mass?

  1. In a chemical reaction mass can neither be created nor be destroyed
  2. Total mass of elements present in the product of chemical reaction is always equal to the total mass of elements present in the reactants of a chemical reaction
  3. There is no change in number of atoms of each element before and after a chemical reaction
  4. All of these

Answer: D ( All of these ) 

You may also read MCQ of Acids Bases and Salts, MCQ of Metals and Non Metals, MCQ of Light Reflection and Refraction, MCQ of Human Eye and Colourful World, MCQ of Life Processes for better understanding of the chapters.

Question 6 : Which of the following statement is not correct regarding the physical change? 

  1. Substance changes its physical appearance only
  2. There is no change in basic composition of a substance
  3. A new chemical substance is formed
  4. No formation of a new chemical substance takes place

Answer: C (A new chemical substance is formed)

Question 7: Which of the following is not an example of chemical change ?

  1. Digestion of food
  2. Ripening of fruits
  3. Sublimation of solid on heating
  4. Decomposition of potassium chlorate on heating to give oxygen

Answer: C ( Sublimation of solid on heating )

Question 8: Which of the following statement regarding a chemical reaction is not correct?

  1. The product formed have properties which are entirely different from those of the reactants
  2. Product of a chemical reaction are the new substance that obtained as a result of reaction
  3. New substances having properties and composition completely different from original substance
  4. None of these

Answer: D (None of these)

Question 9: In which of the following reaction; chemical reaction is indicated by change in colour?

  1. Reaction between colourless nitric oxide and oxygen
  2. Reaction between zinc and dilute hydrochloric acid
  3. Reaction between magnesium and air 
  4. None of these 

Answer: A ( Reaction between colourless nitric oxide and oxygen )

Question 10: Which of the following  information is not conveyed by a balanced chemical reaction ?

  1. Physical state of the reactants and products
  2. Reaction is feasible or not
  3. Number of atoms of each element of the reactant and product
  4. Symbols and formulae of all substance involved in the given reaction

Answer: B (Reaction is feasible or not)

Question 11: Which of the following method helps in making a chemical reaction more informative ?

  1. Physical state of reactant and product
  2. Reaction condition
  3. Concentration of reactant and product
  4. All of these 

Answer: D (All of these)

Question 12: On what chemical law is balancing of chemical reaction based on?

  1. Law of conservation of mass
  2. Law of conservation of energy
  3. Independent of any law
  4. None of these

Answer: A ( Law of conservation of mass )

Question 13: A reaction in which a single product is formed from two or more elements or compounds is known as 

  1. Displacement reaction
  2. Combination reaction
  3. Decomposition reaction
  4. Precipitation reaction

Answer: B (Combination reaction)

Question 14: Which of the following statement gives the correct information about decomposition reaction ?

  1. Reaction in which a single substance breaks up to give two or more simpler substance
  2. Reactions that are just opposite to combination reactions
  3. Reactions that can be carried out in presence of heat, light or electricity
  4. All of these

Answer: D (All of these)

Question 15: Name the reducing agent in the given reaction: 

Fe2O3 + 3CO → 2Fe + 3CO2

  1. Fe2O3
  2. CO
  3. Fe
  4. CO2

Answer: B (CO)

Question 16: The following reaction is an example of

NaOH + HCl → NaCl + H2O

  1. Displacement reaction
  2. Combination reaction
  3. Neutralisation reaction
  4. Precipitation reaction 

Answer: D (Precipitation reaction)

Question 17: The value of x and y respectively in the given reaction are 

MnO2 + xHCl → MnCl2 + yH2O + Cl2

  1. 4 and 2
  2. 2 and 2
  3. 2 and 4
  4. 4 and 4

Answer: A (4 and 2) 

Question 18: The food items cooked in oils and fats when left exposed for some time give unpleasant smell and taste. This phenomenon is called

  1. Corrosion
  2. Rancidity
  3. Galvanisation
  4. None of these

Answer: B (Rancidity) 

Question 19: The reaction in which anions and cations of two variable molecules switch places, forming two entirely dissimilar compounds is defined as 

  1. Displacement reaction
  2. Combination reaction
  3. Decomposition reaction
  4. Double displacement reaction 

Answer: D (Double displacement reaction) 

Question 20: When an iron nail is dipped in a solution of copper sulphate , the type of reaction observed is 

  1. Combination reaction
  2. Displacement reaction 
  3. Double displacement reaction
  4. Decomposition reaction

Answer: B (Displacement reaction) 

Question 21: Complete the following statement by choosing correct options for ‘X’ and ‘Y’. ”When iron and iron articles are exposed to atmosphere, they are attacked by oxygen and moisture of the air and a X coloured layer is formed on the surface. It is called Y.”

  1. X = Blackish, Y = rust
  2. X = brown , Y = Corrosion
  3. X = Reddish brown , Y = Rust
  4. Information incomplete

Answer: C (X = Reddish brown, Y = Rust)

Question 22: Which of the following is not an accurate method to prevent rancidity?

  1. By adding antioxidants
  2. By applying layer of oil or grease
  3. By Vacuum packing
  4. By replacing air with nitrogen

Answer: B (By applying layer of oil or grease)

Question 23: A solution of ‘X’ is used for whitewashing the walls. It reacts with ‘Y’ of air to form a thin layer of ‘Z’ on the walls. ‘Z’ is formed on the walls after two to three days of whitewashing and gives a shining white finish to the wall. Identify ‘X’ , ‘Y’ and ‘Z’ in the given statement.

  1. X = Calcium hydroxide, Y = Carbon dioxide, Z = Calcium carbonate
  2. X = Calcium hydroxide, Y = Oxygen, Z = Calcium carbonate
  3. X = Calcium carbonate, Y = Carbon dioxide, Z = Calcium hydroxide
  4. X = Quicklime, Y = Carbon dioxide, Z = Calcium carbonate

Answer: A ( X = Calcium hydroxide, Y = Carbon dioxide, Z = Calcium carbonate ) 

Question 24: Which of the following is an exothermic process?

  1. Decomposition of vegetable matter
  2. Sublimation of dry ice
  3. Respiration
  4. Both (A) and (C)

Answer: D (Both (A) and (C) ) 

Question 25: Which of the following is the accurate characteristic test for CO2 ?

  1. It burns in the presence of air with a pop sound
  2. When it is passed through lime water, it turns milky
  3. It turns moist litmus paper from blue to red
  4. Cannot be tested at all

Answer: B (When it is passed through lime water, it turns milky)

Question 26: Which of the following is the accurate characteristic test for H2?

  1. It burns in the presence of air with a pop sound
  2. When it is passed through lime water, it turns milky
  3. It turns moist litmus paper from blue to red
  4. Cannot be tested at all

Answer: A (It burns in presence of air with a pop sound) 

Question 27: Which of the following phenomenon is responsible for damage to car, bridges, iron railings, ships and to all the objects made up of metals?

  1. Rancidity
  2. Galvanisation
  3. Corrosion
  4. All of these

Answer: C (Corrosion) 

Question 28: Which of the following is not correct regarding a chemical equation?

  1. A chemical equation does not tell about the feasibility of a reaction
  2. Chemical equation of the reaction gives the actual idea about the rate of a reaction and how much time will be taken for the completion of reaction.
  3. If a substance is in the form of solution, the chemical equation does not provide any information about its concentration
  4. Chemical equation provides the names of various reactant and product of a chemical reaction

Answer: B ( Chemical equation of the reaction gives the actual idea about the rate of a reaction and how much time will be taken for the completion of reaction ) 

Question 29: The chemical reactions in which heat is evolved are called …… reactions and those in which heat is absorbed are called…… reactions.

  1. Exothermic and Endothermic respectively
  2. Endothermic and Exothermic respectively
  3. Photochemical and Combustion respectively
  4. None of these 

Answer: A ( Exothermic and Endothermic respectively ) 

Question 30: To prevent the packed food item from getting rancid, air is flushed from  the packets of food items and they are filled by 

  1. Hydrogen
  2. Oxygen
  3. Carbon dioxide
  4. Nitrogen

Answer: D (Nitrogen)

Question 31: Which of the following statement regarding the given reaction are correct ?

2H2S + SO2 → 3S + 2H2O

1.H2S is acting as reducing agent

2.H2S is acting as oxidising agent

3.SO2 acts as oxidising agent

4.SO2 undergoes reduction

  1. 1,2 and 3
  2. 1,2 and 4
  3. 1,3 and 4
  4. 1 and 4

Answer: C (1,3 and 4) 

Question 32: Ferrous sulphate FeSO4. 7H2O also called green vitriol upon heating first loses water molecules of crystallisation and a dirty white solid. Dirty white solid further decomposes to give brown coloured ferric oxide , sulphur trioxide and a pungent smelling gas. Identify the pungent smelling gas evolved.

  1. Oxygen
  2. Sulphur dioxide
  3. Ammonia
  4. Information incomplete

Answer: B (Sulphur dioxide) 

Question 33: Few statements are given regarding the reaction written below; Identify the incorrect one.

2AgBr → 2Ag + Br2 (in presence of sunlight)

  1. The above reaction is used in black and white photography
  2. Silver bromide is stored in dark coloured bottle to prevent it from getting decomposed
  3. The reaction shown is an example of Photochemical decomposition
  4. None of these 

Answer: D (None of these) 

Question 34: The generalised reaction shown is a

AB + CD → AD + CB

  1. Displacement reaction
  2. Decomposition reaction
  3. Double displacement reaction
  4. Neutralisation reaction  

Answer: C (Double displacement reaction) 

Question 35: When ammonium hydroxide solution is added to a solution of aluminium chloride, which of the following reaction occurs?

  1. AlCl3 + NH4OH → Al(OH) + NH4Cl
  2. AlCl3 + 3NH4OH → Al(OH)3 + 3NH4Cl
  3. AlCl3 + NH4OH → Al(OH)3 + NH4Cl
  4. All of these 

Answer: B ( AlCl3 + 3NH4OH → Al(OH)3 + 3NH4Cl )

Question 36: When nitric oxide and oxygen combine, a reddish brown coloured gas is formed. Name the gas.

  1. Nitrogen monoxide
  2. Sulphur dioxide
  3. Sulphur trioxide
  4. Nitrogen dioxide

Answer: D (Nitrogen dioxide) 

Question 37: While balancing a chemical reaction, the only numbers that are added or changed are

  1. Subscripts
  2. Superscripts
  3. Coefficients
  4. Molar masses

Answer: C (Coefficients) 

You may also go through other subjects like MCQs of Science, Social Science & English for Class 10 in order to have a strong hold on the subject with an intent to score higher in the first term examination. Do share the post if you liked it. For more updates and better understanding of the chapters, keep logging on BrainyLads

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