Explore topic-wise MCQs in 7th Class.

This section includes 2637 Mcqs, each offering curated multiple-choice questions to sharpen your 7th Class knowledge and support exam preparation. Choose a topic below to get started.

651.

DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 1 A change in which two or more substances (reactants) combine to produce one or more new substances (products) that has/have different chemical properties than the reactants is called chemical change. In a chemical change new products are formed. The characteristics of a chemical change are following: 1. Heat, light or any other radiation (ultraviolet) may be given off or absorbed. 2. Sound may be produced. 3. A change in smell may take place or a new smell may be given off. 4. A colour change may take place. 5. A gas may be formed. Change in which only physical properties of any substances get changed and no new substance is formed is called a physical change. Such as shape, size, colour and state, is known as physical change. A physical change is mostly reversible and during physical change no new substances are formed. Which of the following statements is not correct?

A. In a chemical change, colour of the object may change.
B. In a chemical change, heat will always be released.
C. A chemical change always involves physical change.
D. Rusting of iron becomes faster when humidity is high.
Answer» C. A chemical change always involves physical change.
Discussion
652.

Change of milk to curd is a:

A. physical change
B. chemical change
C. Both physical and chemical change
D. Neither physical nor chemical change
Answer» C. Both physical and chemical change
Discussion
653.

Match column I with column II and select the correct option from the codes given below.Column IColumn II(P) Dipping iron sheets in molten zinc(i) Alloying(Q) Prevents the iron surface to come in contact with moisture(ii) Galvanization(R) Two or more metals are mixed in definite ratio to form a homogeneous mixture(iii) Tinning(S) Coating expensive utensils with tin(iv) Painting           

A.  (P)-(iv),(Q)-(i), (R)-(ii),(S)-(iii)
B.  (P)-(iii),(Q)-(i),  (R)-(ii),(S)-(iv)
C.  (P)-(ii),  (Q)-(iv),(R)-(i),(S)-(iii)
D.  (P)-(i),  (Q)-(iii),(R)-(ii),(S)-(iv)
Answer» D.  (P)-(i),  (Q)-(iii),(R)-(ii),(S)-(iv)
Discussion
654.

Pooja took a candle in a vessel and heated the vessel. Even though the candle did not burn, it changed its shape and state. What kind of change is this?

A.  Neutralization
B.  Physical change
C.  Chemical change
D.  Irreversible change
Answer» C.  Chemical change
Discussion
655.

DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 1 A change in which two or more substances (reactants) combine to produce one or more new substances (products) that has/have different chemical properties than the reactants is called chemical change. In a chemical change new products are formed. The characteristics of a chemical change are following: 1. Heat, light or any other radiation (ultraviolet) may be given off or absorbed. 2. Sound may be produced. 3. A change in smell may take place or a new smell may be given off. 4. A colour change may take place. 5. A gas may be formed. Change in which only physical properties of any substances get changed and no new substance is formed is called a physical change. Such as shape, size, colour and state, is known as physical change. A physical change is mostly reversible and during physical change no new substances are formed. When we add sugar to water, it becomes sweet. Which of the following statements is TRUE regarding this change?

A. It is a chemical change because a new substance is formed
B. It is a chemical change because there is exchange of heat.
C. It is a physical change because the original substance can be recovered.
D. It is a chemical change because there is only change in colour.
Answer» D. It is a chemical change because there is only change in colour.
Discussion
656.

Directions: Match Column-I with Column-II and select the correct answer using the codes given below the columns. Column - I Column - II (A) The metal deposited on iron nails when they are dipped in the solution of copper sulphate. (p) Rusting (B) The substance/crust which gets deposited on an iron pan when left in moist air. (q) Copper (C) The process which converts iron to iron oxide in the presence of moisture and air. (r) Galvanization (D) Coating an iron sheet with a layer of zinc. (s) Rust

A. (A) \[\to \] (q), (B) \[\to \] (s), (C) \[\to \] (p), (D) \[\to \] (r)
B. (A) \[\to \] (r), (B) \[\to \] (s), (C) \[\to \] (p), (D) \[\to \] (q)
C. (A) \[\to \] (q), (B) \[\to \] (p), (C) \[\to \] (s), (D) \[\to \] (r)
D. (A) \[\to \] (s), (B) \[\to \] (q), (C) \[\to \] (p), (D) \[\to \] (r)
Answer» B. (A) \[\to \] (r), (B) \[\to \] (s), (C) \[\to \] (p), (D) \[\to \] (q)
Discussion
657.

Directions: Match Column-I with Column-II and select the correct answer using the codes given below the columns.   Column - I Column - II (A) Magnesium burnt in air (p) Powdery ash is formed (B) Iron reacts with copper sulphate solution (q) Color changes from blue to green (C) Coal is burnt in air (r) \[\text{C}{{\text{O}}_{\text{2}}}\]is formed (D) Photosynthesis (s) \[\text{C}{{\text{O}}_{\text{2}}}\]is used

A. (A) \[\to \] (p), (B) \[\to \] (q), (C) \[\to \] (r), (D) \[\to \] (s)
B. (A) \[\to \] (q), (B) \[\to \] (p), (C) \[\to \] (r), (D) \[\to \] (s)
C. (A) \[\to \] (q), (B) \[\to \] (p), (C) \[\to \] (s), (D) \[\to \] (r)
D. (A) \[\to \] (p), (B) \[\to \] (q), (C) \[\to \] (s), (D) \[\to \] (r)
Answer» B. (A) \[\to \] (q), (B) \[\to \] (p), (C) \[\to \] (r), (D) \[\to \] (s)
Discussion
658.

When carbon dioxide is passed through lime water, it turns milky due to two formation of

A. Calcium hydroxide
B. Sodium hydrogen carbonate
C. Calcium carbonate
D. None of these
Answer» D. None of these
Discussion
659.

Read the given statements and choose the correct option. (I) Iron and sulphur are mixed to form a black and yellow mixture. (II) Mixture of iron and sulphur is heated to form a non-magnetic shiny grey substance.

A. (I) is a chemical change
B. (II) is a physical change
C. Both are chemical changes
D. (I) is a physical change and (K) is a chemical change
Answer» E.
Discussion
660.

Magnesium ribbon bums in candle flame with

A. brilliant green light      
B. brilliant white light
C. brilliant red light          
D. brilliant yellow light
Answer» C. brilliant red light          
Discussion
661.

Blacksmith grinds edges of iron axe against a spinning wheel to sharpen it. Sparks of fire and heat is generated. On the basis of this statement choose the correct answer.

A. It is a physical change as only shape of axe changes.
B. It is a chemical change as heat is generated.
C. It is chemical change as iron turns into new metal.
D. None of these.
Answer» B. It is a chemical change as heat is generated.
Discussion
662.

Which of the following is the name of the process of obtaining salt by evaporation of sea water?

A. Amalgamation            
B. Sublimation
C. Crystallization   
D. Galvanization
Answer» D. Galvanization
Discussion
663.

For protection of iron pipes from corrosion they are coated with

A. Silver             
B. Copper
C. Aluminum                   
D. Zinc
Answer» E.
Discussion
664.

When magnesium is burnt, heat and light are produced. The burning of magnesium is a:

A. reversible change
B. physical change
C. chemical and exothermic change
D. chemical and endothermic change
Answer» D. chemical and endothermic change
Discussion
665.

Some pieces of chalk are mixed with water. In this change, how many new substances is/are formed?

A.  1
B.  2
C.  3
D.  No new substance is formed.
Answer» E.
Discussion
666.

Brown colour of the apple after cutting is a

A. Chemical change        
B. biological change
C. Physical change          
D. None of these
Answer» B. biological change
Discussion
667.

Which of the following is the chemical name of blue vitriol (neela thotha)?

A. Sulphuric acid
B. Calcium carbonate
C. Copper sulphate
D. Zinc sulphate
Answer» D. Zinc sulphate
Discussion
668.

Pollution of air is a

A. chemical change         
B. physical change
C. None of (a) or (b)       
D. Both (a) and (b)
Answer» B. physical change
Discussion
669.

On the basis of reactions given below Acetic acid + Sodium hydrogen carbonate \[\to \](i) (i)\[\text{+Ca(OH}{{\text{)}}_{\text{2}}}\to \text{(ii)+water}\] (i) and (ii) will be?

A.  \[\text{(i)}\,\text{CaC}{{\text{O}}_{\text{3}}}\text{;}\,\text{(ii)}\,\text{C}{{\text{O}}_{\text{2}}}\]
B.  \[\text{(i) }{{\text{H}}_{\text{2}}}\text{O;}\,\text{(ii)}\,\text{CaC}{{\text{O}}_{\text{3}}}\]
C.  \[\text{(i) C}{{\text{O}}_{\text{2}}};\,(\text{ii})\,\text{CaC}{{\text{O}}_{\text{3}}}\]
D.  \[\text{(i)}\,{{\text{H}}_{\text{2}}}\text{O;}\,\,\text{(ii)}\,\text{C}{{\text{O}}_{\text{2}}}\]
Answer» D.  \[\text{(i)}\,{{\text{H}}_{\text{2}}}\text{O;}\,\,\text{(ii)}\,\text{C}{{\text{O}}_{\text{2}}}\]
Discussion
670.

In a pressure-kerosene stove (i) We pump kerosene and convert it into vapours. (ii) The vapours are then ignited. Which of the following option is correct about the above statements?

A.  (i) is a chemical change; (ii) is a physical change.
B.  (i) is a physical change; (ii) is a chemical change.
C.  (i) and (ii) both are physical changes
D.  (i) and (ii) both are chemical changes
Answer» C.  (i) and (ii) both are physical changes
Discussion
671.

Some pieces of chalk were taken and mixed with water. In this change, how many new substances are formed?

A. 1
B. 2
C. 3
D. No new substances is formed
Answer» E.
Discussion
672.

Two changes are stated below: (i) A piece of magnesium gives of bright flames when burnt. (ii) A piece of iron glows red when heated strongly. Which of the above changes is a physical change?

A.  i only             
B.  ii only
C. Both i and ii                
D. neither i nor ii
Answer» C. Both i and ii                
Discussion
673.

A change in which the original substance can be obtained back by change of conditions is called:

A. reversible change        
B. physical change
C. chemical change         
D. Both (a) and (b)
Answer» E.
Discussion
674.

The ash which is collected after burning of magnesium ribbon is dissolved in water to give a solution X. What is the nature of the solution X when it is tested with indicators?

A.  It turns blue litmus red and phenolphthalein pink, hence it is an acidic solution.
B.  It turns red litmus blue and phenolphthalein pink, hence it is a basic solution.
C.  It turns blue litmus red and gives no colour with phenolphthalein, hence it is an acidic solution.
D.  It does not change colour of red or blue litmus and phenolphthalein, hence it is a neutral solution.
Answer» C.  It turns blue litmus red and gives no colour with phenolphthalein, hence it is an acidic solution.
Discussion
675.

A metal when left exposed to the atmosphere for some time gets coated with green basic carbonate. The metal in question is

A. Copper          
B. Nickel
C. Silver                          
D. Zinc
Answer» B. Nickel
Discussion
676.

Anaerobic bacteria digest animal waste and produce biogas (Changed A). The biogas is then burnt as fuel (Change B). The following statements are related to these changes. Choose the correct one.

A. A is a chemical change whereas B is a physical change.
B. 5 is a chemical change whereas A is a physical change.
C. Both A and 5 are physical changes.
D. Both A and B are chemical changes.
Answer» E.
Discussion
677.

In neutralization reaction acid reacts with a base to form salt and water and a lot of heat energy is given out. This reaction is:

A. an exothermic physical change
B. an endothermic chemical change
C. an exothermic chemical change
D. an endothermic physical change
Answer» D. an endothermic physical change
Discussion
678.

On adding a few drops of dilute sulphuric acid to the blue vitriol (copper sulphate) solution, we get a blue coloured solution. When we drop a shaving blade into this blue coloured solution blue colour changes to green after sometime. Which type of change is illustrated by this activity?

A. Physical change
B. Chemical change
C. Both of these
D. None of these
Answer» C. Both of these
Discussion
679.

...................... is a chemical change

A. Mixing of paint colours
B. Cleaning rust of a bridge
C. Pressing fibres to make paper
D. Baking a cake
Answer» E.
Discussion
680.

Select the one that is not a chemical change:

A. Dissolution of ammonia in water
B. Dissolution of carbon dioxide in water
C. Dissolution of oxygen in water
D. None of these
Answer» D. None of these
Discussion
681.

Choose correct option on the basis of statement (i) and (ii) (i) When hydrogen bums in oxygen, water is formed (ii) When water is electrolyzed, hydrogen and oxygen are formed.

A.  (i) is a physical change and (ii) is a chemical change
B.  (i) is a chemical change and (ii) is a physical change
C. Both (i) and (ii) are physical changes
D. Both (i) and (ii) are chemical changes
Answer» E.
Discussion
682.

Liquefied Petroleum Gas (L.P.G) used as kitchen fuel is supplied in the liquid form in the gas cylinders. When it comes out from cylinder it comes out as a gas which bums. Which of the following statements is correct?

A. The process of conversion of liquid to gas involves a chemical change.
B. The process of burning gas is a chemical change.
C. Both the above are correct.
D. None of these
Answer» C. Both the above are correct.
Discussion
683.

In the Process of convection:

A. Transfer of molecules do not occur.
B. Transfer of molecules occur.
C. No medium is required.
D. Transfer of free electrons occur.
E. None of these
Answer» C. No medium is required.
Discussion
684.

Which is the best method to prevent rusting?

A. Painting                      
B. Greasing
C. Galvanization    
D. Precipitation
Answer» D. Precipitation
Discussion
685.

Observe the given reaction sequence carefully.Acetic acid + Sodium hydrogen carbonate \[\xrightarrow{{}}\](i)\[(i)+Ca{{(OH)}_{2}}\xrightarrow{\,}\,(ii)+Water\]What could (i) and (ii) be?

A. (i)(ii)\[CaC{{O}_{3}}\]\[C{{O}_{2}}\]               
B. (i)(ii)\[{{H}_{2}}O\]\[CaC{{O}_{3}}\]               
C. (i)(ii) \[C{{O}_{2}}\]\[CaC{{O}_{3}}\]               
D. (i)(ii)\[{{H}_{2}}O\]\[C{{O}_{2}}\]
Answer» D. (i)(ii)\[{{H}_{2}}O\]\[C{{O}_{2}}\]
Discussion
686.

What kind of change is undergone when wheat flour is made into a chapati?

A.  Physical change.
B.  Reversible, chemical change.
C.  Irreversible, chemical change.
D.  Change of state.
Answer» D.  Change of state.
Discussion
687.

Direction:  Look at the following diagram carefully and answer the following questions: On the basis of given figure read the following statements and choose the correct option. (i) Oil present in test tube A cut off the presence of air. (ii) \[\text{CaC}{{\text{l}}_{\text{2}}}\] is used for absorbing moisture in the test tube C. (iii) Rusting decreases on adding saline water in test tube B.

A.  I and III are correct
B.  I and II are correct
C. Only III is correct
D. All of the above
Answer» C. Only III is correct
Discussion
688.

Direction:  Look at the following diagram carefully and answer the following questions: Rusting of iron nail will be faster in which of following test tube.

A. A                                 
B. Both A and B
C. B                                 
D. Equal in A, B and C
Answer» D. Equal in A, B and C
Discussion
689.

DIRECTIONS: On the basis of following diagram/ picture answer the questions given below: What is the name of the process that is shown in the given figure?

A. Evaporation                
B. Sublimation
C. Neutralization             
D. Crystallization
Answer» E.
Discussion
690.

DIRECTIONS: On the basis of following diagram/ picture answer the questions given below: Which of the following changes represent a chemical change?

A. Only (i)                       
B. Only (ii)
C.  (i) and (ii)          
D. None of the two
Answer» D. None of the two
Discussion
691.

DIRECTIONS: Read the following two statements carefully and choose the correct options. (i) Condensation of steam is not a chemical change (ii) Physical change is a permanent and irreversible change

A. Statement (i) is correct while statement (ii) is incorrect.
B. Statement (ii) is correct while statement (i) is incorrect.
C. Both statements are correct
D. Both statements are incorrect.
Answer» B. Statement (ii) is correct while statement (i) is incorrect.
Discussion
692.

DIRECTIONS: Read the following two statements carefully and choose the correct options. (i) Lime water turns milky due to presence of calcium bicarbonate. This is a confirmatory test of\[\text{C}{{\text{O}}_{\text{2}}}\]. (ii) Digestion of food and melting of wax are considered as similar type of changes.

A. Statement (i) is correct while statement (ii) is incorrect.
B. Statement (ii) is correct while statement (i) is incorrect.
C. Both statements are correct
D. Both statements are incorrect.
Answer» E.
Discussion
693.

DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Explosion of a fire cracker is a physical change. Reason (R): A physical change is a reversible change.

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer» E.
Discussion
694.

DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Decay and decomposition of dead organic matter (leaves and dead animal bodies) by microbes is a chemical reaction. Reason (R): In a chemical change original substance and its properties are changed to new material with new properties.

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer» B. Both A and R are true but R is not the correct explanation of A.
Discussion
695.

Rising of mercury in the thermometer is due to:

A. Contraction of mercury on heating.
B. Expansion of mercury on heating.
C. Movement of the patient.
D. Glass Covering of thermometer.
E. None of these
Answer» C. Movement of the patient.
Discussion
696.

DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Coating an iron sheet with a layer of zinc is called galvanization. Reason (R): The process which converts iron to iron oxide in the presence of moisture and air is called rusting.

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer» B. Both A and R are true but R is not the correct explanation of A.
Discussion
697.

DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Burning of paper is a physical change. Reason (R): The products formed on burning of paper cannot be converted back to paper.

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer» E.
Discussion
698.

DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Some changes which result in formation of new substances are called chemical changes. Reason (R): Chemical changes are irreversible.

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer» C. A is true but R is false.
Discussion
699.

DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Formation of rust is a chemical change. Reason (R): For formation of rust, iron must be exposed to air and water.

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer» C. A is true but R is false.
Discussion
700.

DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Tearing of a paper sheet into small pieces is a chemical change. Reason (R): It is not possible to rejoin small pieces of paper to get back the original paper sheet.

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer» E.
Discussion