Case study based questions from is matter around us pure

CASE STUDY BASED QUESTIONS                                

Q.1 Read the passage and answer the questions given, one mark questions

Anything that occupies some space, having mass, volume and can be felt by one or more out of five senses is called matter. The purest form of matter is called an element. An element is a substance which cannot be split up into two or more simpler substances by the usual chemical methods of applying heat, light or electric energy.

A pure substance consists of a single type of particles. All the elements and compounds are pure substances because they contain only one kind of particles. eg. Hydrogen, Carbon, Oxygen, Carbon-monoxide, Copper, Gold, Silver. A pure substance has a fixed composition as well as a fixed boiling point and melting point. The presence of impurities generally increases the melting and boiling point of the pure substances

i)  Which of the statement is true about pure substances?

a.   Homogeneous mixtures are pure as they have same composition throughout.

b.   22 carat gold is pure in nature.

c.    Elements are not pure in nature.

d.    Gold is pure in nature.

Ans- d

ii) The boiling point of pure water is 100^oC. What likely be the effect on the boiling point of water if 150 gm NaCl is added to one litre water.

a.      Increases

b.     Decreases

c.      Remain same

d.     Does not effected

Ans- a

Q.2 Read the following and answers the questions.

A homogeneous mixture of two or more substances called a true solution. it consists of solute and solvent. The particle size of true solution in less than 1 nanometer. A suspension is a heterogeneous mixture in which the solute particle does not dissolve but remain suspended throughout the bulk of the medium. A colloid is a mixture that is actually heterogeneous but appears to be homogeneous as the particles are uniformly spread throughout the solution.

(i) which one of the following is most stable? 

A)True solution

B)Suspensions

C)Colloids

D) both A and B

Ans-A

ii) which type of mixture can be separated by filtration? 

A)True

B)Suspensions

C)Colloids

D)All of these

Ans-B

iii) which statement is incorrect about Tyndall effect. *

A)True solution show Tyndall effect

B)Suspensions show Tyndall effect

C)Colloid show Tyndall effect

D)Both B and C show Tyndall effect

Ans-A

iv) Which is the correct order of stability of solution *

A) True < Colloid<Suspension

B)Colloid<Suspension<True

C)Colloid<True<Suspension

D)Suspension<Colloid<True

Ans- D

ASSERTION AND REASONING BASED QUESTIONS

Q(3) Assertion :- an element is purest form of matter. 

       Reason --- an element is made up of same kind of atoms .

(a) If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.

(b) If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.

(c) If the Assertion is correct but Reason is incorrect.

(d) If both the Assertion and Reason are incorrect.

Ans-a

Q(4)Assertion:- Milk and starch will show tyndall effect. Reason:- particle of milk and starch scatter the beam of light.

(a) If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.

(b) If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.

(c) If the Assertion is correct but Reason is incorrect.

(d) If both the Assertion and Reason are incorrect.

Ans-a

     Competency based questions

Q(5)Tincture of iodine has antiseptic properties. This solution is made by dissolving *

(a) iodine in potassium iodide

b) iodine in oil

(c) iodine in water

(d) iodine in alcohol

Ans-d

Q(6) in which of the following is a mixture-

(a)Sea water

(b)Calcium carbonate

(c)Oxygen

(d)Iron

Ans-a

Q(7)identify the dispersed phase and dispersion medium of a given colloid. Colloid - Fog 

z

Ans-a

Q(8)which type colloidal solution is formed when a liquid present in liquid ?

   a. Gel

   b. Emulsion

   c. Aerosol

   d. Solid Sol

Ans-b

CRITICAL THINKING AND NUMERICAL BASED QUESTION

Q(9)0.5 gram of salt is dissolved in 25 gram of water. What is the percentage amount of salt in the solution (calculate by using mass by mass percentage formula) *

(a)1.96%

(b)3.00%

©4.00%

(d)2.5%

Ans-a

I. Read the following and answers and questions.(5)

A homogenous mixture of two or more substances called a true solution. It consists of solute and solvent. The particle size of true solution is less than 1 nanometer. A suspension is a heterogenous mixture in which the solute particle does not dissolve but remain suspended throughout the bulk of the medium. A colloid is a mixture that is actually heterogenous but appears to be homogeneous as the particle are uniformly spread throughout the solution.

i). Which one of the following is most stable?

a. True solution

b. Suspension

c. Colloids

d. Both a and b

ii). Which types of mixture can be separated by filtration

a. True solution

b. Suspension

c. Colloids

d. All of above

  iii) .Which types of effect  shown by solution B

 

(a)Lustre    (b) sonorous  (c)ductile  (d)Tyndall 

iv).when Shreyanshi  was suffering from fever the Doctor had asked his parents to check his temperature every two hours and also to keep a record. he was a thermometer that has a certain metal in liquid state inside it.generally metals are solid in nature which one of the following metal is found in liquid state at room temperature.

 (a) Na        (b) Al           (c) Hg              (d) Fe                                                                                     

v)Emulsion  solution is a colloidal solution in which the dispersed phase is a…… while the dispersion medium is a……                                                                                                                  (a)Liquid, liquid    (b)Liquid, solid  (c)Solid ,liquid     (d)Liquid ,gas                                                      Q.2 A solution contains 40g of sugar in 320g of water.Calculate the concentration in terms of mass by mass percentage of the solution.