| Class: 9 | Science |
| Chapter: 2 | Is Matter Around us pure? |
| Contents: | MCQ Online Test with Answers |
Class 9 Science Chapter 2 MCQ with Answers for 2021-2022
Class 9 Science Chapter 2 MCQ Online tests with solution and explanation. There are about 70 questions in the form of objectives with four choices. These MCQ covers the entire chapter of grade 9 Science NCERT Chapter 2. For the preparation of unit tests or terminal exams, students may use these questions as revision.
Q1
The property/properties which enable copper metal to be used for making electric wires is / are
[A]. Copper metal is malleable and ductile
[B]. Copper metal is a good conductor of electricity
[C]. Copper metal is ductile and has low electrical resistance
[D]. Copper metal is sonorous and an excellent conductor of electricity
Answer: Option C
Explanation:Copper is a good conductor of electricity. It means that it offers very low electric resistance. Also, it is highly ductile due to which it can be drawn into very thin wires.
Q2
Anushka is completed her science chapter where she wrote some statements. She wants to know whether the statements are correct or not? Anushka wants to take help from you:
[A]. An element cannot be split up into two or more simpler substances because it is made of only one kind of atoms.
[B]. There are 118 elements known at present, out of which 94 elements, occur in nature while the remaining 24 elements have been prepared artificially.
[C]. 11 elements are gases whereas only two elements mercury and bromine a liquid at room temperature.
[D]. All of the above
Answer: Option D
Explanation:Here, all these statements are correct. Hence your answer will be option [D].
Q3
Which of the following are physical changes?
[A]. Melting of iron metal, Rusting of iron, Bending of an iron rod
[B]. Melting of iron metal, Rusting of iron, Drawing a wire of iron metal
[C]. Melting of iron metal, Bending of an iron rod, Drawing a wire of iron metal
[D]. Rusting of iron, Bending of an iron rod, Drawing a wire of iron metal
Answer: Option C
Explanation:Melting of iron metal, bending of an iron rod and drawing a wire of iron metal are physical changes, because in three processes, iron changes its form, not the chemical composition. In rusting of iron, its chemical composition is changed.
Q4
In a quiz competition, you are asked a question where you have to choose the statement which is/ are incorrect?
[A]. The electric wires are made of copper and Aluminium metals because they are very good conductors of electricity.
[B]. Only one metal, mercury, is in liquid state at room temperature.
[C]. Metal gallium has a such a low melting point that it starts melting in hand by the heat of our body.
[D]. Sodium and potassium metals have high densities than iron.
Answer: Option D
Explanation:Generally, metals have high densities this refers that metals are heavy substances. As an example, the density of iron metal is 7.8 gram per centimetre cube which is quite high. There is some exception such as sodium and potassium metals have low densities. Thus, they are very light metals.
Q5
In a science quiz competition, Sneha are asked a question where she had to choose the statement which was/were incorrect?
[A]. A suspension is a heterogeneous mixture in which the small particles of a solid are spread throughout a liquid without dissolving in it.
[B]. If a beam of light passed through a chalk and water suspension, it is scatter the beam of light and renders its path visible inside it.
[C]. A colloid is a kind of solution in which the size of solute particles is intermediate between those in true solution and those in suspensions.
[D]. In a true solution (like sugar solution), the solid particles are small and they can easily scatter light rays falling on them.
Answer: Option D
Explanation:In a true solution (like sugar solution), the solid particles are so small that they cannot scatter light rays falling on them.
For example, if a beam of light (from a torch) is put on true solution (like sugar solution) kept in a beaker in a dark room, the path of light beam is invisible inside the solution when seen from the side. The beam of light can become visible only when the solid particles are big enough to reflect light falling on them. Since the particles of a true solution do not a scatter light.
Q6
Read the following sentences carefully, and choose the incorrect one:
[A]. In a colloidal solution or colloid the particles are big enough to scatter light.
[B]. The scattering of light by colloidal particles is known as “Tyndall effect”.
[C]. Colloids are heterogeneous in nature, though they appear to be homogeneous.
[D]. The particles of most of the colloids can be seen with a microscope.
Answer: Option D
Explanation:It is the properties of colloids that the size of particles in a colloid is bigger than those in a true solution but smaller than those in a suspension. It is between 1 nm and 100 nm in diameter.
The particles of most of the colloids or colloidal solution cannot be seen even with a microscope.
Q7
Which of the following statement is or are incorrect?
[A]. A solution in which more quantity of solute can be dissolved without raising its temperature, is called an unsaturated solution.
[B]. A solution in which no more solute can be dissolved at that temperature is called a saturated solution.
[C]. If a saturated solution at a particular temperature is heated to a higher temperature, then it becomes unsaturated.
[D]. None of the above.
Answer: Option D
Explanation: Here, are all the statements are correct. Hence, your answer will be option [D].
Q8
Which of the following statement is or are incorrect?
[A]. Centrifugation is a method for separating the suspended particles of a substance from a liquid in which the mixture is rotated at a high speed in a centrifuge.
[B]. The process of centrifugation is used in dairies to separate cream from milk.
[C]. The separation of a dissolved solids from a liquid can be done by only one methods as evaporation.
[D]. None of the above.
Answer: Option C
Explanation:The separation of a dissolved solids from a liquid can be done by a number of other methods such as evaporation, crystallization, distillation and chromatography etc.
Q9
Consider the following statements and choose the correct one:
[A]. The separation of two immiscible liquids by separating funnel depends on the difference in their densities.
[B]. A mixture of petrol and water can also be separated by using a separating funnel.
[C]. A mixture of mercury, water and benzene can be separated by separating funnel.
[D]. All the above.
Answer: Option D
Explanation:Here, are all the statements are correct. Hence, your answer will be option [D].
Q10
Consider the following statements and choose the correct one(s):
[A]. The elements which shows some properties of metals and some other properties of nonmetals are called metalloids.
[B]. The mixture is a substance which consists of two or more elements or compounds not chemically combined together.
[C]. All the suspension and colloids are considered as heterogeneous mixtures.
[D]. All the above.
Answer: Option D
Explanation:Here, are all the statements are correct. Hence, your answer will be option [D].
What is a Solution?
A solution is a homogeneous mixture of two or more substances.
What are the main constituents of air?
The two main constituents of air are oxygen (21%) and nitrogen (78%).
What is Suspension?
A non-homogeneous systems in which solids are dispersed in liquids, are called suspensions. A suspension is a heterogeneous mixture in which the solute particles do not dissolve but remain suspended throughout the bulk of the medium.
Write down two properties of Colloids?
1. Colloids are big enough to scatter a beam of light passing through it and make its path visible.
2. They do not settle down when left undisturbed, that is, a colloid is quite stable.
Updated Contents and NCERT Solutions
We update NCERT Textbook Solutions and other study material as per the change of syllabus or on demand of students also. Provide feedback to improve the quality of the contents. Every thing on Tiwari Academy is free to use.
