NCERT MCQ CLASS-9 CHAPTER-2 | IS MATTER AROUND US IS PURE? | EDUGROWN

NCERT MCQ ON IS MATTER AROUND US IS PURE?

Question 1.
Which of the following statements are true for pure substances?
(i) Pure substances contain only one kind of particles
(ii) Pure substances may be compound or mixtures
(iii) Pure substances have the same composition throughout
(iv) Pure substances can be exemplified by all elements other than nickel
(a) (i) and (ii)
(b) (i) and (iii)
(c) (iii) and (iv)
(d) (ii) and (iii)

Answer: (b) (i) and (iii)

Question 2.
Rusting of an article made up of iron is called
(a) corrosion and it is a physical as well as chemical change
(b) dissolution and it is a physical change
(c) corrosion and it is a chemical change
(d) dissolution and it is a chemical change

Answer: (c) corrosion and it is a chemical change

Question 3.
A mixture of Sulphur and Carbon disulphide is
(a) heterogeneous and shows Tyndall effect
(b) homogeneous and shows Tyndall effect
(c) heterogeneous and does not show Tyndall effect
(d) homogeneous and does not show Tyndall effect

Answer: (d) homogeneous and does not show Tyndall effect

Question 4.
Tincture of iodine has antiseptic properties. This solution is made by dissolving
(a) iodine in potassium iodide
(b) iodine in vaseline
(c) iodine in water
(d) iodine in alcohol

Answer: (d) iodine in alcohol

Question 5.
Which of the following are homogeneous in nature?
(i) ice
(ii) wood
(iii) soil
(iv) air
(a) (i) and (iii)
(b) (ii) and (iv)
(c) (i) and (iv)
(d) (iii) and (iv)

Answer: (c) (i) and (iv)

Question 6.
Blood and sea water are
(a) both mixtures
(b) both are compounds
(c) blood is a mixture whereas sea water is a compound
(d) blood is a compound and sea water is a mixture

Answer: (a) both mixtures

Question 7.
Sol and gel are examples of
(a) Solid-solid colloids
(b) Sol is a solid-liquid colloid and gel is liquid solid colloid
(c) Sol is solid-solid colloid and gel is solid-liquid colloid
(d) Sol is a liquid-solid colloid and gel is a solid-liquid colloid

Answer: (b) Sol is a solid-liquid colloid and gel is liquid solid colloid

Question 8.
In a water-sugar solution
(a) water is solute and sugar is solvent
(b) water is solvent and sugar is solute
(c) water is solute and water is also solvent
(d) none of these

Answer: (b) water is solvent and sugar is solute

Question 9.
Boron and carbon are
(a) metalloids
(b) metalloid and non-metal respectively
(c) metal
(d) non-metal and metalloid respectively

Answer: (b) metalloid and non-metal respectively

Question 10.
Which of the following are physical changes?
(i) Melting of iron metal
(ii) Rusting of iron
(iii) Bending of an iron rod
(iv) Drawing a wire of iron metal
(a) (i), (ii) and (iii)
(b) (i), (ii) and (iv)
(c) (i), (iii) and (iv)
(d) (ii), (iii) and (iv)

Answer: (c) (i), (iii) and (iv)

Question 11.
Which of the following are chemical changes?
(i) Decaying of wood
(ii) Burning of wood
(iii) Sawing of wood
(iv) Hammering of a nail into a piece of wood
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)

Answer: (a) (i) and (ii)

Question 12.
Two substances, A and B were made to react to reaction a third substance, A₂B according to the following
2 A + B → A₂B
Which of the following statements concerning this reaction are incorrect?
(i) The product A₂B shows the properties of substances A and B
(ii) The product will always have a fixed composition
(iii) The product so formed cannot be classified as a compound
(iv) The product so formed is an element
(a) (i), (ii) and (iii)
(b) (ii), (iii) and (iv)
(c) (i), (iii) and (iv)
(d) (ii), (iii) and (iv)

Answer: (c) (i), (iii) and (iv)

Question 13.
Two chemical species X and Y combine together to form a product P which contains both X and Y
X + Y → P
X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following concerning the species X, Y and P are correct?
(i) P is a compound
(ii) X and Y are compounds
(iii) X and Y are elements
(iv) P has a fixed composition
(a) (i), (ii) and (iii)
(b) (i), (ii) and (iv)
(c) (ii), (iii) and (iv)
(d) (i), (iii) and (iv)

Answer: (d) (i), (iii) and (iv)

Question 14.
Which of the following methods would you use to separate cream from milk?
(a) Fractional distillation
(b) Distillation
(c) Centrifugation
(d) Filtration

Answer: (c) Centrifugation

Question 15.
Cooking of food and digestion of food:
(a) are both physical processes
(b) are both chemical processes
(c) cooking is physical whereas digestion is chemical
(d) cooking is chemical whereas digestion is physical

Answer: (b) are both chemical processes

---