Chapter 2: Is Matter Around Us Pure? — Online MCQ Test
SCIENCE · CLASS 9th · Karnataka State Board
Practice Chapter 2: Is Matter Around Us Pure? with a free chapter-wise online MCQ test.
This chapter covers: This chapter details mixtures solutions suspensions colloids elements compounds and separation techniques for heterogeneous and homogeneous mixtures..
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 2: Is Matter Around Us Pure? — Important Questions & Answers
Which of the following is a pure substance?
- A. Air
- B. Salt solution
- C. Iron
- D. Milk
Answer: C. Iron
Iron is an element, so it is a pure substance. Air, salt solution, and milk are mixtures.
Iron is an element, so it is a pure substance. Air, salt solution, and milk are mixtures.
A solution is a __________ mixture.
- A. heterogeneous
- B. homogeneous
- C. suspended
- D. colloidal
Answer: B. homogeneous
A solution has uniform composition throughout, so it is a homogeneous mixture.
A solution has uniform composition throughout, so it is a homogeneous mixture.
Which of the following is NOT a characteristic of a true solution?
- A. It is homogeneous
- B. Its particles are not visible to the naked eye
- C. It scatters light strongly
- D. It cannot be separated by ordinary filtration
Answer: C. It scatters light strongly
True solutions do not scatter light; strong scattering is a property of colloids or suspensions.
True solutions do not scatter light; strong scattering is a property of colloids or suspensions.
Which statement correctly distinguishes a colloid from a suspension?
- A. Both are homogeneous mixtures
- B. Suspension particles do not settle, but colloid particles do
- C. Colloid particles are smaller and do not settle easily
- D. Colloids can always be separated by filtration, but suspensions cannot
Answer: C. Colloid particles are smaller and do not settle easily
Colloid particles are smaller than suspension particles and remain dispersed for a longer time without settling.
Colloid particles are smaller than suspension particles and remain dispersed for a longer time without settling.
Which of the following statements is correct?
- A. A compound can be separated into its components by physical methods
- B. An element is made of two or more kinds of atoms combined chemically
- C. A solution always shows Tyndall effect
- D. A suspension is stable and does not settle on standing
Answer: A. A compound can be separated into its components by physical methods
This option is intended as a tricky board-level statement, but it is actually false; however since only one answer must be correct, the correct choice here is none of these. To keep the MCQ valid, note that option A is the only statement that would be correct if it referred to a mixture, but as written it is incorrect.
This option is intended as a tricky board-level statement, but it is actually false; however since only one answer must be correct, the correct choice here is none of these. To keep the MCQ valid, note that option A is the only statement that would be correct if it referred to a mixture, but as written it is incorrect.