Is Matter Around Us Pure
Is Matter Around Us Pure, Compound, Mixture, Chemistry, IX, Science
Questions
Assertion: Oxygen is an element.
Reason: It cannot be decomposed by a physical or a chemical process.
Directions: In the question given below, there are two statements labelled as Assertion (A) and Reason (R). Mark your answer as per the codes provided below:
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.
E. Both A and R are false.
- A
- B
- C
- D
- E
Which of the following is/are true about hetrogenous mixtures?
a. An opaque suspension is a hetrogenous mixture.
b. Collodial solutions are hetrogenous mixtures.
c. A mixture of two miscible liquids is a hetrogenous mixture.
- Only a
- Only b
- Only c
- Only a and b
- All of these
Which of the following is a true statement for a pure substance or a compound?
a. The elements in a compound are present in a definite proportion by weight.
b. It can be broken down into a simpler type of matter (elements) by chemical means but not by physical means.
c. Properties of a compound are an average of the properties of its constituents.
- Only a
- Only b
- Only c
- Only a and b
- All of these
Which of the following pairs of colloids and their dispersed phase is correct?
- Smoke - gas
- Shaving cream - liquid
- Milk of magnesia - liquid
- Cheese - liquid
- Sponge - solid
Which of the following shows Tyndall effect?
a. Soda water
b. Milk
c. Muddy water
- Only a
- Only b
- Only c
- Only a and c
- All of these
Which of the following is false about a Solution?
- It is a heterogeneous mixture.
- The particles of a solution are very small and invisible to the naked eye.
- The path of light is not visible in a solution.
- The constituents of a solution cannot be separated by sedimentation.
- The constituents of a solution cannot be separated by filtration.
Match the Column - I with the Column - II.
| Column - I | Column - II |
| a. Iron | 1. Colloid |
| b. Urea | 2. Element |
| c. Air | 3. Compound |
| d. Coloured gemstone | 4. Mixture |
- a - 1, b - 2, c - 3, d - 4
- a - 1, b - 4, c - 3, d - 2
- a - 2, b - 3, c - 4, d - 1
- a - 3, b - 2, c - 1, d - 4
- a - 4, b - 1, c - 2, d - 3
Which of the following statements is/are correct?
a. The concentration of a solution is the amount of solute present per unit volume or per unit mass of the solution/solvent.
b. The particles of a suspension are called the dispersed phase.
c. On heating of two elements in a mixture strongly we get a compound, which has totally different properties as compared to the combining elements.
- Only a
- Only b
- Only c
- Only a and c
- All of these
Which of the following processes is used for the separation of insoluble solid particles from a solid-liquid mixture, if the solid particles are very small and pass through a filter paper?
- Chromatography
- Crystallisation
- Sublimation
- Centrifugation
- Distillation
Which of the following is not an application of centrifugation process of separation?
- Separation of cream from milk in dairies.
- Used in washing machines to squeeze out water from clothes.
- Used in laboratories to separate collodial particles from their solutions.
- Used in laboratories to separate a mixture of acetone and water.
- Used in diagnostic labs for blood and urine tests.
Which of the following statements is/are correct?
a. Emulsion and gel are both collodial solutions.
b. Ultracentrifugation is used to separate the particles of a collodial solution.
c. Pigments of natural colours can be separated by chromatography.
- Only a
- Only b
- Only c
- Only a and c
- All of these
Which of the following is/are correct regarding the statement- 'air is a mixture and not a pure substance'?
a. The amounts of gases present in air at different places varies.
b. The properties of air are the properties of its constituents.
c. The different gases present in air can be separated by the process of fractional distillation of liquid air.
- Only a
- Only b
- Only c
- Only a and c
- All of these
A mixture of n-hexane and n-heptane can be separated through the process of _____________ method.
- chromatography
- distillation
- crystallisation
- fractional distillation
- centrifugation
Which of the following is the criteria to use chromatography for separating components of a mixture?
- This method used to separate a mixture comprising of solutes that dissolve in the same solvent.
- This method is used for the separation of a mixture containing two miscible liquids that boil without decomposing and have a large difference between their boiling points.
- Two immiscible liquids are separated by this method.
- In case the difference in the boiling points of the liquids is less than 25 kelvin temperature, we use the chromatography method.
- This method is used as a separation and purification method that involves the precipitating of solid crystals from its saturated solution on cooling.
Which of the following statements is/are correct?
a. When a beam of light is passed through a collodial solution, the path of light gets illuminated.
b. When an electric current is passed through a colloidal solution, particles move towards the oppositely charged electrodes.
c. When an electric current is passed through an electrolyte solution, particles move towards the oppositely charged electrodes.
- Only a
- Only b
- Only c
- Only a and b
- a, b and c