Class 9 Practice Level 3 – Set 1 – Is Matter Around Us Pure?

Total questions: 15

Which of the following statements best describes a heterogeneous mixture?

Topic: Mixtures

Its composition is uniform throughout.

Its components are evenly distributed.

It has visibly distinguishable parts.

It cannot be separated by physical means.

None

Which of the following methods can be used to determine the purity of a substance?

Topic: Pure Substances

Measuring its boiling point

Checking its colour

Observing its physical state

Measuring its density

None

Which of the following is not an advantage of using alloys over pure metals?

Topic: Alloys

Increased strength

Improved resistance to corrosion

Lower melting point

Homogeneous composition

None

Which of the following statements is true regarding chromatography?

Topic: Chromatography

It separates components based on their densities.

It is used only for liquid mixtures.

It can be used to separate and identify components of a mixture.

It relies on the solubility of substances.

None

Which of the following is an incorrect statement about mixtures?

Topic: Mixtures

Mixtures have variable composition.

The components of a mixture retain their individual properties.

Mixtures can only be separated by chemical means.

Mixtures can be homogeneous or heterogeneous.

None

Which of the following is true about the solubility of gases in liquids?

Topic: Solutions

It increases with increasing temperature.

It decreases with increasing pressure.

It decreases with increasing temperature.

It is not affected by pressure.

None

Which of the following statements is true about a saturated solution?

Topic: Solutions

It contains the maximum amount of solute that can be dissolved at a given temperature.

It cannot be diluted.

It has undissolved solute settled at the bottom.

It can dissolve more solute if stirred.

None

Which of the following methods can be used to separate a colloidal solution?

Topic: Colloids

Filtration

Centrifugation

Distillation

Sublimation

None

Which of the following properties can be used to identify a pure substance?

Topic: Pure Substances

Colour

Melting point

Volume

Mass

None

10.

Which of the following statements about steel is incorrect?

Topic: Alloys

It is an alloy of iron and carbon.

It is stronger than pure iron.

It has a higher melting point than pure iron.

It is more resistant to corrosion than pure iron.

None

11.

In paper chromatography, what is the role of the solvent?

Topic: Chromatography

To dissolve the paper

To carry the sample spots along the paper

To react with the sample

To provide a stationary phase

None

12.

Which of the following is an example of a lyophilic colloid?

Topic: Colloids

Milk

Gold solution

Starch solution

Ferric hydroxide solution

None

13.

Which factor does not affect the rate of dissolution of a solid in a liquid?

Topic: Solutions

Temperature

Surface area of the solid

Pressure

Stirring

None

14.

Which separation technique would be most effective for purifying a solid organic compound?

Topic: Separation Techniques

Filtration

Recrystallization

Decantation

Chromatography

None

15.

Which of the following statements about pure substances is incorrect?

Topic: Pure Substances

They have a fixed composition.

They cannot be separated by physical means.

They have variable properties throughout.

They include elements and compounds.

None

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Class 9 Practice Level 3 – Set 1 – Is Matter Around Us Pure?

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