Quiz - Composition Of Matter -i (Physical Chemical Chenge And Element Compound And Mixture)

1. I. Chemical changes are not easily reversible. II. Chemical changes produce new substances. III. Chemical changes do not involve large energy changes. Which of the above statement are correct

I

I and II

I and III

II and III

I, II and III

The correct answer is I and II. Chemical changes are not easily reversible because they involve the formation of new substances with different properties. This is supported by statement II, which states that chemical changes produce new substances. However, statement III is incorrect as chemical changes often involve large energy changes, such as in exothermic or endothermic reactions.

Explanation

The correct answer is I and II. Chemical changes are not easily reversible because they involve the formation of new substances with different properties. This is supported by statement II, which states that chemical changes produce new substances. However, statement III is incorrect as chemical changes often involve large energy changes, such as in exothermic or endothermic reactions.

2. I.The element present in a compound can be separated by easy physical processes. II. A solution is a mixture. III. Mixture vary widely in their composition. Which of the above statement are correct

I

I and II

I and III

II and III

I,II and III

The correct answer is II and III.

Statement II is correct because a solution is a type of mixture where two or more substances are evenly distributed.

Statement III is correct because mixtures can have varying compositions, meaning they can contain different amounts of substances mixed together.

Statement I is incorrect because elements in a compound cannot be separated by easy physical processes. Compounds are formed when two or more elements chemically combine, and they can only be separated by chemical processes.

Explanation

The correct answer is II and III.

Statement II is correct because a solution is a type of mixture where two or more substances are evenly distributed.

Statement III is correct because mixtures can have varying compositions, meaning they can contain different amounts of substances mixed together.

Statement I is incorrect because elements in a compound cannot be separated by easy physical processes. Compounds are formed when two or more elements chemically combine, and they can only be separated by chemical processes.

3. Which of the following is not a phsical change?

The sublimation of Iodine.

Tearing of a piece of cloth.

Burning of wax in a candle.

Dissolving sugar in a tea.

Dehydrating milk to get milk powder.

Burning of wax in a candle is not a physical change because it involves a chemical reaction. During burning, the wax undergoes combustion, which is a chemical process that results in the formation of new substances, such as carbon dioxide and water vapor. Physical changes, on the other hand, do not involve the formation of new substances and only alter the physical properties of a substance, such as its shape, size, or state of matter.

Explanation

Burning of wax in a candle is not a physical change because it involves a chemical reaction. During burning, the wax undergoes combustion, which is a chemical process that results in the formation of new substances, such as carbon dioxide and water vapor. Physical changes, on the other hand, do not involve the formation of new substances and only alter the physical properties of a substance, such as its shape, size, or state of matter.

4. Which of the following mixtures may be separated using a separating funnel ? I. Water and Mercury II. Water and common salt III. Water and sulphuric acid

I

II

III

I and II

I and III

Water and mercury can be separated using a separating funnel because they are immiscible liquids, meaning they do not mix together. Water is denser than mercury, so when the mixture is poured into a separating funnel, the mercury will settle at the bottom and can be drained out separately from the water.

Explanation

Water and mercury can be separated using a separating funnel because they are immiscible liquids, meaning they do not mix together. Water is denser than mercury, so when the mixture is poured into a separating funnel, the mercury will settle at the bottom and can be drained out separately from the water.

5. I. Physical changes are easily reveresible. II. Physical change do not produce new substance III. Physical change do not involve change in mass. Which of the above statement are correct?

I

I and II

I and III

II and III

I, II and III

Physical changes are easily reversible because they do not involve a change in the chemical composition or structure of a substance. Therefore, the original substance can be restored by reversing the physical change. Physical changes also do not produce new substances, as the arrangement or state of the particles may change, but the chemical identity remains the same. Additionally, physical changes do not involve a change in mass, as the total mass of the substances before and after the change remains constant. Therefore, all three statements are correct.

Explanation

Physical changes are easily reversible because they do not involve a change in the chemical composition or structure of a substance. Therefore, the original substance can be restored by reversing the physical change. Physical changes also do not produce new substances, as the arrangement or state of the particles may change, but the chemical identity remains the same. Additionally, physical changes do not involve a change in mass, as the total mass of the substances before and after the change remains constant. Therefore, all three statements are correct.

6. Which of the folloewing is not likely to be and element ? I. When heated gives off a gas and leaves a solid residue. II. Burns in air to form carbon dioxide and water. III.Changes into a liquid and gives off a gas.

I

II

III

I and II

I,II and III

not-available-via-ai

Explanation

not-available-via-ai

7. Which of the following processes would you use to obtain the components of a solution of copper sulphate in water

Use of separating funnel

Distillation

Evaporation

Chromatography

Sublimation

Evaporation would be the most suitable process to obtain the components of a solution of copper sulphate in water. This process involves heating the solution, causing the water to evaporate and leaving behind the copper sulphate crystals. Separating funnel is used to separate immiscible liquids, distillation is used to separate liquids with different boiling points, chromatography is used to separate components based on their affinity for a stationary phase, and sublimation is used to separate a solid from a gas without going through the liquid phase.

Explanation

Evaporation would be the most suitable process to obtain the components of a solution of copper sulphate in water. This process involves heating the solution, causing the water to evaporate and leaving behind the copper sulphate crystals. Separating funnel is used to separate immiscible liquids, distillation is used to separate liquids with different boiling points, chromatography is used to separate components based on their affinity for a stationary phase, and sublimation is used to separate a solid from a gas without going through the liquid phase.

8. Which of the following mixture may be separated by using sublimation ? I. Iodine and sand II. Sand and sulphur III. Sand and ammonium chloride.

I

II

III

I and II

I and III

Iodine and ammonium chloride can be separated by sublimation because both substances have the property of sublimation, which means they can change from a solid directly into a gas without going through the liquid phase. Sand, on the other hand, cannot be separated by sublimation as it does not have this property. Therefore, the correct answer is I and III.

Explanation

Iodine and ammonium chloride can be separated by sublimation because both substances have the property of sublimation, which means they can change from a solid directly into a gas without going through the liquid phase. Sand, on the other hand, cannot be separated by sublimation as it does not have this property. Therefore, the correct answer is I and III.

9. Which of the following process involves fractional distillation? I. Separation of the component of liquid air II. Separation of petroleum. III. Separation of water and alcohol

I

II

III

I and II

I,II and III

Fractional distillation is a process used to separate mixtures of liquids with different boiling points. In the given options, both the separation of components of liquid air and the separation of petroleum involve fractional distillation. In the separation of liquid air, the different components such as nitrogen, oxygen, and argon are separated based on their boiling points. Similarly, in the separation of petroleum, the different fractions such as gasoline, diesel, and kerosene are obtained through fractional distillation.

Explanation

Fractional distillation is a process used to separate mixtures of liquids with different boiling points. In the given options, both the separation of components of liquid air and the separation of petroleum involve fractional distillation. In the separation of liquid air, the different components such as nitrogen, oxygen, and argon are separated based on their boiling points. Similarly, in the separation of petroleum, the different fractions such as gasoline, diesel, and kerosene are obtained through fractional distillation.

10. Which of the following is not a chemical change?

Burning acetylene in welding torch

Rusting of Iron

Photosynthesis

Photosynthesis is not a chemical change because it is a process where plants convert sunlight, water, and carbon dioxide into glucose and oxygen using the energy from sunlight. It involves a series of complex biochemical reactions, but the substances involved (sunlight, water, carbon dioxide, glucose, and oxygen) remain the same throughout the process. No new substances are formed, and there is no rearrangement of atoms or molecules. Therefore, photosynthesis is a biological process rather than a chemical change.

Explanation

Photosynthesis is not a chemical change because it is a process where plants convert sunlight, water, and carbon dioxide into glucose and oxygen using the energy from sunlight. It involves a series of complex biochemical reactions, but the substances involved (sunlight, water, carbon dioxide, glucose, and oxygen) remain the same throughout the process. No new substances are formed, and there is no rearrangement of atoms or molecules. Therefore, photosynthesis is a biological process rather than a chemical change.