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

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.

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.

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.

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.

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.

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.

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.

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.

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.