PM2 Review Questions 2023

Front

What factors impact the rate of dissolving a solid in water?

Back

The rate of dissolving a solid in water is impacted by temperature of the water, stirring the solid, and the particle size of the solid. Air pressure has the least impact.

Front

Why does smaller particle size of sugar dissolve faster in water?

Back

Smaller particle size increases the surface area of the sugar, allowing it to interact more with the water molecules, leading to faster dissolution.

Front

What is a reversible physical change?

Back

A reversible physical change is a change that can be undone, returning the substance to its original state, such as melting and freezing.

Front

What happens when salt is added to water?

Back

Adding salt to water increases the density of the water, allowing objects like eggs to float.

Front

What is the definition of density?

Back

Density is the mass of a substance divided by its volume, often expressed in grams per cubic centimeter (g/cm³).

Front

How does temperature affect the solubility of solids in liquids?

Back

Generally, increasing the temperature of a liquid increases the solubility of solids, allowing more of the solid to dissolve.

Front

What is the role of stirring in the dissolving process?

Back

Stirring helps distribute the solid particles throughout the liquid, increasing contact with the solvent and speeding up the dissolving process.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change alters the form or appearance of a substance without changing its composition, while a chemical change results in the formation of new substances.

Front

What is solubility?

Back

Solubility is the ability of a substance to dissolve in a solvent at a given temperature and pressure.

Front

What is an example of a reversible physical change?

Back

An example of a reversible physical change is the melting of ice into water, which can be frozen back into ice.