1- Freezing of water is ____ change.
2- A solid which dissolve in water is called ____
1- Freezing of water is a physical change.
To understand why freezing of water is a physical change, we need to understand the concept of physical and chemical changes.
Physical changes, like freezing, do not alter the chemical composition of a substance. In the case of freezing water, the molecules slow down and come closer together, causing them to arrange in a regular and orderly pattern, forming a solid ice. Although the physical state of water changes from liquid to solid during freezing, the chemical makeup of water remains the same - H2O molecules.
To determine if a change is physical or chemical, consider if there is a change in chemical structure or composition. In the case of freezing, the water molecules do not undergo any chemical reaction. Hence, it is classified as a physical change.
2- A solid which dissolves in water is called a solute.
To understand why a solid that dissolves in water is called a solute, we need to understand the process of dissolution.
Dissolution is the process of a solid, liquid, or gas uniformly dispersing in a solvent to form a homogeneous mixture, known as a solution. In the context of water as a solvent, the solid that is being dissolved is referred to as a solute. The solute particles disperse and mix evenly with the water molecules, resulting in a solution.
For example, when table salt (sodium chloride) is added to water, the salt particles break apart and mix evenly throughout the water. In this case, salt is the solute, and water is the solvent. The resulting mixture is a solution of saltwater.
So, when a solid dissolves in water, it is called a solute because it undergoes dissolution and becomes uniformly dispersed in the solvent.