Sugar dissolved in water is an example of which solute-solvent combination?
a. liquid-solid
b. liquid-liquid
c. solid-liquid
d. gas-liquid
The correct answer and explanation is:
Correct Answer: c. solid-liquid
Explanation:
When sugar dissolves in water, it forms a solution where sugar is the solute and water is the solvent. A solute is the substance that is dissolved, and a solvent is the substance that does the dissolving.
In this case:
- Sugar (such as sucrose) is a solid at room temperature.
- Water is a liquid at room temperature.
Thus, this is an example of a solid-liquid solute-solvent combination.
Why and How Sugar Dissolves:
When sugar is added to water, the polar water molecules interact with the sugar molecules. Sugar molecules have many hydroxyl (–OH) groups, which are polar and can form hydrogen bonds with water. The water molecules surround the sugar molecules and pull them away from the solid crystal structure into individual molecules. This process is called dissolution.
Once the sugar molecules are dispersed evenly throughout the water, the mixture becomes a homogeneous solution. Because the sugar is distributed at the molecular level, the solution appears uniform throughout.
Other Types of Solute-Solvent Combinations:
| Solute | Solvent | Example |
|---|---|---|
| Solid | Liquid | Sugar in water (c) |
| Liquid | Liquid | Alcohol in water (e.g., vodka) |
| Gas | Liquid | Carbon dioxide in soda (d) |
| Liquid | Solid | Mercury in gold (amalgam) |
Understanding the solute-solvent relationship is crucial in chemistry and real-life applications such as cooking, pharmaceuticals, and environmental science. The solid-liquid combination is one of the most common and practical solution types we encounter daily.