A solution is a mixture of one substance dissolved in another so the properties are the same throughout. A solution is composed of a solute and the solvent. The solute is the substance being dissolved and the solvent is the part of the solution that does the dissolving. The solute is of molecular size.
Examples of Solutions:
* Two liquids that are soluble are said to be miscible in one another.
Strength of Solutions
The solubility is the amount of solute that be be dissolved in a given amount of solvent at any one temperature. A solution is said to be unsaturated as long as more solute can be dissolved.
Dilute or Weak Solution - only a small amount of solute compared to solvent.
Concentrated Solution - A relatively large amount of solute to solvent.
Saturated Solution --At this point, the concentration of the solute in solution is the maximum possible under the existing conditions (temperature and pressure). A solution is saturated when no more solute can be dissolved at the current temperature. A saturated solution is one in which the dissolved and undissolved solutes are in equilibrium.
Supersaturated Solution -- a solution that contains more dissolved substance than does a saturated solution; the solution is not in equilibrium with the pure substance. Examples of supersaturated solutions are carbonated water,
Water is the Universal Solvent
Although water is sometimes called the universal solvent, there are many things it cannot dissolve. For example water and oil do not mix. We say oil is immiscible in water.
What makes water such a good solvent?
Water is a good solvent due to its polarity. The solvent properties of water are vital in biology, because many biochemical reactions take place only within aqueous solutions
When an ionic or polar compound enters water, it is surrounded by water molecules. The relatively small size of water molecules typically allows many water molecules to surround one molecule of solute. The partially negative dipoles of the water are attracted to positively charged components of the solute, and vice versa for the positive dipoles. For more on this topic see: Why is water such a good solvent?
Assessment Questions:Multiple Choice Questions
Solutions: What are solutions, examples of solutions, strength of solutions, what is the universal solvent?
Suspensions, emulsions, colloids: What are suspensions, emulsions and colloids. Examples of colloids.
Hyrocolloids: Hydrocolloid have colloid particles spread throughout water, and depending on the quantity of water available can take place in different states
Hydrocolloids in Cooking: What are Polysaccharides? Xanthan Gum Guar Gum vs. Locust Bean Gum Agar Molecular Properties in Cooking Pectin Science of Culinary Foams Food Thickening Agents How to make smoother ice cream
Summary Sheet: Definitions for work, energy and power. Types of energy, calculating work, and power. Examples of work and power. Work-Energy Principle.
Assessment Test: Great page for gifted and talented students! Some excellent challenging problems.