Particulate Representations of Solutions
- A solution is an homogeneous mixture of two substances
- The components of a solution are a solute and a solvent
- The solvent is the component that is in the highest amount
- Liquids usually act as solvents in solutions
- The solute is the component that is in the least amount
- The solvent is the component that is in the highest amount
- E.g. A mixture of salt water is the best example for a solution. Salt is the solute and water acts as a solvent
- Any solution in which water acts as a solvent is called an aqueous solution
- Concentration makes reference to the amount of particles of solvent into an specific volume of solute
- The greater the amount of solute particles in a fixed volume, the greater the concentration
- A concentrated solution has a large amount of solute particles
- A diluted solution has a relatively small amount of solute
Exam Tip
Solutions are homogeneous mixtures, therefore the molecules of solute and solvent must be evenly spread in the container without forming regions. If individual regions of solute and solvent are formed, it is not a solution
Worked example
Which of the following samples of a salt + water solution has the highest concentration?
Answer:
The correct answer is C because:
- The particles of solute and solvent are evenly spread in the container
- It has a largest amount of solute particles (salt particles) compared to B which is also a solution
- A and D are not correct. The particles are forming individual regions of solute and solvent. Therefore, they are heterogenous mixtures which are not solutions
