# Solutions

Lab Demonstration | Solution Preparation & Dilution.

Tip: This isn't the place to ask a question because the teacher can't reply.

## Key Questions

• A solution is when one thing (the solvent, usually a liquid) dissolves something else (the solute, usually a solid). An example of a solution is salt water, where water is the solvent and the sodium chloride is the solute.

"Solution" is another name for "homogeneous mixture", which is just a way of referring to a mixture in which the composition is exactly the same in every place. This is typically achieved when solvent molecules bind themselves to the solute, keeping them from sticking back together.

As I mentioned at the top, solutions are usually solid solutes and liquid solvents, but there are others as well. Air is an example of a solution where many different gases are present, and there are catalysts in which hydrogen gas is dissolved into a transition metal.

OK.

Why? Because there is usually a specific and measurable equilibrium between dissolved solute and undissolved solute at a given temperature.

#### Explanation:

Saturation defines an equilibrium condition: the rate of solute dissolution is equal to the rate of solute precipitation; alternatively, the rate of going up into solution is equal to the rate of coming out of solution.

$\text{undissolved solute "rightleftharpoons" dissolved solute}$

This saturation depends on temperature, the properties of the solvent, and the nature (the solubility of) the solute. A hot solution can normally hold more solute than a cold one. If this equilibrium condition is not reached, in the case of unsaturation, the solvent can dissolve more solute, but in the case of supersaturation, the solvent holds MORE solute than would be in equilibrium with undissolved solute.

Concentration can affect the rate of reaction.

#### Explanation:

Concentration is the amount of moles of a substance per unit volume. The more moles in a fixed volume, the higher the concentration.
This will have an affect on the rate of reaction. The higher the concentration the faster the rate of reaction, this is because there is an increased chance of a successful collision due to there being many more collisions.
Concentration of solutions can have an effect on reactions in equilibrium. According to Le Chatelier's principle, the system will oppose any change put upon it. So if we increase the concentration of a reactant, equilibrium will shift towards the product side to oppose the change.

I have a video on this as part of my A Level Chemistry Revision Videos if you are wanting any more information on this.

## Questions

• · Yesterday
• · 1 week ago
• · 1 month ago
• · 1 month ago
• · 1 month ago
• · 1 month ago
• 1 month ago
• 1 month ago
• · 1 month ago
• 1 month ago
• 1 month ago
• · 1 month ago
• · 1 month ago
• 1 month ago
• 2 months ago
• · 2 months ago
• · 2 months ago
• · 2 months ago
• · 3 months ago
• · 3 months ago
• · 3 months ago
• 4 months ago
• · 4 months ago