1. Solutions

3. Question of the Day What are the 3 states of matter?
Draw what each looks like in terms of how close or far apart the particles of matter are positioned

4. Review: States of Matter

5. What about plasma? (Enrichment)

7. Review: Mixtures
A mixture is a substance made up of two or more substances which are physically combined.
A mixture can be heterogeneous or homogeneous
Examples:

8. Review: Heterogeneous Mixtures
A heterogeneous mixture is a mixture where we can distinguish (see or identify) the different parts that make up the total mixture

9. Review: Homogeneous Mixture (Solutions)
A homogeneous mixture is a mixture where we cannot distinguish (see or identify) the different parts that make up the total mixture. A homogenous mixture is also called a solution.

10. Solutions A solution is a homogeneous mixture
A solution contains a solute and a solvent
Solute: what is being dissolved
Solvent: what is present in the greatest amount

11. Dissolution looks like…

12. Comparing Solutions Suppose I add some sugar into 3 different glasses…
Which one will taste the sweetest? Why?

13. Comparing Solutions Continued…
Now suppose each glass has 1 teaspoon of sugar but different amounts of water
Which is the sweetest?

14. Concentration Concentration = 𝑎𝑚𝑜𝑢𝑛𝑡 𝑜𝑓 𝑠𝑜𝑙𝑢𝑡𝑒 𝑎𝑚𝑜𝑢𝑛𝑡 𝑜𝑓 𝑠𝑜𝑙𝑣𝑒𝑛𝑡
𝑐 ( 𝑔 𝐿 )= 𝑚 (𝑔) 𝑣 (𝐿) for the sugar/water example
But a concentration can also be liquid-liquid, gas-liquid, etc.
𝑐 ( 𝑚𝐿 𝐿 )= 𝑣 (𝑚𝐿) 𝑣 (𝐿) for food colouring/water
𝑐 ( 𝐿 𝐿 )= 𝑚 (𝐿) 𝑣 (𝐿) for the oxygen gas in air (nitrogen gas)

15. Dimensional Analysis AKA converting between different values
3 500mL in L?
sec in weeks?
15 kg of water in L?

16. Concentration Example
Which will taste more sugary?

18. Concentration % Notation
Concentrations are sometimes given as a percentage
When no other information is given, it is implied that the percentage means:
% = # 𝑜𝑓 𝑔𝑟𝑎𝑚𝑠 𝑝𝑒𝑟 100 𝑚𝑙 𝑜𝑓 𝑠𝑜𝑙𝑣𝑒𝑛𝑡
E.g. 25% = 25 𝑔 100 𝑚𝐿
In other cases, you may encounter
% mass/mass
% volume/volume

19. Comparing Concentrations Example 2
Rank the following concentrations from lowest to highest
50g/1250ml
75% mass by volume
0.5kg/1.5L

20. Concentrations Example 3
Suppose I add 250 ml of orange juice to 450 ml of grapefruit juice. What is the total concentration of orange juice?

21. Making Iced Tea
Why do we start with hot tea?

22. Solubility
The solubility of a substance is a fundamental property. It is a measure of how much solute can be dissolved into a liquid (usually water)
For a solid solute, increasing the temperature of the solution will increase its solubility
However, for a dissolved gas, increasing the temperature decreases its solubility
E.g. Soda will go flat faster if it’s warm versus when it is cold
Due to particle agitation allowing for gas to escape
If a substance cannot be dissolved, it is insoluble

23. Dilutions
Sometimes, a solution can be too concentrated. We reduce the overall concentration of a solution by diluting it
The usual way to achieve this is to simply add more solvent
Sometimes, we can take a sample (aliquot) and then add more solvent

24. 𝐶 1 𝑉 1 = 𝐶 2 𝑉 2 Formula For Dilutions Where:
𝐶 1 𝑉 1 = 𝐶 2 𝑉 2
Where:
C1 = concentration of original (initial) solution
C2 = concentration of final solution
V1 = initial volume
V2 = final total solution
Remember the formula, but especially know how to use and apply it
Technically this formula applies for making something more concentrated too

25. Dilution Example
Suppose I have 5g of salt in 100mL of water. If I dilute the solution to 25ml, what will the new concentration be?

26. Dilution Example 2
If I have a 500ml of a 25% sugar solution, how much water will I need to add in order to get a 15% sugar solution?

27. Dilution Example 3
After dilution, my iced tea mixture now has a concentration of 36g/L. Suppose my initial volume was 250 ml and my final volume was 1200 ml, what was the initial concentration?

28. Last Word
When I am dissolving a solute or diluting a solution, what kind of change is this?