Solutions Solubility, and concentration

Solution A solution is a homogeneous mixture that has the same composition, color, density and taste throughout. ie. they appear as ONE substance Examples: tap water Vinegar

Solution Cont… Solutions can also be gaseous, like the air you breathe, or even solid, like brass and sterling silver.

Making solutions: solutes and solvents When you mix two substances and they form a solution, you say that one substance dissolves in the other substance.

Solute Solvent The substance that dissolves (found in less amounts) Solutions have 2 parts: Solute The substance that dissolves (found in less amounts) Solvent The substance in which the solute dissolves (found in the greatest amounts)

Dissolving... To mix completely: the solute dissolves into the solvent.

There are three ways to speed up the dissolving process 1. Stirring 2. Increase surface area 3. Increase temperature

There are three ways to speed up the dissolving process Stirring –brings more solvent in contact with solute. Example: fruit drink with drink crystals. Stir the mixture to increase the rate of dissolving.

Demo Lets see if stirring will increase the dissolving rate of the solute.

There are three ways to speed up the dissolving process Increase surface area –breaking up a solid making it into a powder, provides more surface area.

Demo Lets see if increasing the surface area will increase the dissolving rate of the solute.

There are three ways to speed up the dissolving process Increase temperature- Increasing temperature speeds up particles causing them to bump each other and come in contact with the solvent.

Different states of solutes and solvents Solvents can be either: Solid, Liquid, Gas Solutes can be either: Solid, Liquid, Gas Solution Solute Solvent State of solute State of solvent Air Oxygen, carbon dioxide and other gases Nitrogen Gas Soda water Carbon dioxide Water Liquid Vinegar Acetic acid Filtered ocean water Sodium chloride (salt) and other minerals Solid Brass Zinc Copper antifreeze Alcohol water

Solute Solvent State Vinegar Air Soda Filtered sea water Brass Sugar water

Solute Solvent State Vinegar Air Soda Filtered sea water Brass Acetic Acid 5% Water 95% liquid Air Soda Filtered sea water Brass Sugar water

Solute Solvent State Vinegar Air Soda Filtered sea water Brass Acetic Acid 5% Water 95% liquid Air Oxygen 22% Nitrogen 78% gas Soda Filtered sea water Brass Sugar water

Solute Solvent State Vinegar Air Soda Filtered sea water Brass Acetic Acid 5% Water 95% liquid Air Oxygen 22% Nitrogen 78% gas Soda Carbon dioxide Water Filtered sea water Brass Sugar water

Solute Solvent State Vinegar Air Soda Filtered sea water Brass Acetic Acid 5% Water 95% liquid Air Oxygen 22% Nitrogen 78% gas Soda Carbon dioxide Water Filtered sea water Salt and other minerals Brass Sugar water

Solute Solvent State Vinegar Air Soda Filtered sea water Brass Acetic Acid 5% Water 95% liquid Air Oxygen 22% Nitrogen 78% gas Soda Carbon dioxide Water Filtered sea water Salt and other minerals Brass Zinc 35% Copper 65% solid Sugar water

Solute Solvent State Vinegar Air Soda Filtered sea water Brass Acetic Acid 5% Water 95% liquid Air Oxygen 22% Nitrogen 78% gas Soda Carbon dioxide Water Filtered sea water Salt and other minerals Brass Zinc 35% Copper 65% solid Sugar water Sugar 10% Water 90%

Soluble and insoluble

The solute is said to be soluble in that solvent. (ie. Solution) https://www.youtube.com/watch?v=khgOTDvG-4A If the particles of the solute are more attracted to the particles of the solvent. Dissolving occurs. The solute is said to be soluble in that solvent. (ie. Solution)

Dissolving does NOT occur. Insoluble If the particles of the solute are more attracted to their own particles than the solvent particles. Dissolving does NOT occur. The solute is said to be insoluble in that solvent. (ie. Mechanical)

Soluble or Insoluble? soluble insoluble

Soluble or Insoluble?

Soluble or Insoluble?

Concentration and solubility

Concentration and solubility Compare the two cups of tea… Concentrated solution Darker tea Large mass of dissolved solute for a certain quantity of solvent. Dilute solution Lighter tea Small mass of dissolved solute for a certain quantity of solvent

Concentration is… The percentage by volume of solute in solvent. Concentrated- large amount of solute in solvent. Dilute- small amount of solute in solvent.

A limit to concentration Make a salt solution: Add a spoonful… dissolved! Add a second spoonful… dissolved! Add a third, fourth and more… It becomes more concentrated! Eventually you reach a point where salt will NOT dissolve any more. Notice the lump of undissolved solid that is left on the spoon

Saturated vs. Unsaturated Will form when no more solute will dissolve at a certain temperature Unsaturated More solute is able to dissolve at a certain temperature

Which is dilute and which is more concentrated for each example? Orange juice from concentrate: ___________ Weak Kool-Aid: ____________________ Example 2: A solution with a concentration: 20g/100mL _______ A solution with a concentration: 25g/25mL_________ Example 3: A solution with a concentration: 20/80mL__________ A solution with a concentration: 20/100mL ________ Ex: 2 – dilute/concentrate Ex: 3 – concentrate/dilute

Time to think… Concentrated solutions can be: Adding more solute and keeping the amount of solvent the same. Keeping the amount of solute the same and reducing the amount of solvent. Example boiling off the water while making jam a solution could be considered “concentrated” and still be unsaturated.