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Properties, Concentrations, and Dilutions CHAPTER 16: SOLUTIONS

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Page 1: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Properties, Concentrations, and Dilutions

CHAPTER 16: SOLUTIONS

Page 2: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Solute and Solvent

Solute is the substance being dissolved.

Solvent is the substance doing the dissolving.

Example: Salt and Water. We dissolve salt in water.

Therefore, the salt is the solute and the water is the solvent.

Why is water called the universal solvent?

REVIEW

Page 3: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Forming a Solution• The composition (what they are made out of) of the

solvent and solute determine whether a substance will dissolve.

How FAST will the substance dissolve?• This depends on three things:• 1. Stirring: Increase of decrease rate?• 2. Temperature: Increase or decrease rate?• 3. Particle Size: The more surface area exposed, the

faster it will dissolve.

PART 1: PROPERTIES OF SOLUTIONS

Page 4: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

What amount of a substance will dissolve?

Particles move from a solid into a solution. But how much can be dissolved?

Solubility describes the amount of substance that can be dissolved by a certain quantity of a solvent at a certain temp and pressure until the

solution becomes saturated.

PART 2: SOLUBILITY

Page 5: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Different Types of Solutions:

• Saturated Solution: The maximum amount of solute that can be dissolved at a specific temp and pressure.

• Unsaturated Solution: A solution that contains less solute than required to be a saturated solution and a certain temp and pressure.

• Supersaturated Solution: contains more solute than it can theoretically hold at a given temperature.

• Miscible Solution: when two liquids will dissolve into one another. There is no separation.

• Immiscible: liquids that are not soluble in each other. You can tell if it is immiscible by observing layers.

SOLUBILITY

Page 6: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

SOLUBILITY

Miscible Immiscible

Oil and Water

Water and Acetone

Page 7: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

SOLUTIONS

Supersaturated Solution

Page 8: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Learn how to make your own rock candy using Chemistry at home.

(AKA Crystal Meth… Not really. Just kidding.)

GOOD NEWS: BREAKING BAD FANS

http://video.about.com/chemistry/How-to-Make-Rock-Candy.htm

Page 9: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

What do YOU think?What type of solution is being utilized?

How are they making that solution?

ROCK CANDY EXPLAINED

Page 10: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

• 1. Temperature: Solubility of MOST substances increases as temperature increases.

• You can dissolve more solute in the solvent as you increase the temperature. Think about how we made our rock candy.

• EXCEPTION: Gas solubility increases as temperature decreases.

FACTORS THAT AFFECT SOLUBILITY

Page 11: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

• 2. Pressure: Changes in pressure doesn’t affect the solubility of solids and liquids, but it greatly influences the solubility of gases.

• As pressure increases, the solubility of gases also increases. Use Henry’s Law for calculations.

• S = solubility• P = pressure• Directly Proportional

FACTORS THAT AFFECT SOLUBILITY

Page 12: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

How would I describe solubility in terms of UNITS?

Solubility is usually expressed in grams of solute per 100g of solvent.

• Example: 36g of sodium chloride in 100g of water at 25 degC.

• Examples in terms of saturation: If 36g of NaCl is added to 100g water, it will dissolve completely, but if I added 1 more gram of NaCl, only 0.2g of that will dissolve. Therefore, 36.2g of NaCl in 100g of water is a SATURATED solution.

• How would I make it super saturated??

SOLUBILITY OF SOLUTIONS

Page 13: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Concentration: a measure of the amount of solute that is dissolved in a given quantity of solvent.

Dilute Solution: a weak concentration. Contains small amount of solute.

Concentrated Solution: strong concentration. Contains a large amount of solute.

PART 3: CONCENTRATIONS

DiluteConcentrated

Page 14: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

MOLARITY

Moles of solute dissolved in 1 Liter of solution.

CONCENTRATIONS

Page 15: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

LET’S MAKE A SOLUTION

Let’s determine the molarity of a solution that we

make. Let’s start with 10

grams of sodium chloride and

add it to a 1-L volumetric flask half filled with distilled water.

Page 16: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

LETS MAKE A SOLUTION

Swirl the flask carefully to dissolve the solute.

Page 17: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

LETS MAKE A SOLUTION

Fill the flask with water exactly to the 1-L mark.

What is the concentration of the solution in molarity?

Page 18: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Answer: 0.171M

Page 19: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

This will work with ANY volumetric flask. Big or small. We can then calculate the molarity

(concentration) of our solution.

LETS MAKE A SOLUTION

• How do we convert mL to L?

Page 20: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Find the number of moles of solute in a solution…

WHAT IF YOU KNOW THE MOLARITY?

• We can also convert moles to grams.

Page 21: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Diluting a solution reduces the number of moles per unit volume. The number of moles of solute remains unchanged.

Dilution equation:

DILUTIONS

Page 22: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

DILUTIONS

To prepare 100 ml of MgSO4 from a stock solution of 0.171M NaCl, a student first measures 10 mL of the stock solution with a 10-mL pipet.

Page 23: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

DILUTIONS

She then transfers the 10 mL to a 100-mL volumetric flask.

Page 24: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

DILUTIONS

Finally, she carefully adds water to the mark to make 100 mL of solution. What is the final concentration?

Page 25: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Use M1 x V1 = M2 x V2

Answer: 0.0171

Page 26: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Some volume measuring devices…

BuretGraduated Cylinder

Volumetric FlaskGlass Pipets

TO MEASURE VOLUME

Page 27: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

DILUTION CALCULATION

Page 28: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

These are not as common as molarity, but are used sometimes.

Percent by volume:

Percent by mass:

PERCENT CONCENTRATIONS OF SOLUTIONS

Page 29: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Percent by volume: (volume/volume)

PERCENT CONCENTRATION CALCULATIONS

Page 30: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Percent by mass: (mass/mass)• Suppose you want to make a 2000g

solution that has a 2.8% (m/m) concentration of glucose in water.

• How many grams of glucose should you use?

PERCENT CONCENTRATION CALCULATIONS

Page 31: Properties, Concentrations, and Dilutions. Solute and Solvent Solute is the substance being dissolved. Solvent is the substance doing the dissolving

Page 499# 42, 44, 46, 48, 49a, 51, 52, 53a,b, 54a,

55a

CLASS WORK