topics to be covered 1. what are solutions? 2. · pdf fileobjective: measuring solubility. 3....

TOPICS TO BE COVERED

1. WHAT ARE SOLUTIONS?

2. SOLVENTS AND SOLUTES

3. SOLUBILITY AND ITS FACTORS

4. CONCENTRATIONS

5. SOLUTION STOICHIOMETRY

6. COLLIGATIVE PROPERTIES

SOLUTIONSCHEMICALS + WATER

1. WHAT ARE SOLUTIONSOBJECTIVE: WHAT ARE THEY?

SOLUTIONS

• IMPORTANCE OF STUDYING SOLUTIONS

• BECAUSE MANY REACTIONS TAKE PLACE IN

SOLUTIONS

• BECAUSE MIXING REACTANTS IN SOLID FORM

OFTEN DO NOT RESULT IN REACTIONS.

• REACTIONS REQUIRE COLLISIONS AT THE

ATOMIC/MOLECULAR LEVEL, AND IN THE

SOLID STATE, THIS DOES NOT OCCUR AT

A SIGNIFICANT RATE.

1. WHAT ARE SOLUTIONS?

SOLUTIONS ARE…

HOMOGENOUS MIXTURES

• HOMOGENOUS VS. HETEROGENEOUS

• MIXTURE VS. COMPOUND

1. WHAT ARE SOLUTIONS

Does not always involve liquids


SOLVENT- PRESENT IN GREATER AMOUNT

- DOES THE “DISSOLVING”

WATER IS THE UNIVERSAL

SOLVENT

SOLUTE- PRESENT IN LESSER AMOUNT

- IS THE ONE “DISSOLVED”


IF A SOLUTION IS A MIXTURE, DO

THE SOLUTES AND THE SOLVENTS

CHEMICALLY REACT

OR PHYSICALLY MIX?

2. SOLUBILITYOBJECTIVE: IF SOMETHING DOES OR DOES NOT DISSOLVE

2. SOLUBILITY

Why do some things dissolve

while others do not?

What does it mean for something

to “dissolve?”

2. SOLUBILITY

What does it mean for

something to “dissolve?”

dissociation

2. SOLUBILITY

Why do some things dissolve

while others do not?

“Like dissolves Like”

2. SOLUBILITY

“Like dissolves Like”

Polar Solvent will dissolve…

Non-Polar Solvent will dissolve

2. SOLUBILITY

Miscible vs. Immiscible

Miscible = dissolves

Immiscible = does NOT dissolve

2. SOLUBILITY

How much of some thing can be

dissolved?

SolubilityTHE MAXIMUM AMOUNT OF A SOLUTE THAT CAN DISSOLVE

AT A SPECIFIED TEMPERATURE AND PRESSURE

2. SOLUBILITY

Increasing/Decreasing Solubility

1. Temperature

2. Pressure

SO AS

TEMPERATURE

_______,

SOLUBILITY

______

2. SOLUBILITY

Increasing/Decreasing

Solubility

with Temperature

Unsaturated Solutions

more solute can be

dissolved

no heat necessary

Saturated Solutions

no more solute can

be

dissolvedno heat necessary

Super-Saturated

Solutions

more solute than

normal

heat necessary

Super-Saturated

Solutions

Rock Candy

SOLUBILITY OF GASES

AS TEMPERATURE _____ THE

SOLUBILITY OF GAS _______.

SO TEMPERATURE AND SOLUBILITY

OF A GAS HAVE A(N) ____.

RECALLING HEAT AS KINETIC

ENERGY, WE CAN EXPLAIN THIS

BY…

SOLUBILITY OF SOLIDS

SOLUBILITY OF GASES

SUMMARY & REVIEW

1. EXPLAIN WHY THERE MIGHT BE MORE MINERAL FORMATION

SURROUNDING THERMAL SPRINGS THAN COOL MOUNTAIN

SPRINGS.

2. WHY DOES WARM SODA “FLATTEN” QUICKER THAN COLD

SODA?

3. CONCENTRATIONSOBJECTIVE: MEASURING SOLUBILITY

3. CONCENTRATIONS

concentration =

how much solute in the solution

2 methods

3. CONCENTRATIONS

Molarity MOLALITY

Symbol

Formula

Units

Example

3. CONCENTRATIONS

Molarity MOLALITY

Symbol M

Formula M = mol

L

Units mol = mol of SOLUTE

L = liters of solution

Example 5 M, or 5 molar

3. CONCENTRATIONS

1.23 mol of HCl in solution

With volume of 5.00 L.

What is molartiy?

3. CONCENTRATIONS

3.45 M solution of AgCl is

made with 2. 45 mol of AgCl.

What is volume?

3. CONCENTRATIONS

3.45 M solution of AgCl is

made with 2.45 L.

What is mol of AgCl?

3. CONCENTRATIONS

Precipitate = a solid that forms

3. CONCENTRATIONS

0.125 L of 0.100 M HCl is

added to Zn. What mass of

ZnCl2 is formed?

Zn + 2HCl → ZnCl2 + H2

3. CONCENTRATIONS

11.0 g of Cu are needed. What

volume of a 0.500 M solution of

CuSO4 is needed to result in 11.0 g

of copper?

CuSO4+ Fe Cu + FeSO4

Ba(NO3)2(aq) + Na2SO4(aq) Ba(SO4)(s) + 2NaNO3(aq)

25mL of 0.5M Ba(NO3)2 solution is

combined with excess Na2SO4. How

many grams of precipitate formed?

Pb(NO3)2(aq) + 2NaCl(aq) PbCl2(s) + 2NaNO3(aq)

• How many grams of precipitate would form if

30mL of a 0.25M Pb(NO3)2 solution was added to

20mL of a 0.50M NaCl solution?

• How many moles of the excess reactant are left

over after the reaction?

• What is the molarity of the excess reactant after

the reaction?

CaCl2(aq) + 2NH4OH(aq) Ca(OH)2(s) + 2NH4Cl(aq)

What volume of a 0.2M NH4OH solution

would be required to precipitate all of the

Ca2+ ions in 50mL of a 0.15M CaCl2

solution?

• SOLUBILITY OF GASES

• HENRY’S LAW

• IF THE SOLUBILITY OF A GAS IN WATER IS

0.77G/L AT 350KPA OF PRESSURE, WHAT

IS ITS SOLUBILITY, IN UNITS OF

GRAMS/LITER, AT 100KPA?

• SOLUBILITY OF GASES

• HENRY’S LAW

• A GAS HAS A SOLUBILITY OF 3.6G/L AT A

PRESSURE OF 100KPA. WHAT PRESSURE IS

NEEDED TO PRODUCE AN AQUEOUS

SOLUTION CONTAINING 9.5G/L OF THE

SAME GAS?

• THE SOLUBILITY OF METHANE IN WATER AT

100KPA IS 0.026G/L, WHAT WILL THE

SOLUBILITY BE AT A PRESSURE OF 180KPA?

• SOLUBILITY OF LIQUIDS

• LIKE DISSOLVES LIKE

• MISCIBLE

• NON-POLAR AND NON-POLAR =

MISCIBLE

• POLAR + POLAR = MISCIBLE

• IMMISCIBLE

• PERCENT SOLUTIONS

• SIMILAR TO PPM

• PERCENT SOLUTIONS

• WHAT IS THE PERCENT BY VOLUME OF

ETHANOL (C2H6O) WHEN 75ML OF ETHANOL

IS DILUTED TO A VOLUME OF 250ML WITH

WATER?

• A SOLUTION CONTAINS 2.7G OF CUSO4 IN

75ML OF SOLUTION. WHAT IS THE PERCENT

BY MASS OF THE SOLUTION?

• CONCENTRATION OF IONS

• CALCULATE THE NUMBER OF MOLES OF CL- IN

2.75 L OF 1.0X10-3M ZNCL2

• HOW MANY GRAMS OF SULFATE ION ARE

PRESENT IN 500ML OF A 2M AL2(SO4)3

SOLUTION?

5. COLLIGATIVE PROPERTIESOBJECTIVE: HOW ADDING THINGS TO WATER

CHANGES WATER


MAIN IDEA:

The properties of a solution are different

from those of a pure solvent.

When you add things, like solutes, to

water, it changes the properties of

the water!

SOME OF THESE DIFFERENCES ARE DUE TO THE

PRESENCE OF SOLUTE PARTICLES IN THE

SOLUTION.


COLLIGATIVE PROPERTIES =

A PROPERTY OF A SOLUTION THAT

DEPENDS ON THE

CONCENTRATION OF THE SOLUTE

PARTICLES.


COLLIGATIVE PROPERTIES =

1. Increases boiling temperature

2. Lowers freezing temperature

• COLLIGATIVE PROPERTIES

• COLLIGATIVE PROPERTIES – A PROPERTY OF A

SOLUTION THAT DEPENDS ON THE

CONCENTRATION OF THE SOLUTE PARTICLES.

• THE WORD COLLIGATIVE IS DERIVED FROM THE

LATIN COLLIGATUS MEANING BOUND

TOGETHER, SINCE THESE PROPERTIES ARE BOUND

TOGETHER BY THE FACT THAT THEY ALL DEPEND

ON THE NUMBER OF SOLUTE PARTICLES.


• BOILING POINT ELEVATION – THE DIFFERENCE IN

TEMPERATURE BETWEEN THE BOILING POINTS OF

A SOLUTION AND OF THE PURE SOLVENT.

• FREEZING POINT DEPRESSION – IS THE

DIFFERENCE IN TEMPERATURE BETWEEN THE

FREEZING POINTS OF A SOLUTION AND OF THE

PURE SOLVENT.

4. CONCENTRATION

Molarity MOLALITY

Symbol

Formula

Units

Example

4. CONCENTRATIONMolarity MOLALITY

Symbol M m

Formula M = mol

L

m = mol

kg

Units mol = mol of SOLUTE

L = liters of solution

mol = mol of SOLUTE

kg = kilograms of

SOLVENT

Example 5 M, or 5 molar 5 m, or 5 molal


How many grams of KI must be

dissolved in 0.500 g of water to

produce a 0.060 molal KI

solution?

5. COLLIGATIVE PROPERTIES1. Determine the molality of a solution of 560 g acetone, C3H6O in 0.620 kg of water.

2. What is the molality of a solution of 12.9 g of fructose, C6H12O6, in 31 g of water?

3. Determine the molal concentration of 71.5 g of linoleic acid, C18H32O2, dissolved in

525 g of C6H14.

4. How many moles of butanol, C4H10O must be dissolved in 0.125 kg of ethanol in

order to produce a 12.0 m solution?

5. Convert the answer above to grams!

6. What mass of urea, NH2CONH2, must be dissolved in 2250 g of water to make a

1.50 molal solution?

7. What mass of CaCl2 must be dissolved in 590.0 g of water to produce 0.82 molal

solution?


• THE MAGNITUDE OF BP ELEVATION AND FP

DEPRESSIONS IS PROPORTIONAL TO THE

NUMBER OF SOLUTE PARTICLES DISSOLVED IN

THE SOLVENT.


• WOULD A DILUTE OR CONCENTRATED SODIUM

FLUORIDE SOLUTION HAVE A HIGHER BOILING

POINT?

• IF EQUAL NUMBER OF MOLES OF KI AND MGF2

ARE DISSOLVED IN EQUAL AMOUNTS OF WATER,

WHICH SOLUTION WOULD HAVE THE HIGHEST:

• BOILING POINT

• FREEZING POINT

MOLARITY MOLALITY

• VOLUME OF SOLUTE +

• VOLUME OF SOLVENT

• UNIT = M

BOTH MOLARITY AND MOLALITY MEASURE

CONCENTRATION

• MASS OF SOLVENT

IN KILOGRAMS

• UNIT = M

(ITALICIZED)

• CALCULATING MOLALITY

• CALCULATE THE MOLALITY AND TOTAL MOLALITY

(IF APPLICABLE) OF A SOLUTION PREPARED BY

DISSOLIVING 10.0G OF NACL IN 600 G OF

WATER.

• CALCULATE THE MOLALITY AND TOTAL MOLALITY

(IF APPLICABLE) OF A SOLUTION PREPARED BY

DISSOLIVING 10.0G C12H22O11 OF IN 600 G OF

WATER.


• HOW MANY GRAMS OF POTASSIUM IODIDE

MUST BE DISSOLVED IN 0.500 G OF WATER

TO PRODUCE A 0.060 MOLAL KI SOLUTION?


• WHAT IS THE DIFFERENCE BETWEEN A 1M

AND A 1M SOLUTION?

• A 4 G SUGAR CUBE (C12H22O11) IS DISSOLVED IN A

350 ML TEACUP OF 80 °C WATER. WHAT IS THE

MOLALITY OF THE SUGAR SOLUTION IF THE DENSITY

OF WATER AT 80° = 0.975 G/ML

• CALCULATING BP AND FP CHANGES

• BP

•ΔTB = KB * M

• FP

•ΔTF = KF * M


• KB, KF = THE MOLAL BP/FP CONSTANT, WHICH IS

EQUAL TO THE CHANGE IN BP/FP TEMPERATURE FOR

A 1 MOLAL SOLUTION.


• WHAT IS THE BOILING POINT OF A 1.5 MOL

SOLUTION THAT IN 800G OF WATER?


• WHAT IS THE BOILING POINT OF A 1.2 MOL

SOLUTION OF NACL IN 800G OF WATER?


• WHAT IS THE BP AND FP OF A 1.40 MOL SOLUTION

OF NA2SO4 IN 1750G OF WATER?

• DETERMINING MOLAR MASS FROM ΔTB AND ΔTF

• MOLAR MASS =

• 7.5 G OF SOLUTE IS ADDED TO 22.60 G OF

WATER. THE WATER BOILS AT 100.78 DEGREES C.

WHAT IS THE MOLAR MASS OF THE SOLUTE?

• DETERMINING MOLAR MASS FROM ΔTB AND ΔTF

• WHAT INFORMATION/MEASUREMENTS ARE

NEEDED TO FIND THE MOLAR MASS OF A

SOLUTE WHEN GIVEN THE BOILING POINT

ELEVATION, ΔTB, FOR AN AQUEOUS

SOLUTION?

topics to be covered 1. what are solutions? 2. · pdf fileobjective: measuring solubility. 3....

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