ReviewSolutions: A ________________

________________ of substances.

• Mixture - ___________________________.

• _____________ – uniform ______________

and properties.

– Looks as if it’s one substance.

Solutions

*** ___________ + Solvent =____________***

Solute – the substance being _____________.

( smaller / larger amount)

_________ – the substance doing the dissolving.

( greater / lesser amount)

– ______________ = “universal solvent”

• Solutions Link (SMART Notebook)

• Eg. 1: NaCl in water (NaCl(aq)) dissolves

(therefore, it ( is / is not ) a solution)

Solute = ______________ Solvent = ____________

• Eg. 2: Sand in water ( does / does not) dissolve

(therefore, it is not a solution)

• Eg. 3: metal alloys (= metals mixed to form a solution):

Zinc + Copper Brass

(therefore, it ( is / is not ) a solution)

Rules for Dissolving

“Like ___________ Like”a.) Non-polar solvents dissolve _________________ solutes.

(What is Non-polar??)

Eg. Air (O2 + N2 +CO2 --- all are ( polar / non-polar );

therefore, is a solution)

b.) ______________ solvents dissolve polar solutes. (What is Polar???)

Eg. Water (H2O) + HF (drawing)

Rules for Dissolving

c.) ____________ solvents dissolve ionic compounds (M+N-).

(What is an Ionic compound???)

Examples for Dissolving

***Refer to Table F !!!***Eg.1: NaCl(aq) Na+

(aq) + Cl-(aq) Salt dissolving in water 1 (pt. 2)

(drawing)

Examples for Dissolving (Cont’d)

Eg.2: CaCl2(aq) Ca+2(aq) + Cl-

(aq) + Cl-(aq)

(drawing)

Eg.3: AgCl ???

Concentration**Review: What is a solution made up of?

Concentration: % of a solute in a solution

There are 3 Types of Concentration calculations covered:

1.) Mass % 2.) ppm 3.) Molarity (M)

Concentration (Cont’d)

1.) Mass % =

%100__

__x

SolutionofMass

SoluteofMass

Q: What makes up a solution?

Eg. What is the mass % of 10g of sucrose in 220g H2O?

Concentration (Cont’d)

2.) ppm (parts per million) = 000,000,1__

__x

SolutionofMass

SoluteofMass

Eg.1: How many ppm are 10g of sucrose in 80g of H2O?

Eg.2: A solution has a mass % of 6% O2. How many ppm of O2 are there?

Concentration (Cont’d)

3.) Molarity (M) =

SolutionofLiters

SoluteofMoles

__

__

** 1 L =______mL M = “molar”

** Remember Conversions of g moles; moles g **

Eg.1: What is the Molarity of a solution that contains 2 mol of KCl in 4 liters of solution?

Concentration (Cont’d)

Eg.2: What is the molarity of a solution that contains 30g of Sodium Hydroxide in 800ml of solution?

Eg.3: Which has a greater concentration of salt (NaCl) – a 2M solution or a 4M solution? Explain.

(Review Book, p.103, #’s 24-37 Homework!!!)

Standard Solutions

Standard Solutions: Solution of _____________ _____________

Volumetric Flask – instrument used to make

______________________.

Eg. How would you make 1,000ml of a 2 molar NaCl(aq)?

Step 1: (calculate . . . moles grams)

How many grams of NaCl do you need to make 1,000ml of a 2M NaCl(aq)?

Eg. How would you make 1,000ml of a 2 molar NaCl(aq)? (cont’d)

Steps 2-4: ( measure and combine ingredients)

** Salt (NaCl) goes into the flask First, and then water (H2O). **

(Step 2) Therefore, place ____g NaCl in 1,000ml _________________.

Eg. How would you make 1,000ml of a 2 molar NaCl(aq)? (cont’d)

(Step 3) Add a little _________________ to dissolve. (stir/mix)

(Step 4) Then, fill (with _______) to the ______ml mark. (stir/mix again)

End Result: ___M solution of NaCl ( = ___M NaCl(aq)).

(** Remember . . . Water is the “__________ solvent”; therefore, assume ___________ is the solvent in solutions we work with, unless otherwise indicated! **)

Eg.2: Describe (in Detail!) how you would make

100ml of a .5M KI(aq).

Diluting Solutions

Concentrated – A solution with a lot of solute in a given amount of solvent.

– Add more solute, or

– Remove some solvent (evaporate, etc).

Diluting Solutions (Cont’d)

Dilute – To make less concentrated (lower the concentration).

– Add more solvent (water).

Diluting Solutions (Cont’d)Dilute solution – A solution with very little solute in a given

amount of solvent.

Eg.1: How many moles of KCl are in 1L of a 2M KCl solution? (drawing)

Q.1: How can we dilute this solution to 1M?

Q.2: If we had 4L, would the solution be more or less dilute?___________

What would the new molarity (M) be?

Diluting Solutions (Cont’d)

Volume

molesM MVmoles

If . . . **

and . . .

** # of moles stays the same (like in dilutions) **

then . . .

** M1V1 = M2V2 Equation for Dilutions

**

M1 = initial molarity

V1 = initial volume

M2 = final molarity

V2 = final volume

Diluting Solutions (Cont’d)** M1V1 = M2V2 **

M1 = initial molarityV1 = initial volumeM2 = final molarityV2 = final volume

Eg.1: Calculate the concentration of the final solution when

20ml of a 6M HCl solution is diluted to 60ml.

Diluting Solutions (Cont’d)Eg.2: How much water must you add to 200ml of a 6M HCl

solution to decrease its concentration to 2M?

Eg.3: Review Book, p.107 #26-30.

Solubility

Solubility:– The amount of solute that can be dissolved in a

given amount of solvent at a particular temperature.

*** Table G – Solubility Curves ***

Solubility Curves (Table G)Eg. NH4Cl – Solubility of NH4Cl in 100g of H2O (Table G)

Temperature (◦C)

DissolvedSolute

Temperature(◦C)

DissolvedSolute

0 50

10 60

20 70

30 80

40 100

Solubility for . . .

Gases: increase temp. = decrease solubility

List the gases from Table G:

Solids: increase temp. = increase solubility

List the solids from Table G:

Solubility Questions (Table G)

Q.1: What is most soluble @ 40◦C?

A.) NaCl B.) KCl C.) KNO3 D.) NaNO3

Q.2: How many grams of KI could you dissolve in 50g of water @ 10◦C?

Q.3: How many g of Potassium Nitrate can you dissolve in 400g of H2O @ 60◦C?

Q.4: Which of the following is the least soluble in water @ 20◦C?

A.) NaNO3 B.) KCl C.) NaCl D.) KI

Terms associated with Solubility:

Saturated (“all desks in classroom taken”):

A solution that contains the _____________ amount of ___________

it can dissolve @ a particular _________________.

Terms associated with Solubility:

Unsaturated (“not all desks taken”):

Solution that contains ( less / more ) than the maximum amount of

_________ it can ____________ @ a given particular ____________.

Terms associated with Solubility:

Supersaturated (“more students than desks available”):

A solution that contains more than the maximum amount of solute it can dissolve @ a particular temperature.

**This is often achieved by saturating a solution @ a high temp., and then cooling down the solution.

Eg. Sodium thiosulfate (Demo. in class!)

Solubility

• *Diagram relating unsaturation, saturation, and supersaturation . . .

**Graph out solubility curve (from Table G) of NH4Cl.**

Label: unsaturated, saturated, and supersaturated.

Solubility QuestionsQ.1: SO2 @ 10◦C

a.) When is it unsaturated?b.) When is it saturated?c.) When is it supersaturated?

Q.2: 45g KNO3 in 100g H2O @ 30◦C?

A.) Unsaturated B.) Saturated C.) Supersaturated

Q.3: 80g NH4Cl in 100g H2O @ 90◦C?

A.) UnsaturatedB.) Saturated C.) Supersaturated

Q.4: ___ g of KCl is needed to saturate 200g H2O @ 50◦C?

Solubility is affected by . . .

1.) Temperature

A.) Solids: increase Temp. increase solubility (Direct)

B.) Gases: increase Temp. decrease solubility (Indirect)

2.) Pressure (Gases only!)

A.) Gases: increase Pressure increase solubility (Direct)

Q.: How do you keep CO2 in Coca-Cola???

Effect of Solutes on physical properties of Solvents:

A.) Boiling pt. (b.p.) Elevation

Water (a solvent!) is more attracted to dissolved particles (solute, such as NaCl) more IMF more energy needed to boil higher b.p.!

(diagram)

Eg. Water b.p. = 100◦C NaCl(aq) b.p = 105◦C

Effect of Solutes on physical properties of Solvents:

B.) Freezing pt. (f.p.) Depression

Solute (such as NaCl) added to Solvent (such as water) lowers freezing pt.!

Eg. Water f.p. = 0◦C NaCl(aq) f.p. = -15◦C

2 Factors which affect b.p. elevation and f.p. depression . . . 1.) Concentration:

a.) b.p. increase concentration increase b.p.

b.) f.p.increase concentration decrease f.p.

Eg. Which of the following will produce the lowest f.p.?

A.) 1M C6H12O6 C.) 4M C6H12O6

B.) 2M C6H12O6 D.) 3M C6H12O6

2 Factors which affect b.p. elevation and f.p. depression . . .

2.) # of particles produced in solution:

a.) b.p.increase # of particles increase b.p.

b.) f.p.increase # of particles decrease b.p.

Eg. Which of the following 2M solutions has the highest b.p.?

A.) C6H12O6 D.) (NH4)3PO4

B.) NaCl E.) C2H5OHC.) CaCl2 F.) NH3