Chapter 6: Sports Drink

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Chapter 6 Sports Drink
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Sports Drinks

• This chapter will introduce the chemistry needed
  to understand how Sports Drinks work
• Section 6.1 Solutions electrolytes
• Section 6.2 Concentrations of solutions
• Section 6.3 Acidity pH
• Section 6.4 Solubility precipitates
• Section 6.5 Stoichiometry
• Section 6.7 Limiting Reactants
• Section 6.6 Properties of solutions

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Section 6.1Solutions Electrolytes
What are those electrolytes they say youre
replacing by drinking sports drinks?
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Dissolving substances

• Substances are dissolved by a process called
  hydration when the solvent is water
• The solvent and solute need to break
  intermolecular forces within themselves- This
  requires ENERGY (ENDOTHERMIC)
• New intermolecular forces are formed between the
  solvent and solute.- This releases
  ENERGY(EXOTHERMIC)
• The solvent carries off the solute particles

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Solution Formation
Endothermic
Exothermic
Endothermic
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Dissolving Ionic Compounds
-

Solute,Ionic compound
Solvent,water
Water molecules are polar and they are attracted
to the charges of the ions in an ionic compound.

-
When the intermolecular forces are stronger
between the water and the ion than the
intramolecular forces between the ions, the water
carries away the ion.
-



-
-
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Dissolving Ionic Compounds
-

Ionic compound
water
As more ions are exposed to the water after the
outer ions were carried off, more ions can be
carried off as well.
-
-


-
-
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Dissolving Ionic Compounds
-

Ionic compound
water













-

These free-floating ions in the solution allow
electricity to be conducted













-







-







-
-


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Electrolytes

• When there are free-floating charges in a
  solution then it can conduct electricity.
• Things that produce free-floating charges when
  dissolved in water are called electrolytes.

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Dissolving Covalent Compounds
Polar covalent molecules are formed in the same
waywater forms intermolecular forces with the
solute and carries the solute particles away.
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Dissolving Covalent Compounds
However, the polar covalent molecules stay
together and just separates from other solute
molecules. NO charged ions form.
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Non-electrolytes

• When molecules separate from other molecules, but
  free-floating charges are not produced, the
  solution cannot conduct electricity.
• These are called
• non-electrolytes

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Types of Electrolytes
Strong Electrolytes
Non-Electrolytes
Weak Electrolytes
Soluble Ionic compounds Strong Acids Bases
Covalent Compounds except for ACIDS
Insoluble Ionic Compounds Weak Acids Bases
Almost all ions are separated when dissolved in
water.
No molecules separateions are not formed
Only a few ions are separated when dissolved in
water
Does not conduct electricity at all when
dissolved in water
Easily conducts electricity when dissolved in
water
Conducts electricity slightly when dissolved in
water
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Breaking up Electrolytes

• Leave polyatomic ions in-tact (including the
  subscript within the polyatomic ion)
• All subscripts not within a polyatomic ion become
  coefficients
• Be sure to include charges on the dissociated
  ions!

Example Break up the following ionic compounds
into their ions
KNO3 Ca(NO3)2 Na2CO3
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Breaking up Electrolytes

• Leave polyatomic ions in-tact (including the
  subscript within the polyatomic ion)
• All subscripts not within a polyatomic ion become
  coefficients
• Be sure to include charges on the dissociated
  ions!

Example Break up the following ionic compounds
into their ions
? K1 NO3-1 ? Ca2 2 NO3-1 ? 2 Na1 CO3-2
KNO3 Ca(NO3)2 Na2CO3
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Misconceptions about dissolving

• People often describe something that dissolves as
  having disappeared
• Before the solute dissolves, its in such a large
  group of particles that we can see it.
• After dissolving, the solute particles are still
  theretheyre just spread out throughout the
  solution and are in groupings so small that our
  eyes cant see them

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Types of Solutions
A solution is made of two parts SOLUTE the
substance that is dissolved usually in
minority SOLVENT The substance that does the
dissolving, usually in majority

GAS-LIQUID
SOLID-LIQUID
LIQUID-SOLID
Salt Water
SODA (Carbon dioxide gas in water)
Dental Filling (Mercury in Silver)
When 2 substances dissolve in one another, they
are considered SOLUBLE If they cannot dissolve in
one another, they are INSOLUBLE
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Types of Solutions

LIQUID-LIQUID
GAS-GAS
SOLID-SOLID
Alcohol water Acetic acid in water(vinegar)
AIR (Oxygen in Nitrogen gas)
ALLOYS (brass, bronze, sterling silver, steel)
When 2 liquids dissolve in one another, they are
considered MISCIBLE If they cannot dissolve in
one another, they are IMMISCIBLE.
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Types of Solutions
Unsaturated
Super-Saturated
Saturated
Has more solute dissolved than a saturated
solution has at room temperature No visual- need
some background information
Not full- we can add solute to the solvent it
will dissolve Visual-no solid on bottom
Its Full- no more solute can be
dissolved Visual- solid can be seen at the bottom
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Diagrams of Unsaturated,Saturated,
SuperSaturated Solutions
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Diagrams of Unsaturated vs Saturated Solutions
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A SUPERSATURATED SOLUTION
A supersaturated solution can be seeded. This is
a solution at room temperature that has beyond
the maximum amount of solid it can dissolve.
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A SUPERSATURATED SOLUTION
Crystallization Begins.
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A SUPERSATURATED SOLUTION
Crystallization Continues.
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A SUPERSATURATED SOLUTION
A SuperSautrated solution is now saturated. This
is also very exothermic!
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Solubility of a Gas vs Liquid

• In general,
• the higher the temperature of a solution, more
  solid can be dissolved.
• the higher the temperature of a solution, less
  gas can dissolve. Thermal Pollution!

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Solubility of Gas vs Liquiud
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Henrys Law

• As the pressure above a liquid increases, the
  solubility of a gas within a liquid will increase

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Reading a Solubility Curve

• Find the data point on the graph of the
  temperature and solubility of solute in solvent.
• If it is below the line, it is UNSATURATED
• IF it is on the line, it is SATURATED
• If it is above the line, the difference between
  the point and the line is the extra amount that
  is sitting at the bottom.

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Reading a Solubility Curve

• Examples
• What kind of solution occurs when 40g of KCl is
  dissolved in 100 g H2O at 60ºC?
• What kind of solution occurs when 40g of KCl is
  dissolved in 100 g H2O at 40ºC?
• What is the maximum amount of NaBr that can be
  dissolved in 100 g H2O at 60ºC?

unsaturated
saturated
120 g
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Reading a Solubility Curve

• Examples
• 4. What is the maximum amount of KNO3 that can be
  dissolved at 70ºC?
• 5. According to the diamond mark, How much of the
  KNO3 has been added to the water at 70ºC?
• 6. How much extra KNO3 is sitting at the bottom
  of the container at this temperature of 70ºC?

140g
160g
20g
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Factors that Affect the Rate of Hydration

• 1. Temperature
• 2. Particle Size
• 3. Agitation (stirring)

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Section 6.2Concentration
How do we indicate how much of the electrolytes
are in the drink?
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Concentration

• A measure of the amount of solute in a given
  amount of solution
• Qualitative Description
• Dilute small amount of solute compared to
  solvent
• Concentrated large amount of solute compared to
  solvent

Concentrated
Dilute
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Concentrated versus Dilute
solvent
solute
Lower concentration Not as many solute (whats
being dissolved) particles
Higher concentration More solute (whats being
dissolved) particles
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Molarity a quantitiative description of
concentration

• Molarity (M) is a concentration unit that uses
  moles of the solute instead of the mass of the
  solute
• 2M solution is 2 moles of solute dissolved in 1.0
  L of solution

moles
X
Molarity
Liters
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Molarity Example
Example If you dissolve 5.0 moles of NaCl in
300.0 mL of water, what is the molarity?
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Molarity Example
Example If you dissolve 5.0 moles of NaCl in
300.0 mL of water, what is the molarity?
Remember to change mL to L! 300. mL of water
0.300 L
17 M NaCl
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Molarity Example
Example If you dissolve 12 g of NaCl in 150 mL
of water, what is the molarity?
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Molarity Example
Example If you dissolve 12 g of NaCl in 150 mL
of water, what is the molarity?
1 mole NaCl molecules 58.44 g
12 g NaCl
mole NaCl
1
_______ mole NaCl
0.21
g NaCl
58.44
Remember to change mL to L! 150 mL of water
0.150 L
1.4 M NaCl
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Molarity Example
Example How many grams of CaCl2 would be needed
to make 25.0 ml of a 2.5M solution?
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Molarity Example
Example How many grams of CaCl2 would be needed
to make 25.0 ml of a 2.5M solution?
1 mole CaCl2 110.98 g
.063 mol CaCl2
g CaCl2
110.98
6.9 grams CaCl2
CaCl2
1 mol
Remember to change mL to L! 25 mL of water
0.025 L
.0625 moles NaCl
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How to Make a Solution Make 100.0 ml of a
2.0M solution of NaOH

• 1st Convert your moles of solute to grams.
• 2nd Add solute amount to a volumetric flask.
• 3rd Add enough solvent to make the required
  amount of solution and stir.
•  

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How to Dilute a Solution

• M1V1 M2V2
• M1V1 original concentration volume
• M2V2 new concentration and volume

• Example
• What is the molarity of a new solution if you
  diluted 100.0 ml of 3M HCl to 250.0 ml?

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Example What is the molarity of a new solution
if you diluted 100.0 ml of 3M HCl to 250.0 ml?

• M1V1 M2V2
• (3M)(100.0ml) (X)(250.0 ml)
• 300.0 Mml 250.0ml x
• 250.0 ml 250.0ml
• X 1.2 M

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Section 6.3Acidity, pH
How does concentration of acid affect the pH of a
sports drink?
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Review of Acids Arrhenius Definition

• Acids produce Hydronium ion (H3O1) in water
• Hydronium ion is water a hydrogen cation

By this definition, if an acid is to give a H1
to water, then all acids will have hydrogen as
the cation (first element written).
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How do Acids produce Hydronium?
water
acid
Hydrogen cation with some anion
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How do Acids produce Hydronium?
1
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Bases Arrhenius Definition

• Bases produce the hydroxide ion in water

Hydroxide Ion
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According to Bronsted-Lowry

• Is a proton acceptor
• Example NH3 H2O ? OH- NH4
• base acid
  conjugate conjugate
• 
  base acid

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Conjugate Acid-Base Pairs

• Conjugate Acid- substance formed when a base
  gains a H ion.
• Conjugate Base- substance formed when an acid
  loses a H ion.
• Practice Problems Label the acid base on the
  left side of the reaction and the conjugate acid
  conjugate base on the right side.
• a) HCl H2O ? H3O Cl-
• ______ ______ ______
  ______
• b) NH3 H2O ? NH4 OH-
• _____ ______ ______
  ______

acid
base
C.A.
C.B.
base
acid
C.A.
C.B.
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Characteristics of Acids Bases
Acids
Bases
Produce H3O1 (hydronium ion) in water
Produce OH-1 (hydroxide ion) in water
Tastes sour
Tastes Bitter
Feels slippery
React with active metals to form hydrogen gas
Turns red litmus blue
Turns blue litmus red
React with acids to form salt and water
(neutralization reaction)
React with bases to form salt and water
(neutralization reaction)
Both are considered electrolytes
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Strength versus Concentration
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Strong versus Weak Acids
How many hydronium ion anion pairs can you find?
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How many intact acid molecules can you find?
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In a Strong acid Most of the acid molecules have
donated the H1 to water
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Strong versus Weak Acids
How many hydronium ion anion pairs can you find?
1
How many intact acid molecules can you find?
3
In a Weak acid Only a few of the acid molecules
have donated the H1 to water
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Acids and Bases as Electrolytes
Acids and bases dissociate into ions in water
Free-floating ions in water conduct electricity
Acids Bases are electrolytes
Strong acids and bases are strong
electrolytes Weak acids and bases are weak
electrolytes
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pH
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pH Scale

• Is a measure the acidity of a sample

Acids have a pH that are less than 7. Bases have
pH values that are more than 7 Neutral is
considered a pH of 7.
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Calculating pH
pH scale Logarithmic scale of the acidity of a
solution
The pH scale uses base 10
The formula for calculating pH The formula for
calculating hydronium ion concentration
concentration in Molarity
pH has not units
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The - in the pH equation
Because pH is the negative log of concentration
of hydronium, as concentration increases, the pH
goes down.
The lowest pH is the highest concentration of
hydronium ion
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What does a log scale really mean?
Every change of 1 in pH shows a change of 10x in
concentration of hydronium
pH 4 3 2 1
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Example 1

• The pH of a solution changes from a pH of 5 to a
  pH of 3. Did it increase or decrease in hydrogen
  ion concentration? By what factor did it change?

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Example 2 Calculating pH
Example Find the pH if the concentration of
H3O1 is 1.0x 10-8 M
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An example of calculating pH
Example Find the pH if the concentration of
H3O1 is 1.0 x 10-8 M
pH 8.00
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Example 3 Calculating hydronium concentration
Example Find the H3O1 if the pH is 5.0
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An example of calculating hydronium
Example Find the H3O1 if the pH is 5.0
H3O1 1 x 10-5 M
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Auto-ionization of Water

• Water will split into ions. This is
  auto-ionization
• 2 H2O ? H3O1 OH-1
• Water will do this to make sure that at 25C the
  following is true
• H3O1 OH-1 1.0 10-14 M2

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Hydrogen Ion Concentration Values

• If the hydrogen ion concentration is greater than
  hydroxide ion, the solution is ACIDIC with a pH lt
  7
• H gt 1.0 x 10-7 M
• If the hydrogen ion concentration is less than
  hydroxide ion, the solution is BASIC with a pH gt
  7
• H lt 1.0 x 10-7 M
• If the hydrogen ion concentration is equal to
  hydroxide ion, the solution is NEUTRAL with a pH
  7
• H OH- 1.0 x 10-7 M

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Calculating pOH
The formula for calculating pOH The formula
for calculating hydroxide ion concentration To
relate pH and pOH
concentration in Molarity
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Lets Practice 1
Example Find the pOH if the concentration of
OH-1 is 1.0 10-5 M
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Lets Practice 1
Example Find the pOH if the concentration of
OH-1 is 1.0 10-5 M
pOH 5.00
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Lets Practice 2
Example Find the pOH if the pH is 4.
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Lets Practice 2
Example Find the pOH if the pH is 4.
pOH 10
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Lets Practice 3
Example Find the OH-1 if the H is 1.0
x10-9M
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Lets Practice 3
Example Find the OH-1 if the H is 1.0 x10-9
OH- 1.0 x10-5 M
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Lets Practice 4
Example What is the pH if the concentration of
OH- 1.0 x 10-7M
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Lets Practice 4
Example What is the pH if the concentration of
OH- 1.0 x 10-7
pOH 7
pH 7