Concentration of solutions

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Transcript Concentration of solutions

Slide 1

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 2

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 3

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 4

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 5

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 6

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 7

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 8

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 9

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 10

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 11

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 12

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 13

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 14

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 15

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 16

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 17

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 18

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4


Slide 19

CONCENTRATION OF
SOLUTIONS
Day 4

CONCENTRATION
A measurement of the amount of solute in a

given amount of solvent or solution (unit of
measurement = molarity)
Kind of like the “strength” of the solution

MOLARITY
Molarity (M)=

mol solute
L solution

MOLARITY
Example #1: If we put 0.500 mol of
sodium hydroxide into 1.00 L of solution,
what is the molarity of the solution?

Molarity= mol solute/L sol’n

M=

=

0.500 mol NaOH

1.00 L

0.500 M NaOH

Example #2: What is the

molarity if we have 80.0 g
NaOH in 1.00 L of solution?

Molarity= mol solute/L sol’n
80.0 g NaOH

1 mol NaOH =2.00 mol
40.0 g NaOH

2.00
M
NaOH
=
2.00
mol
NaOH
M=

1.00 L

MOLARITY
Example #3: How many moles of KOH

are in 0.500 L of 0.100 M KOH?

Molarity= mol solute cross multiply!
1
L sol’n

mol KOH= (0.100 M KOH) (0.500 L)

= 0.0500 mol KOH

MOLARITY
Ex 4: How many grams of KOH

are in 2.75 L of 0.25 M KOH?

Molarity = moles
cross multiply!
L
Moles = Molarity * L
= 0.25 mol/L * 2.75L
= 0.69 moles KOH
0.69 mol KOH

56.097 g KOH = 38.7 g KOH
1 mole KOH
(39)

MOLARITY - DILUTION
Some chemicals are sold as pre-prepared
concentrated solutions (stock solutions).

To be used, stock solutions usually must be
diluted.

ALWAYS ADD ACID

2.) MOLARITY - DILUTION

MSVS = MDVD
• MS – Molarity of stock solution
• VS – Volume of stock solution (L or mL)
• MD – Molarity of dilute solution
• VD – Volume of dilute solution (L or mL)

*In dilution calculations,
the units for volume
must be the same.

2.) MOLARITY - DILUTION
Example #1: How much 12.0 M HCl is

required to make 2.50 L of a 0.500 M
solution?
Ms * Vs = MD * VD

MS VS = MD VD
MS = 12.0 M HCl
VS = ??

VS =

OR M1 V1 = M2 V2

MD = 0.500 M HCl
VD = 2.50 L

(0.500 M HCl) (2.50 L)
(12.0 M HCl)

= 0.104 L HCl

2.) MOLARITY - DILUTION
Example #2: What volume of a 1.50 M

solution can be made using 0.0250 L of
18.0 M H2SO4 ?
MS VS = MD VD

MS VS = MD VD
MS = 18.0 M H2SO4
VS = .0250 L

VD =

MD = 1.50 M H2SO4
VD = ????

(18.0 M H2SO4) (.0250 L)
(1.50 M H2SO4)

= 0.300 L H2SO4