Solution Stoichiometry

Introduction, Concentration of a solution

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What will I learn? What is solution stoichiometry? Define the following terms: solution; solute;

solvent; and concentration Calculate concentration based on the amount

of solute and the total volume Convert concentration from mass per unit

volume to number of moles per unit volume

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Introduction Many reactions can only occur when reactants

are dissolved to form solutions Stoichiometry is the study of

the quantitative composition of chemical substances

the quantitative changes that take place during chemical reactions

1

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Introduction Many reactions can only occur when reactants

are dissolved to form solutions Solution Stoichiometry is the study of

the quantitative composition of solutions the quantitative changes that take place during

chemical reactions that involve solutions

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Clarification of Terms Solution is a homogeneous liquid mixture Solute + Solvent Solution

Smaller quantity

Larger quantity(normally a liquid)

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Clarification of Terms Solution is a homogeneous liquid mixture Solute + Solvent Solution Concentration is a measure of the amount of

solute dissolved in a given volume

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Molar Concentration

Definition:The amount of solute (in moles) per unit volume of solution (in dm3)

Hence, 1 mole of solute dissolved in 1 dm3 solution has molar concentration of 1 moldm-3

Units: moldm-3

Formula:

solution of volume

solute of amount solution a of ionconcentrat

2

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Molar Concentration

Definition:The amount of solute (in moles) per unit volume of solution (in dm3)

Hence, 1 mole of solute dissolved in 1 dm3 solution has molar concentration of 1 moldm-3

Units: moldm-3

Formula:

V

n c

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Example 1

0.040 moles of BaCl2 is dissolved in water to give a final volume of 250.0 cm3.

a) Calculate the concentration (in moldm-3) of the BaCl2 solution formed

333

16.0100.250

040.02

2

moldm

dm

mol

V

nc BaCl

BaCl

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Example 1

0.040 moles of BaCl2 is dissolved in water to give a final volume of 250.0 cm3.

a) Calculate the concentration (in moldm-3) of the BaCl2 solution formed

333

16.0100.250

040.02

2

moldm

dm

mol

V

nc BaCl

BaCl

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Example 1

0.040 moles of BaCl2 is dissolved in water to give a final volume of 250.0 cm3.

a) Calculate the concentration (in moldm-3) of the BaCl2 solution formed

333

16.0100.250

040.02

2

moldm

dm

mol

V

nc BaCl

BaCl

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Example 1

0.040 moles of BaCl2 is dissolved in water to give a final volume of 250.0 cm3.

b) Calculate the amount of BaCl2 in 10.0 cm3 of the above solution

V

nc BaCl

BaCl2

2

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Example 1

0.040 moles of BaCl2 is dissolved in water to give a final volume of 250.0 cm3.

b) Calculate the amount of BaCl2 in 10.0 cm3 of the above solution

333 100.1016.022

dmmoldmVcn BaClBaCl

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Example 1

0.040 moles of BaCl2 is dissolved in water to give a final volume of 250.0 cm3.

b) Calculate the amount of BaCl2 in 10.0 cm3 of the above solution

333 100.1016.022

dmmoldmVcn BaClBaCl

mol3106.1

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Example 1

0.040 moles of BaCl2 is dissolved in water to give a final volume of 250.0 cm3.

c) Calculate the concentration of Cl- ions in the above solution

)()(2

)(2 2 aqaqaq ClBaBaCl Since

33 32.016.0222

moldmmoldmcc BaClCl

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Example 1

0.040 moles of BaCl2 is dissolved in water to give a final volume of 250.0 cm3.

c) Calculate the concentration of Cl- ions in the above solution

)()(2

)(2 2 aqaqaq ClBaBaCl Since

33 32.016.0222

moldmmoldmcc BaClCl

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Example 1

0.040 moles of BaCl2 is dissolved in water to give a final volume of 250.0 cm3.

c) Calculate the concentration of Cl- ions in the above solution

)()(2

)(2 2 aqaqaq ClBaBaCl Since

33 32.016.0222

moldmmoldmcc BaClCl

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Example 2

1.06 g of anhydrous sodium carbonate, Na2CO3 was dissolved in 250 cm3 of solution. What is the concentration of the solution in moldm-3?

molgmol

g

M

mn CONa 0100.0

)0.16(312)1.23(2

06.1132

333

0400.010250

0100.032

32

moldm

dm

mol

V

nc CONa

CONa

??

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Example 2

1.06 g of anhydrous sodium carbonate, Na2CO3 was dissolved in 250 cm3 of solution. What is the concentration of the solution in moldm-3?

molgmol

g

M

mn CONa 0100.0

)0.16(312)1.23(2

06.1132

333

0400.010250

0100.032

32

moldm

dm

mol

V

nc CONa

CONa

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Example 2

1.06 g of anhydrous sodium carbonate, Na2CO3 was dissolved in 250 cm3 of solution. What is the concentration of the solution in moldm-3?

molgmol

g

M

mn CONa 0100.0

)0.16(312)1.23(2

06.1132

333

0400.010250

0100.032

32

moldm

dm

mol

V

nc CONa

CONa

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Example 2

1.06 g of anhydrous sodium carbonate, Na2CO3 was dissolved in 250 cm3 of solution. What is the concentration of the solution in moldm-3?

molgmol

g

M

mn CONa 0100.0

)0.16(312)1.23(2

06.1132

333

0400.010250

0100.032

32

moldm

dm

mol

V

nc CONa

CONa

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Example 2

1.06 g of anhydrous sodium carbonate, Na2CO3 was dissolved in 250 cm3 of solution. What is the concentration of the solution in moldm-3?

molgmol

g

M

mn CONa 0100.0

)0.16(312)1.23(2

06.1132

333

0400.010250

0100.032

32

moldm

dm

mol

V

nc CONa

CONa

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

3342

342342

)(

)()(

AlSOAl

SOAlSOAlcc

V

n

V

M

m

3

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

3342

342342

)(

)()(

AlSOAl

SOAlSOAlcc

V

n

V

M

m

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

3342

342342

)(

)()(

AlSOAl

SOAlSOAlcc

V

n

V

M

m

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

3342

342342

)(

)()(

AlSOAl

SOAlSOAlcc

V

n

V

M

m

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

molgmol

g

M

mn SOAl 0371.0

)]0.16(41.32[3)0.27(2

7.121342

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

molgmol

g

M

mn SOAl 0371.0

)]0.16(41.32[3)0.27(2

7.121342

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

molgmol

g

M

mn SOAl 0371.0

)]0.16(41.32[3)0.27(2

7.121342

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

molgmol

g

M

mn SOAl 0371.0

)]0.16(41.32[3)0.27(2

7.121342

33

331071.3

10100

0371.0342

342

moldm

dmV

nc

SOAl

SOAl

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

molgmol

g

M

mn SOAl 0371.0

)]0.16(41.32[3)0.27(2

7.121342

33

331071.3

10100

0371.0342

342

moldm

dmV

nc

SOAl

SOAl

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

molgmol

g

M

mn SOAl 0371.0

)]0.16(41.32[3)0.27(2

7.121342

33

331071.3

10100

0371.0342

342

moldm

dmV

nc

SOAl

SOAl

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

33

331071.3

10100

0371.0342

342

moldm

dmV

nc

SOAl

SOAl

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

33

331071.3

10100

0371.0342

342

moldm

dmV

nc

SOAl

SOAl

)(2

4)(3

)(342 32 aqaqaqSOAlSOAl Since

3333 1042.71017.322

3423

moldmmoldmcc SOAlAl

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

33

331071.3

10100

0371.0342

342

moldm

dmV

nc

SOAl

SOAl

)(2

4)(3

)(342 32 aqaqaqSOAlSOAl Since

3333 1042.71017.322

3423

moldmmoldmcc SOAlAl

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Example 3

What is the concentration in moldm-3 of Al3+ in a solution made by dissolving 12.7 g aluminium sulphate, Al2(SO4)3 in sufficient water to make 100 cm3 of solution?

33

331071.3

10100

0371.0342

342

moldm

dmV

nc

SOAl

SOAl

)(2

4)(3

)(342 32 aqaqaqSOAlSOAl Since

3333 1042.71017.322

3423

moldmmoldmcc SOAlAl

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Other Concentration Units

Sometimes, concentration can be expressed in mass per unit volume

))

33-

(dm solution of volume

(g) solute of mass(gdm ionconcentrat

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Other Concentration Units

Sometimes, concentration can be expressed in mass per unit volume

Units: gdm-3

))

33-

(dm solution of volume

(g) solute of mass(gdm ionconcentrat

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Other Concentration Units

Sometimes, concentration can be expressed in mass per unit volume

Concentration (in gdm-3) can be converted to molar concentration via the equation:

)

))

1-

-33-

(gmol mass molar

(gdm ionconcentrat(moldm ionconcentrat

))

33-

(dm solution of volume

(g) solute of mass(gdm ionconcentrat

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Example 1

2.00 g of NaOH is dissolved in water to give a final volume of 150.0 cm3.

a) Calculate the concentration (in gdm-3) of the NaOH solution formed

))

33-

(dm solution of volume

(g) solute of mass(gdm ionconcentrat

33100.150 dm

2.00g

33.13 gdm

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Example 1

2.00 g of NaOH is dissolved in water to give a final volume of 150.0 cm3.

b) Calculate the concentration (in moldm-3) of the solution above

)

))

1-

-33-

(gmol mass molar

(gdm ionconcentrat(moldm ionconcentrat

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Example 1

2.00 g of NaOH is dissolved in water to give a final volume of 150.0 cm3.

b) Calculate the concentration (in moldm-3) of the solution above

)

))

1-

-33-

(gmol mass molar

(gdm ionconcentrat(moldm ionconcentrat

3

11333.0

401160.23

moldmgmolgmol

-3-3 13.3gdm13.3gdm

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Example 1

2.00 g of NaOH is dissolved in water to give a final volume of 150.0 cm3.

b) Calculate the concentration (in moldm-3) of the solution above

)

))

1-

-33-

(gmol mass molar

(gdm ionconcentrat(moldm ionconcentrat

3

11333.0

401160.23

moldmgmolgmol

-3-3 13.3gdm13.3gdm

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Example 1

2.00 g of NaOH is dissolved in water to give a final volume of 150.0 cm3.

b) Calculate the concentration (in moldm-3) of the solution above

)

))

1-

-33-

(gmol mass molar

(gdm ionconcentrat(moldm ionconcentrat

3

11333.0

401160.23

moldmgmolgmol

-3-3 13.3gdm13.3gdm

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What have I learnt? What is solution stoichiometry? Define the following terms: solution; solute;

solvent; and concentration Calculate concentration based on the amount

of solute and the total volume Convert concentration from mass per unit

volume to number of moles per unit volume

End of Lecture 1