concentration(s) of solutions, dilutions, reactionequations. bns 2019 .pdf · week topic 19...

week Topic

19 Sept 2019

SI units, density, amount, formulas

Concentration(s) of solutions, dilutions, reaction equations.

Oxidation numbers, reaction equations.

Stoichiometry, calculations.

Equilibriums, Acid-base theories, pH calculations. Base of organic chemistry (Formulas, reactions)

26 Sept 2019

03 Oct 2019

10 Oct 2019

17 Oct 2019

24 Oct 2019

31 Oct 2019

7 Nov 2019 Exam (first; later other opportunities)

Topics of the lectures

Basic mathematical operations

c·(a+b) = c·a + c·b c·(a·b) = c·a·b

ab · c = a·c

bab :c = =a:c

ba

b ·c

ab

1 ba=

ab

a ba= a · = b

= g · = molgmol

g molg

With units:

then:

a = b·c

and

a cb =

a b

= cIf

a

b c

avarege =a1 + a2 + a3 + … + an

n

rounding: 1.52 / 52.24 = 0.029096477

0.02 - wrong

0.0291 - correct

Basic mathematical operations

2x + 143

= 3x

A simple equation

2x + 14 = 3 · 3x

2x + 14 = 9x

14 = 7x

·3

- 2x

:7

2 = x

SI base unitsQuantity Name Symbollength metre (meter) mmass kilogram kgTime second s

amount of substance mole molTemperature kelvin K

luminous intensity candela cdelectric current ampere A

SI units

SI prefixes

Signification Multiplier

Name Symbol Signification

x1000000000000 1012 tera T

x1000000000 109 giga G

x1000000 106 mega M

x1000 103 kilo k

x10 101 deca da

10-1 deci d /10

10-2 centi c /100

10-3 milli m /1000

10-6 micro /100000

10-9 nano n /1000000000

1 kg = 1 000 g = 1 000 000 mg

1 g = 1 000 mg

1 m3 = 1 000 dm3 = 1 000 000 cm3

1 dm3 = 1 000 cm3

1 cm3 = 1 ml

1 l = 1 000 ml = 1 dm3

Multiplier Name Symbol1000 kilo k10 deci d

0.01 centi c0.001 milli m

0.00001 micro

0 °C = 273 K X °C = (X + 273) KT = t + 273

1 mol = 1 000 mmol

SI prefixes

SI units

45 g = kg

25 g = mg

3.1 dm3 = cm3

150 cm3 = l

538 dm3 = m3

12 ml = cm3

20 °C = K 298 K = °C

0.71 mol = mmol

Multiplier Name Symbol1000 kilo k10 deci d

0.01 centi c0.001 milli m

0.00001 micro

2.4 m3 = l

52 mmol = mol

Change the units!

Change the units! - answers

45 g = kg

25 g = mg

3.1 dm3 = cm3

150 cm3 = l

538 dm3 = m3

12 ml = cm3

20 °C = K 298 K = °C

0.71 mol = mmol

Multiplier Name Symbol1000 kilo k10 deci d

0.01 centi c0.001 milli m

0.00001 micro

2.4 m3 = l

52 mmol = mol

0.045

25000

3100

0.15

0.538

12

2400

293 25

710 0.052

„Small differences…”

CuO Cu2O= COCO2

0,1-1%>10%

=

Lifetime < 1sec

H+ H

H2

P=P E=

P EE P=H- PE E=

I’m sad…

Atomic number (Z): number of protons in the atom(determine the quality of the atom)

Mass number (A): number of protons + number of neutrons(determine the mass of the atom)

Characteristic atomic symbols

Mass number

Building blocks

1

2 3 4 5 6 7

Number of Valence electrons 8

Electronegativity

Elementary metals: we write just the atomic symbol

e.g. Cu, Ag, Na, Al, Pb, etc.

(never Cu2, Na3)

Building blocks – elementary metals

Building blocks – Cations (~ metal ions)

Members of this group of metalsdisplay a number of valencies

Alkali metals: +1 (e.g. Li+, Na+, K+)

Alkali earth metals: +2 (e.g. Mg2+, Ca2+, Sr2+,Ba2+)Al: +3

Other metals: we have to inform youe.g. iron(III)- means Fe3+

lead(II)- means Pb2+

Metals form positive ions (cations) – never negative ions (anions)

But some metal ion from the d-block has only one charge:

Members of this group of metalsdisplay a number of valencies

Building blocks – Cations (~ metal ions)

Ag+, Zn2+, Ni2+, Co2+

A special one:Hg2+ Hg2+ (not Hg+ !!)

2

Two non-metal cation: hidrogen ion: H+

ammonium ion: NH+4

Halide ions

fluoride F-

chloride Cl-bromide Br-

iodide I-

Building blocks – Anions (nonmetal ions)

sulfide S2-

oxide O2-

peroxide O2-2

hidride H-

2

A polyatomic ion, also known as a molecular ion, is a charged chemical species (ion) composed of two or more atoms covalently bonded or of a metal complex that can be considered to be acting as a single unit.

Building blocks – (Poliatomic) Anions

sulfuric acid H2SO4sulfate ion SO42-

Polyatomic ions „Mother” compound”

sulfurous acid H2SO3*sulfite ion SO32-

dihydrogen sulfide H2Ssulfide ion S2-

hydrogen sulfide ion HS-

thiosulfate ion S2O32- thiosulfuric acid H2S2O3*

* not exist; in real it is SO2·H2O

* not exist

Building blocks – (Poliatomic) Anions

Polyatomic ions „Mother” compound”

nitric acid HNO3nitrate ion NO3-

nitrous acid HNO2nitrite ion NO2-

carbonic acid H2CO3

carbonate ion CO32-

hydrogen carbonate ion HCO3-

water H2Ohydroxide ion OH-

oxide ion O2-

phosphoric acid H3PO4phosphate ion PO43-

23

Polyatomic ions

NH3 = ammonia=

chromate ion CrO42-

dichromate ion Cr2O72

permanganate ion MnO4-

ammonium ion NH4+

What is the formula of calcium chloride?

Ca2+ Cl-

Ionic bond

Cl-

Ca2+

Calcium chloride

Ca2+ Cl-

CaCl

Ionic bond

Ca2ClCa2+

Cl-

Ca2+

Ionic bond

Calcium chloride

Ca2+ Cl-

CaCl2 Cl-Ca2+Cl-

Ionic bond

Calcium chloride

Ca2+ Cl-

Cl-

Ca2+

Cl-Cl-CaCl3

Ionic bond

Calcium chloride

Ca2+ Cl-

Ionic bond

What is the formula of magnesium-nitrate?

Mg2+

what is the formula of magnesium-ion?

Ionic bond

What is the formula of magnesium nitrate?what is the formula of nitrate-ion?

Polyatomic ionnitric acid HNO3nitrate ion NO3

-

„Mother” compound”

NO3-

Mg2+

Magnesium nitrate

Mg2+ NO3-

Mg2+Mg2+

MgNO3

Mg(NO3)2

Mg(NO3)3 NO3-

NO3-

NO3-NO3

-NO3-

Ionic bond

What is the formula of magnesium-bromide?

what is the formula of magnesium-ion?

what is the formula of bromide-ion?

Mg2+

Br-

What is the formula of sodium sulfate?

Na+

Ionic bond

Ionic bond

what is the formula of sulfate-ion?

Polyatomic ion „Mother” compound”

sodium sulfate

Na1+ SO42-

Na2SO4

What is the formula of sodium sulfate?

sulfuric acid H2SO4sulfate ion SO42-

Na+Na+ SO42-

Na+

SO42-Na+

Na+

Na(SO4)2

Na3SO4

Na+

SO42- SO4

2-

Na2(SO4)1

Ionic bond

What is the formula of copper(I)-oxide?

Cu1+

what is the formula of copper(I)-ion? what is the formula of oxid-ion?

O2-

Cu O2 1

Correct formula: Cu2O

35

Write the formula of…

Sodium-oxide

Copper(II)-oxide

Silver-sulfide

Ammonium-sulfate

Magnesium-nitrate

Potassium-phosphate

Aluminium-sulfide

Calcium-hidroxide

Na+ + O2- Na2O

Cu2+ + O2- CuO

Ag+ + S2- Ag2S

NH4+ + SO4

2- (NH4)2SO4

Mg2+ + NO3- Mg(NO3)2

K+ + PO43- K3PO4

Al3+ + S2- Al2S3

Ca2+ + OH- Ca(OH)2

1

2 3 4 5 6 7

Number of Valence electrons 8

Covalent bonds (nonmetal atoms)

How to predict number of bonds each element makes?

F 1 bond e.g. HF, HCl, CCl4,

often the same: Cl, Br, I BUT: HClO4

O 2 bond

e.g. H2O, O2, CH3OH

e.g. H2S

often the same: S BUT: SO2, SO3

N 3 bond

often the same: P

e.g. NH3, R3N

BUT: H3PO4

Covalent bonds (nonmetal atoms)

How to predict number of bonds each element makes?

4 bondCthe same: Si

e.g. CO2, CCl4, any organic compondSiF4

Covalent bonds (nonmetal atoms)

Density

wolframaluminummagnesium

Density () =total mass of the object

total volume of the object = m

V

unit: g

cm3 ;g

dm3 ;kgm3

1.74 kg 2.70 kg 19.25 k g

Change the formula!

= mV

m = ?

m

V

gdm31224 = = = 1.224

1224 g1 dm3

1224 g1000 cm3

gcm3

gcm3

gdm31224 =

Change the units!

V = ?

Calculate!

The mass of a brick is 4 kg.The volume of the same brick is 2.3 dm3.Calculate the density of thisbrick in g/cm3 !

m

Vm = 4 kg = 4000 g

V = 2.3 dm3 = 2300 cm3

= m / V = 4000 g / 2300 cm3 = 1.74 g/cm3.

1.

2. The density of a solution is 1.12 g/cm3. We have 4 dm3 of this solution.Calculate the mass of this solution!

= 1.12 g/cm3

V = 4 dm3 = 4000 cm3

= mV

m = · V = 1.12 g/cm3 · 4000 cm3 =

m = 4480 g = 4.48 kg

mass

m

amount

number of…

n

Avogadro’s number

dozen= 12

mol = 600 000 000 000 000 000 000 000 = 6·1023

In chemistry, the quantity or amount of matter (= number of particles, N)

is expressed in moles. The mole number, n = N/NA, where NA is the

Avogadro’s number, is 6.0221023 mol1.

Avogadro’s number

1 mol substance always contains 6.0221023 particles.

Molecular mass (M) unit: g/mol= mass of 1 mol (6·1023 pieces) particles

m = M · n

m

M n

M(S) = 32 g/mol n = 2 mol S m = 2·32 = 64 g

M(S) = 32 g/mol n = 5 mol S m = 5·32 = 160 g

Unit price: 3 €/roll 2 rolls total price: 2·3=6 €

M(S) = 32 g/mol 2 mol total mass:

m = 2·32=64 gMolecular mass(=mass of the unit)

Molecular mass (M) unit: g/mol

Mass of 1 mol (6·1023 pieces) particles1 mol S 32 g M(S) = 32 g / mol1 mol copper 63.54 g M(Cu) = 63.54 g / mol1 mol NaCl 58.5 g M(NaCl) = 58.5 g / mol

because M(H2O) = 2·M(H)+M(O) = 2·1+16 = 18 g/mol

because M(NaCl) = M(Na)+M(Cl) = 23 + 35.5 = 58:5 g/mol

1 mol water 18 g M(H2O) = 18 g / mol

M(NaOH) =

Calculate the molecule mass of the next compounds!

M(H2CO3) =

M(HNO3) =

M(Na2S2O3) =

Calculate the molecule mass of the next compounds! - answers

40 g/mol

62 g/mol

63 g/mol

158 g/mol

M(NaOH) =

M(H2CO3) =

M(HNO3) =

M(Na2S2O3) =

m = n · M

M (Na) = 23 g/mol

m = 23 g/mol · 4.5 mol = 103.5 g

n = 4.5 mol

m = ? g

1. We have 4.5 mol sodium. Calculate the mass of it!

Calculate!

2. A flask contains 42.5 g ammonia (NH3). Calculate the amountof the gas!

m = n · M

M(NH3) = M(N) + 3·M(H) = 14 + 3·1 = 17 g/molm = 42.5 g

n = ? mol

n = = 42.5/17 = 2.5 mol mM

m

M n

3. The density of water is 1000 g/dm3. Calculate the amount of81 cm3 water!

Calculate!

m

M n

M(H2O) = 18 g/mol

= 1000 g/dm3

n = ? mol

V = 81 cm3

nVmM

= mV

m = · V = 1000g/dm3 · 0.081dm3 = 81 g

V = 81 cm3 = 0.081dm3

M · n = m n = m/M = 81g / 18g/mol = 4.5 mol

The end

Tuesday

Write the formula of the next ionic compounds!

sodium-bromide

silver-sulfideiron(II)-oxide

lithium-iodide

zinc-carbonate

copper(II)-nitrate

Write the formula of the next ionic compounds! - Answers

sodium-bromide

silver-sulfideiron(II)-oxide

lithium-iodide

zinc-carbonate

copper(II)-nitrate

NaBr ZnCO3

Ag2S

Cu(NO3)2LiI

FeO

Write the formula of the next compounds!

dihydrogen-sulfide

aluminium-oxide

bromine

mercury(II)-chloride

mercury(I)-bromide

ammonium-nitrate

potassium-sulfate

dihydrogen-sulfide

aluminium-oxide

bromine

mercury(II)-chloride

mercury(I)-bromide

ammonium-nitrate

potassium-sulfate

H2S

Al2O3

Br2

HgCl2

HgBr

Write the formula of the next compounds! -answers

NH4NO3

K2SO4

X = ?

3.1 l = cm3

182 cm3 = dm3

2.4 dm3 = cm3

12 mg = g

34 mmol = mol

1.4 m3 = cm3

1.

Homework

2. Change the units!

3. The volume of a solution is 2.1 dm3. Itsmass is 1742 g. Calculate the density of this solution!

You have a rock (A) with a volume of 15cm3 and a mass of 45 g. You have anotherrock (B) with a volume of 30 cm3 and a density of 1215 kg/m3. Which one is theheavier?

4.

Calculate the density in g/ml of 3000 ml of solution weighing 6 kg.

5.

A flask contains 85 g ammonia (NH3). The volume of this gas is 125 dm3. Calculate the amount and the density of the gas!

6.

Calculate the mass of 0.25 moles of water! 7.

Calculate the molar mass of a puresubstance if 1.75 moles of thesubstance has a mass of 29.792 g

8.

20 - 2x3x

+ 3 = 7

70 - 2x5

= 12a)

b)

Homework

9. Write the formula of the next compounds!

silver-nitrate

potassium-carbonate

silver-iodide

lead(II)-nitrate

aluminium-phosphate

iron(III)-oxide

Homework-answers

9. AgNO3, K2CO3, AlPO4, Fe2O3, Pb(NO3)2, AgI

1. a) x=5 b) x = 1

2. 3.1 l = 3100 cm3

2.4 dm3 = 2400 cm334 mmol = 0.034 mol

182 cm3 = 0.182 dm3

12 mg = 0.012 g1.4 m3 = 1 400 000 cm3

3. 0.83 g/cm3 4. The „A” rock is the heavier.

5. 2 g/ml6. n = 5 mol, = 0.68 g/dm3

7. m = 4.5 g 8. M = 17.024 g/mol