Concentration(s) of solutions, dilutions, reactionequations. BNS 2019 .pdf · week Topic 19...
Transcript of 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