ib unit 2 guided notes - web viewgroup trends should include the treatment of the reactions of...

Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________

Lesson 1:Review of Periodic Table Structure

Thursday, October 2, 2014

IB Understandings The periodic table is arranged into four blocks associated with the four

sublevels – s, p, d and f The periodic table consists of groups (vertical columns) and periods

(horizontal columns) The period number (n) is the outer energy level that is occupied by electrons The number of the principal energy level and the number of the valence

electrons in an atom can be deduced from its position on the periodic table The periodic table shows the positions of metals, non-metals and metalloids

Applications and skills: Deduction of the electron configuration of an atom from the element’s

position on the periodic table, and vice versa.

Guidance: The terms alkali metals, halogens, noble gases, transition metals, lanthanoids

and actinoids should be known. The group numbering scheme from group 1 to group 18, as recommended by

IUPAC, should be used.

Periodic Table Development:Dobreiner’s Triads

Newlands Octaves

Mendeleev

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Elements show gradual changes in certain physical properties as one moves across a period or down a group in the periodic table. These properties repeat after certain intervals. In other words they are ____________________________.

Periodic properties include:

1.

2.

3.

4.

5.

Elements are arranged by increasing __________________________________________________.

Groups

Periods

Group Number Name Characteristics

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Metals

Metalloids

Non-Metals

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Lesson 2: Periodic Trends

Friday, October 3, 2014

IB Understandings Vertical and horizontal trends in the Periodic Table exist for atomic radius,

ionic radius, ionization energy, electron affinity, and electronegativity.Guidance

Only examples of general trends across periods and down groups are required. For ionization energy the discontinuities in the increase across a period should be covered.

o Trends in metallic and non-metallic behaviour are due to the trends above.

o Oxides change from basic through amphoteric to acidic across a period.

Applications and skills: Prediction and explanation of the metallic and non-metallic behaviour of an

element based on its position in the Periodic Table.

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Discussion of the similarities and differences in the properties of elements in the same group, with reference to alkali metals (Group 1) and halogens (Group 17).

Guidance Group trends should include the treatment of the reactions of alkali metals

with water, alkali metals with halogens and halogens with halide ions. Construction of equations to explain the pH changes for reactions of Na2O,

MgO, P4O10, and the oxides of nitrogen and sulfur with water.

Periodicity:

Effective Nuclear Charge

Atomic Radius

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Ionic Radius

Describe and explain the trend in radii of the following atoms and ions: O2–, F–, Ne, Na+, and Mg2+.

Ionization Energy

Electron Affinity

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Electronegativity

Melting Points

Metals vs. Non-Metals:

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Let’s Practice

1 (a) Explain what is meant by the atomic radius of an element.(b) The atomic radii of the elements are found in Table 9 of the IB data booklet.

(i) Explain why no values for ionic radii are given for the noble gases. (ii) Describe and explain the trend in atomic radii across the Period 3 elements.

2 Si4+ has an ionic radius of 4.2 × 10–11 m and Si4– has an ionic radius of 2.71 × 10–10

m. Explain the large difference in size between the Si4+ and Si4– ions.

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Lesson 3: Practice!

Remember when studying that the group of an element on the Periodic Table also tells you the number of valence electrons for that element! Electron Shielding Effect:

Atomic Radius:

We typically measure atomic radius at ____________________________________________ where we look at atoms in chemical bonds with other atoms of the same element and take ½ the diameter between the two nuclei

There is also ________________________________________________________________________ or _____________________________________________________________ radius for things like Noble Gases that do not bond; take a look at these atoms in the solid phase and measure the distance between two nuclei

Which ion would have a larger ionic radius, Na+ or Mg2+?

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Melting Points

Comparing melting points is complex because it depends on bonding as well as nuclear charge

Trends down Groups 1 through 17 can be explained as elements in each group bond in the same way!

Melting points ___________________________________down Group 1 as these metallic bonds have delocalized electrons and as you move down the group the attraction decreases

Melting points _________________________________ down Group 17 because these diatomic elements are held together by London Dispersion forces which get stronger as the electron cloud gets bigger

Melting points generally rise from left to right until Group 14 and then fall from Group 14 to Group 18

Lesson 4: More Trends

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Warm-Up: Why does I2 have a higher melting point than F2?

Why does aluminum have a higher melting point than sodium?

Metals:

Metallic properties are related to ionization energy; the lower the ionization energy, the more metallic an element is

A metallic structure consists of a regular lattice of positive ions in a _______________________________________________________________________________________

Metallic character ___________________________ from left to right and ________________________________ from top to bottom

1.

2.

3.

4.

5.

Mercury:

Non-Metals:

1.

2.

Metalloids:

1.

Alkali Metals

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Physical Properties Chemical Properties

Reactions

Group 1 Reactions with WaterLithium

Sodium

Potassium

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Francium

Cesium

Group 17 – Halogens

Physical Properties Chemical Properties

Reactions

Salts:

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Displacement Reactions with Water

Silver + Halides

Group 18 – Noble Gases

1.

2.

3.1. Why are alkali metals called alkali?

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2. How are halides formed?

3. Why does Cl- displace Br- in a displacement reaction?

4. How do the reactivities of the alkali metals and the halogens vary down a group?

5. Which property of the halogens increases from fluorine to iodine? A. ionic charge B. electronegativity C. melting point of the element D. chemical reactivity with metals

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Lesson 5: Oxides and pH Trends

Warm-Up: Explain why each trend occurs below in terms of effective nuclear charge.

Oxides:

pH of Oxides: Metal oxides are basic; they react with water to form metal hydroxides

CaO(s) + H2O(l) à Ca(OH)2(aq) Non-metallic oxides are acidic: they react with water to form acidic solutions

CO2(g) + H2O(l) à H2CO3(aq) Carbonic Acid If an oxide can act both as an acid and a base, it is classified as

amphoteric!Al2O3(s) + 2NaOH(aq) + 3H2O(l) à 2NaAl(OH)4 (acts as an acid)

Al2O3(s) + 6HCl(aq) à 2AlCl3(aq) + 3H2O(l) (acts as a base)

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Metal Oxides

Metalloid Oxides

Non-Metal Oxides

As you go across period 3, the ionic character _________________________________. As you go down a group of oxides, the ionic character _________________________.

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Basic Character Sodium and magnesium oxides will dissolve in water to form alkaline

solutions:o Na2O (s) + H2O (l) à 2NaOH (aq)o MgO (s) + H2O (l) à Mg(OH)2 (aq)

Basic oxides react with an acid to form a salt and water:o MgO (s) + HCl (aq) à MgCl2 (aq) + H2O (l)o Li2O (s) + HCl (aq) à LiCl (aq) + H2O(l)

Acidic Character Non-metallic oxides react with water to produce acidic solutions:

o P4O10(s) + 6H2O à 4H3PO4(aq)o P4O6(s) + 6H2O à 4H3PO3 (aq)

Sulfur trioxide reacts with water to produce sulfuric acid:o SO3 (l) + H2O (l) à H2SO4 (aq)

Sulfur dioxide reacts with water to produce sulfic acid Dichlorine heptoxide reacts with water to produce chloric acid Dichlorine monoxide reacts with water to produce chlorous acid Silicon dioxide does not react with water, but will react with alkalis to form

silicates.

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Lesson 7: Introduction to Transition Metals (HL material)

IB Understandings Transition elements have variable oxidation numbers, form complex ions

with ligands, have coloured compounds, and display catalytic and magnetic properties.

Guidance Common oxidation numbers of the transition metal ions are listed in the IB

Data booklet in sections 9 and 14. Zn is not considered to be a transition element as it does not form ions with

incomplete d orbitals. Transition elements show an oxidation number of +2 when the s electrons

are removed.

IB Applications and Skills Explanation of the ability of transition metals to form variable oxidation

states from successive ionization energies. Explanation of the nature of the coordinate bond within a complex ion. Deduction of the total charge given the formula of the ion and ligands

present. Explanation of the magnetic properties in transition metals in terms of

unpaired electrons.

d-Block metals:

D-block cont…

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REVIEW: Electron Configuration Exceptions! Why?

Effective Nuclear Charge in D-block

Why is this?

Why is this amazing?

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Physical Propterties

1.

2.

3.

4.

5.

Chemical Properties

1.

2.

3.

Why is zinc not considered a transition metal?

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Scandium

Oxidation States:

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Important Points For IB! All the transition metals show both the +2 and +3 oxidation states. The M3+

ion is the stable state for the elements from scandium to chromium, but the M2+ state is more common for the later elements. The increased nuclear charge of the later elements makes it more difficult to remove a third electron.

The maximum oxidation state of the elements increases in steps of +1 and reaches a maximum at manganese. These states correspond to the use of both the 4s and 3d electrons in bonding. Thereafter, the maximum oxidation state decreases in steps of –1.

Oxidation states above +3 generally show covalent character. Ions of higher charge have such a large charge density that they polarize negative ions and increase the covalent character of the compound (see Figure 3.13).

Compounds with higher oxidation states tend to be oxidizing agents. The use of potassium dichromate(VI) (K2Cr2O7), for example, in the oxidation of alcohols.

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Lesson 8: Complex Ions and Coordinate Complexes

Complex Ions: Transition metal ions in solution have a high charge density These ions attract polar water molecules which form

________________________________________________________________________________________ REMBEMBER: A coordinate bond is a

__________________________________________________________________________________________________________________________________________________________________________________

Ligands

When a complex is formed where a central ion is surrounded by molecules or ions which possess a lone pair of electrons that can enter into a coordinate bond, the surrounding species are called _____________________________________

Ligands have to have a _________________________________________________ to donate! The number of coordinate bonds from the ligands to the central atom is

called the ____________________________________________________________________________

Shapes of Complex Ions

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Coordination Number Oxidation Number of

Central IonShape

Let’s Practice: Try to figure out the oxidation number of the following ions:

Oxidation Number of Central Ions1.

2.

3.

Hints!

1.

2.

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What is the charge for the complex ion in compound? [Cr(H2O)6]Cl3?

What is the charge for the complex ion in the following compounds? [CrCl(H2O)5]Cl2.H2O and [CrCl2(H2O)4]Cl.2H2O

Platinum (II) can form a complex ion with 1 ammonia and 3 chloride ligands. What is the overall charge and formula for this complex ion?

LigandsMonodentate

Polydentate

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EDTA Usage:1.

2.

3.

4.

5.

6.

Chelating Agents

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Let’s Practice

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Lesson 9 – d-Block Elements as Catalysts and Magnets

A _____________________________ alters the rate of reaction by providing an alternate pathway with a lower activation energy

Catalysts are extremely important as they allow reactions to proceed __________________________________

In a__________________________________ catalyst, the catalyst is in the same state as the reactants

In a __________________________________ catalyst, the catalyst is in a different state as the reactants

Transition metals are super effective __________________________________ ____________________since they can use their s and d electrons to weakly interact with reactant molecules and arrange them in the correct orientation (remember that in order for a reaction to occur, the reactants must combine with enough energy in the correct orientation!)

Heterogeneous Catalyst:Iron

Nickel

Pt and PD

MnO2

V2O5

Nickel (with oils)

Hydrogenation of Oils:

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Homogeneous Catalysts:Iron

Cobalt

Catalytic Converters:

Magnetism

Diamagnetism

Paramagnetism

Ferromagnetism

Iron, nickel, and cobalt are ______________________________________________; the unpaired d electrons in large numbers of atoms line up with parallel spins in regions called domains.

Paramagnetism increases with the number of unpaired electrons so generally _____________________________________________________________________across the Periodic Table, reaches a maximum at chromium, and decreases. Zinc has no unpaired electrons and so is diamagnetic.

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________ Lesson 10 – D-Sublevel Splits and Colored Ions

Understandings: The d sub-level splits into two sets of orbitals of different energy in a

complex ion. Complexes of d-block elements are coloured, as light is absorbed when an

electron is excited between the d orbitals. The colour absorbed is complementary to the colour observed.

Guidance The relation between the colour observed and absorbed is illustrated by the

colour wheel in the IB Data booklet in section 17. Applications and Skills

Explanation of the effect of the identity of the metal ion, the oxidation number of the metal, and the identity of the ligand on the colour of transition metal ion complexes.

Guidance Students are not expected to recall the colour of specific complex ions. Explanation of the effect of different ligands on the splitting of the d orbitals

in transition metal complexes and colour observed using the spectrochemical series.

The spectrochemical series is given in the IB data booklet in section 15. A list of polydentate ligands is given in the data booklet in section 16. Students are not expected to know the different splitting patterns and their relation to the coordination number. Only the splitting of the 3-d orbitals in an octahedral crystal field is required.

Colored Ions:

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Visible Spectrum:

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Light:

D Sublevel Splits:

Energy Level Splits1.Nuclear Charge and Identity of Central Ion

2.Charge

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Nomen:_________________________________________ Dies:__________________IB Chemistry Year 1 HL Unit 2: Periodicity (Topics 3 and 13) Classwork_________________________________________________________________________________________________Density

3.Geometry

4.Number of d electrons and oxidation number

Spectrochemical series:

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Let’s Practice

State the formula and the shape of the complex ion formed in the following reactions.(a) Some iron metal is dissolved in sulfuric acid and then left exposed to air until a yellow solution is formed.(b) Concentrated hydrochloric acid is added to aqueous copper sulfate solution to form a yellow solution.(c) A small volume of sodium chloride is added to aqueous silver nitrate solution. The white precipitate dissolves to form a colourless solution when ammonia solution is added.

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