Unit 1: Structure, Bonding and Introduction to Organic Chemistry:

Unit 1: Structure, Bonding and Introduction to Organic Chemistry:

Topics:

Topic 1, Formulae, Equations and Amount of Substance:

1.1: Know the terms 'atom', 'element', 'ion', 'molecule', 'compound', 'empirical formula' and 'molecular formula'.
1.2: Know that the mole (mol) is the unit for the amount of a substance and be able to perform calculations using the Avogadro constant, L (6.02 x 10²³ mol^-1)
1.3: Write balanced full and ionic equations, including state symbols, for chemical reactions
1.4: Understand the terms:

1.5: Calculate the concentration of a solution in mol dm⁻³ and g dm⁻³ Titration calculations are not required at this stage.
1.6: Be able to use experimental data to calculate empirical and molecular formulae
1.7: Be able to use chemical equations to calculate reacting masses and vice versa, using the concepts of amount of substance and molar mass
1.8: Be able to use chemical equations to calculate volumes of gases and vice versa, using:

(i) the concepts of amount of substance
(ii) the molar volume of gases
(iii) the expression pV = nRT for gases and volatile liquid

1.9: Be able to calculate percentage yields and percentage atom economies (by mass) in laboratory and industrial processes, using chemical equations and experimental results Atom economy = molar mass of the desired product × 100% sum of the molar masses of all products.
1.10: Be able to determine a formula or confirm an equation by experiment, including evaluation of the data
1.11: CORE PRACTICAL 1 Measurement of the molar volume of a gas.
1.12: Be able to relate ionic and full equations, with state symbols, to observations from simple test-tube experiments, to include:

(i) displacement reactions
(ii) typical reactions of acids
(iii) precipitation reactions

Topic 2, Atomic Structure and the Periodic Table:

2.1: know the structure of an atom in terms of electrons, protons and neutrons
2.2: know the relative mass and charge of protons, neutrons and electrons
2.3: know what is meant by the terms ‘atomic (proton) number’ and ‘mass number’
2.4: be able to use the atomic number and the mass number to determine the number of
each type of subatomic particle in an atom or ion
2.5: understand the term ‘isotope’
2.6: understand the basic principles of a mass spectrometer and be able to analyse and
interpret mass spectra to:

(i) deduce the isotopic composition of a sample of an element
(ii) calculate the relative atomic mass of an element from relative abundances of isotopes and vice versa

(iii) determine the relative molecular mass of a molecule, and hence identify molecules in a sample
(iv) understand that ions in a mass spectrometer may have a 2⁺ charge

2.7: be able to predict mass spectra, including relative peak heights, for diatomic
molecules, including chlorine, given the isotopic abundances
2.8: be able to define first, second and third ionisation energies and understand that all
ionisation energies are endothermic
2.9: know that an orbital is a region within an atom that can hold up to two electrons
with opposite spins
2.10 understand how ionisation energies are influenced by the number of protons in the
nucleus, the electron shielding and the sub-shell from which the electron is removed
2.11: know that ideas about electronic structure developed from:

(i) an understanding that successive ionisation energies provide evidence for the existence of quantum shells and the group to which the element belongs
(ii) an understanding that the first ionisation energy of successive elements provides evidence for electron sub-shells

2.12: be able to describe the shapes of s and p orbitals
2.13: know that orbitals in sub-shells:

(i) each take a single electron before pairing up
(ii) pair up with two electrons of opposite spin

2.14: be able to predict the electronic configuration of atoms of the elements from
hydrogen to krypton inclusive and their ions, using s, p, d notation and electron-inboxes
notation
2.15: understand that electronic configuration determines the chemical properties of
an element
2.16: know that the Periodic Table is divided into blocks, such as s, p and d, and know the
number of electrons that can occupy s, p and d sub-shells in the first four quantum
shells
2.17: be able to represent data, in a graphical form (including the use of logarithms of
first ionisation energies on a graph) for elements 1 to 36 and hence explain the
meaning of the term ‘periodic property’
2.18: be able to explain:

(i) the trends in melting and boiling temperatures of the elements of Periods 2 and 3 of the Periodic Table in terms of the structure of the element and the bonding between its atoms or molecules
(ii) the general increase and the specific trends in ionisation energy of the elements across Periods 2 and 3 of the Periodic Table
(iii) the decrease in first ionisation energy down a group

Topic 3, Bonding and Structure:

3A: Ionic bonding:

3.1 know and be able to interpret evidence for the existence of ions, limited to physical properties of ionic compounds, electron density maps and the migration of ions
3.2 be able to describe the formation of ions in terms of loss or gain of electrons
3.3 be able to draw dot-and-cross diagrams to show electrons in cations and anions
3.4 be able to describe ionic crystals as giant lattices of ions
3.5 know that ionic bonding is the result of strong net electrostatic attraction between ions
3.6 understand the effects of ionic radius and ionic charge on the strength of
ionic bonding
3.7 understand reasons for the trends in ionic radii down a group in the Periodic Table, and for a set of isoelectronic ions, including N₃⁻ to Al₃⁺
3.8 understand the meaning of the term ‘polarisation’ as applied to ions
3.9 understand that the polarising power of a cation depends on its radius and charge, and the polarisability of an anion also depends on its radius and charge
Further suggested practical:

The migration of ions in a U-tube using copper(II) chromate solution or on a microscope slide using potassium manganate(VII) crystals

3B: Covalent bonding:

3.10 understand that covalent bonding is the strong electrostatic attraction between two nuclei and the shared pair of electrons between them, based on the evidence:

(i) the physical properties of giant atomic structures
(ii) electron density maps for simple molecules

3.11 be able to draw dot-and-cross diagrams to show electrons in covalent substances, including:

(i) molecules with single, double and triple bonds
(ii) species with dative covalent (coordinate) bonds, including Al₂Cl₆ and the ammonium ion

3.12 be able to describe the different structures formed by giant lattices of carbon atoms, including graphite, diamond and graphene, and discuss the applications of each
3.13 understand the meaning of the term ‘electronegativity’ as applied to atoms in a covalent bond
3.14 know that ionic and covalent bonding are the extremes of a continuum of bonding type and be able to explain this in terms of electronegativity differences, leading to bond polarity in bonds and molecules, and to ionic bonding if the electronegativity is large enough
3.15 be able to distinguish between polar bonds and polar molecules and predict whether or not a given molecule is likely to be polar
Further suggested practical
Determine the effect of an electrostatic force on jets of liquids (water, ethanol and cyclohexane) and use the results to determine whether the molecules are polar or non-polar

3C: Shapes of molecules:

3.16 understand the principles of the electron-pair repulsion theory, used to interpret and predict the shapes of simple molecules and ions
3.17 understand the terms ‘bond length’ and ‘bond angle’
3.18 know and be able to explain the shapes of, and bond angles in, BeCl₂, BCl₃, CH₄, NH₃, NH+₄, H₂O, CO₂, gaseous PCl₅ , SF₆ and C₂H₄
3.19 be able to apply the electron-pair repulsion theory to predict the shapes of, and bond angles in, molecules and ions analogous to those in 3.18

3D: Metallic bonding:

3.20 understand that metals consist of giant lattices of metal ions in a sea of delocalised electrons
3.21 know that metallic bonding is the strong electrostatic attraction between metal ions and the delocalised electrons
3.22 be able to use the models in 3.20 and 3.21 to interpret simple properties of metals, including electrical conductivity and high melting temperature

Topic 4, Introductory Organic Chemistry and Alkanes:

4A: Introduction

4.1 understand the difference between hazard and risk
4.2 understand the hazards associated with organic compounds and why it is necessary to carry out risk assessments when dealing with potentially hazardous materials
4.3 be able to suggest ways in which risks can be reduced and reactions carried out
safely, for example:

(i) working on a smaller scale
(ii) taking precautions specific to the hazard
(iii) using an alternative method that involves less hazardous substances

4.4 understand the concepts of homologous series and functional group
4.5 be able to apply the rules of International Union of Pure and Applied Chemistry (IUPAC) nomenclature to:

(i) name compounds relevant to this specification
(ii) draw these compounds, as they are encountered in the specification, using structural, displayed and skeletal formulae

4.6 be able to classify reactions as addition, substitution, oxidation, reduction or polymerisation
4.7 understand that bond breaking can be:

(i) homolytic, to produce free radicals
(ii) heterolytic, to produce ions

4.8 know definitions of the terms ‘free radical’ and ‘electrophile’

4B: Alkanes

4.9 know the general formula of alkanes and cycloalkanes, and understand that they are hydrocarbons (compounds of carbon and hydrogen only) which are saturated (contain single bonds only)
4.10 understand the term ‘structural isomerism’ and be able to draw the structural isomers of organic molecules, given their molecular formula
4.11 be able to draw and name the structural isomers of alkanes and cycloalkanes with up to six carbon atoms
4.12 know that alkanes are used as fuels and obtained from the fractional distillation, cracking and reforming of crude oil, and be able to write equations for these reactions
4.13 know that pollutants, including carbon monoxide, oxides of nitrogen and sulfur, carbon particulates and unburned hydrocarbons, are emitted during the combustion of alkane fuels
4.14 understand the problems arising from pollutants from the combustion of alkane fuels, limited to the toxicity of carbon monoxide and why it is toxic, and the acidity of oxides of nitrogen and sulfur
4.15 be able to discuss the reasons for developing alternative fuels in terms of sustainability and reducing emissions, including the emission of CO₂ and its relationship to climate change
4.16 be able to apply the concept of carbon neutrality to different fuels, such as petrol, bioethanol and hydrogen
4.17 understand the reactions of alkanes with:

(i) oxygen in the air (combustion)
(ii) halogens

4.18 understand the mechanism of the free radical substitution reaction between an alkane and a halogen:

(i) using free radicals, which are species with an unpaired electron, represented by a single dot
(ii) showing the initiation step of the mechanism, with curly half-arrows for free radical formation
(iii) showing the propagation and termination steps of the mechanism
(iv) having limited use in synthesis because of further substitution reactions

Further suggested practical:

Cracking alkanes by thermal decomposition

Topic 5, Alkenes:

5.1 know the general formula of alkenes and understand that alkenes and cycloalkenes are hydrocarbons which are unsaturated (have a carbon-carbon double bond which consists of a σ bond and a π bond)
5.2 be able to explain geometric isomerism in terms of restricted rotation around a C=C double bond and the nature of the substituents on the carbon atoms
5.3 understand the E–Z naming system for geometric isomers and why it is necessary to use this when the cis- and trans- naming system breaks down
5.4 be able to describe the reactions of alkenes, limited to:

(i) the addition of hydrogen, using a nickel catalyst, to form an alkane
(ii) the addition of halogens to produce a di-substituted halogenoalkane
(iii) the addition of hydrogen halides to produce mono-substituted halogenoalkanes
(iv) the addition of steam, in the presence of an acid catalyst, to produce alcohols
(v) oxidation of the double bond by acidified potassium manganate(VII) to produce a diol

5.5 know the qualitative test for a C=C double bond using bromine or bromine water
5.6 be able to describe the mechanism (including diagrams), giving evidence where possible, of:

(i) the electrophilic addition of bromine and hydrogen bromide to ethene
(ii) the electrophilic addition of hydrogen bromide to propene Use of the curly arrow notation is expected – the curly arrows should start from either a bond or from a lone pair of electrons. Knowledge of the relative stability of primary, secondary and tertiary carbocation intermediates is expected.

5.7 be able to describe the addition polymerisation of alkenes and draw the repeat unit given the monomer, and vice versa
5.8 understand how chemists limit the problems caused by polymer disposal by:

(i) developing biodegradable polymers
(ii) removing toxic waste gases produced by the incineration of polymers

Further suggested practicals:

(i) investigating the difference in reactivity of alkanes and alkenes, including combustion, reaction with bromine water, reaction with acidified potassium manganate(VII)
(ii) preparation of cyclohexene from cyclohexanol
(iii) preparation of limonene from orange peel by steam distillation
(iv) preparation of Perspex® from methyl 2-methylpropenoate

Search This Blog

The Revision Den

Unit 1: Structure, Bonding and Introduction to Organic Chemistry:

Topic 1, Formulae, Equations and Amount of Substance:

Topic 2, Atomic Structure and the Periodic Table:

Topic 3, Bonding and Structure:

3A: Ionic bonding:

3B: Covalent bonding:

3C: Shapes of molecules:

3D: Metallic bonding:

Topic 4, Introductory Organic Chemistry and Alkanes:

4A: Introduction

4B: Alkanes

Topic 5, Alkenes:

Comments

Post a Comment