G2 Science Chemistry Course check

Learning objectives

• describe neutrality and relative acidity and alkalinity, in terms of — relative H+ and OH– ion concentrations,
• describe the reaction between hydrogen ions and hydroxide ions to produce water, H+ + OH– → H2O, as neutralisation
• describe the solid, liquid and gaseous states of matter and explain their interconversion in terms of the kinetic particle theory and of the energy changes involved.
• describe neutrality and relative acidity and alkalinity, in terms of — colour in Universal Indicator, and
• describe the carbon cycle in simple terms, to include — how the carbon cycle regulates the amount of carbon dioxide in the atmosphere (see also 8.1(d))
• describe the alkenes as a homologous series of unsaturated hydrocarbons with the general formula CnH2n
• describe the pollution problems caused by the disposal of non-biodegradable plastics
• draw the structures of unbranched alkenes, C2 and C3, and name the unbranched alkenes ethene and propene
• describe neutrality and relative acidity and alkalinity, in terms of — the pH scale (calculation of pH from hydrogen ion concentration is not required)
• describe methods of separation and purification for the components of mixtures, to include: — use of a suitable solvent, filtration and crystallisation or evaporation
• describe lithium, sodium and potassium in Group 1 (the alkali metals) as a collection of relatively soft, low density metals showing a trend in melting point and in their reaction with water
• describe the difference between saturated and unsaturated hydrocarbons from their molecular structures and by using aqueous bromine
• perform calculations involving the relationship between the amount of substances in moles, mass and molar mass (calculations of stoichiometric reacting masses and volumes of gases are not required).
• define the term isotopes
• describe, with the aid of diagrams, the structure of an atom as consisting of protons and neutrons (nucleons) in the nucleus and electrons arranged in shells (energy levels) (knowledge of s, p, d and f classification is not required; a copy of the Periodic Table will be available in the examination)
• describe two methods of recycling plastics as — physical method (exemplified by melting small pieces of poly(ethene) waste into pellets)
• describe a homologous series as a group of compounds with a general formula, similar chemical properties and showing a gradation in physical properties as a result of increase in the size and mass of the molecules, e.g. melting and boiling points; viscosity
• interpret and evaluate experimental data and observations
• describe the manufacture of alkenes and hydrogen by cracking hydrocarbons and recognise that cracking is essential to match the demand for fractions containing smaller molecules from the refinery process
• deduce the structure of the addition polymer product from a given monomer and vice versa
• deduce the arrangement of electrons in other covalent molecules
• describe the volume composition of gases present in dry air as being approximately 78% nitrogen, 21% oxygen and the remainder being noble gases (with argon as the main constituent) and carbon dioxide
• suggest suitable separation and purification methods, given information about the substances involved in the following types of mixtures: — solid-liquid
• describe how the position of an element in the Periodic Table is related to proton number and electronic configuration
• describe the characteristic properties of acids as in reactions with metals, bases and carbonates to form salts (description of the preparation of pure salts is not required)
• describe the general physical properties of metals as solids having high melting and boiling points, malleable and good conductors of heat and electricity
• define relative molecular mass, Mr, and calculate relative molecular mass (and relative formula mass) as the sum of relative atomic masses
• describe the alkanes as a homologous series of saturated hydrocarbons with the general formula CnH2n+2
• describe the formation of poly(ethene) as an example of addition polymerisation of ethene as the monomer (see also 8.2(i))
• describe the lack of reactivity of the elements in Group 18 (the noble gases) in terms of their electronic configurations.
• relate the physical properties (including electrical property) of ionic compounds to their lattice structure.
• describe, including the use of ‘dot-and-cross’ diagrams, the formation of ionic bonds between metals and non-metals, e.g. NaCl; MgCl2
• define relative atomic mass, Ar
• state the relative charges and approximate relative masses of a proton, a neutron and an electron
• relate the physical properties (including electrical property) of covalent substances to their structure and bonding.
• describe the meanings of the terms acid and alkali in terms of the ions they produce in aqueous solution and their effects on Universal Indicator
• state that carbon dioxide and methane are greenhouse gases and may contribute to global warming; give the sources of these gases and describe the potential effects of increased levels of these greenhouse gases, including more extreme weather events and melting of polar ice.
• deduce the formulae of simple compounds from the relative numbers of atoms present and vice versa
• explain the similarities between the elements in the same group of the Periodic Table in terms of their electronic configuration
• describe methods of separation and purification for the components of mixtures, to include: — distillation and fractional distillation (see also 8.1(b))
• select and use techniques, apparatus and materials
• deduce the numbers of protons, neutrons and electrons in atoms and ions given proton and nucleon numbers.
• discuss some of the effects of these pollutants on health and on the environment — the toxic nature of carbon monoxide
• describe the change from metallic to non-metallic character from left to right across a period of the Periodic Table
• construct chemical equations, with state symbols, including ionic equations.
• deduce the order of reactivity from a given set of experimental results
• describe biofuel (exemplified by bioethanol from sugarcane) as a renewable alternative to natural gas and crude oil
• state the symbols of the elements and formulae of the compounds mentioned in the syllabus
• describe the reactions of alkenes (exemplified by ethene) in terms of combustion, polymerisation (see also 8.3(b)) and the addition with bromine and hydrogen
• predict the properties of elements in Group 1 and Group 17 using the Periodic Table.
• name some common atmospheric pollutants, e.g. carbon monoxide; methane; nitrogen oxides (NO and NO2); ozone; sulfur dioxide; unburned hydrocarbons
• name natural gas, mainly methane, and crude oil as non-renewable sources of energy
• describe the relationship between number of outer (valence) electrons and metallic/non-metallic character
• classify oxides as acidic, basic, amphoteric or neutral based on metallic/non-metallic character.
• draw the structures of unbranched alkanes, C1 to C3, and name the unbranched alkanes methane to propane
• deduce the formulae of ionic compounds from the charges on the ions present and vice versa
• describe tests to identify the following gases: carbon dioxide (using limewater); hydrogen (using a burning splint); oxygen (using a glowing splint).
• describe two methods of recycling plastics as — chemical method (exemplified by cracking of plastic waste into fuel)
• describe the essential conditions for the corrosion (rusting) of iron as the presence of oxygen and water; prevention of rusting can be achieved by placing a barrier around the metal, e.g. painting; greasing; plastic coating.
• describe the Periodic Table as an arrangement of the elements in the order of increasing proton (atomic) number
• describe alkanes (exemplified by methane) as being generally unreactive except in terms of combustion and substitution by chlorine
• describe the formation of ions by electron loss/gain and that these ions usually have the electronic configuration of a noble gas
• state the meaning of polyunsaturated when applied to food products
• discuss some of the effects of these pollutants on health and on the environment — the role of nitrogen dioxide and sulfur dioxide in the formation of ‘acid rain’ and its effects on respiration and buildings
• interpret chemical equations with state symbols
• evaluate methods and suggest possible improvements.
• discuss the social, economic and environmental issues of recycling plastics.
• describe the importance of controlling the pH in soils and how excess acidity can be treated using calcium hydroxide
• describe the carbon cycle in simple terms, to include — the processes of combustion, respiration and photosynthesis
• describe the formation of a covalent bond by the sharing of a pair of electrons and that the atoms in the molecules usually have the electronic configuration of a noble gas
• name appropriate apparatus for the measurement of time, temperature, mass and volume; including burettes, pipettes, measuring cylinders and gas syringes
• describe an alloy as a mixture of a metal with another element, e.g. brass; stainless steel
• describe methods of separation and purification for the components of mixtures, to include: — paper chromatography
• describe the manufacture of margarine by the addition of hydrogen to unsaturated vegetable oils to form a solid product.
• place in order of reactivity calcium, copper, (hydrogen), iron, lead, magnesium, potassium, silver, sodium and zinc by reference to the reactions, if any, of the metals with water, steam and dilute hydrochloric acid
• interpret and use nuclide notations such as ¹²₆C
• describe the ease of obtaining metals from their ores by relating the elements to their positions in the reactivity series
• describe, using ‘dot-and-cross’ diagrams, the formation of covalent bonds between non-metallic elements, e.g. H2; O2; H2O; CH4; CO2
• suggest suitable apparatus, given relevant information, for a variety of simple experiments, including collection of gases.
• interpret paper chromatograms including comparison with ‘known’ samples (the use of Rf values is not required)
• deduce from given melting point and boiling point data the identities of substances and their purity.
• state the sources of these pollutants as — sulfur dioxide from volcanoes and combustion of fossil fuels
• suggest suitable separation and purification methods, given information about the substances involved in the following types of mixtures: — liquid-liquid (miscible)
• define proton (atomic) number and nucleon (mass) number
• state the sources of these pollutants as — carbon monoxide from incomplete combustion of carbon-containing substances
• describe crude oil as a mixture of hydrocarbons and its separation by fractional distillation to yield fractions which have competing uses as fuels and as a source of chemicals (see also 1.2(a))
• describe the differences between elements, compounds and mixtures
• suggest suitable separation and purification methods, given information about the substances involved in the following types of mixtures: — solid-solid
• describe the characteristic properties of bases in reactions with acids and with ammonium salts
• describe polymers as large molecules built up from small units (monomers), different polymers having different units
• take readings and record observations
• identify representations of metals and alloys from diagrams of structures.
• describe how biofuel, when compared to fossil fuels, is more environmentally sustainable in terms of the offset in carbon dioxide emission during burning by that taken in during plant growth (see also 9(e)).
• describe chlorine, bromine and iodine in Group 17 (the halogens) as a collection of diatomic non- metals showing a trend in colour, state and their displacement reactions with solutions of other halide ions
• state the sources of these pollutants as — nitrogen oxides from lightning activity and internal combustion engines
• state some uses of poly(ethene) as a typical plastic, e.g. plastic bags; clingfilm