N5 Chemistry Definitions Quiz

formula mass = The sum of the relative atomic masses of all the atoms present in a formula fraction = A group of hydrocarbons with boiling points within a given range obtained from crude oil by fractional distillation fuel = A substance which burns to produce energy functional group = A group of atoms with characteristic chemical activity, e.g. carboxyl group -COOH

fossil fuel = Coal, crude oil, natural gas glycerol = An alcohol with three -OH groups in each molecule, CH2OHCHOHCH2OH greenhouse gas = Carbon dioxide, CO2 halogens = Reactive non-metals in group 7 of the Periodic Table (F, Cl, Br, I, At)

fractional distillation = A means of separating crude oil into groups of hydrocarbons with similar boiling points (fractions) group ion = One which contains more than one kind of atom, e.g. the ammonium ion, NH4+ homologous series = A group of chemically similar compounds which can be represented by a general formula. Physical properties change gradually through the series, e.g. the alkanes hydrocarbon = A compound that contains carbon and hydrogen only

<p>G general formula = One from which the molecular formula for any member of a homologous series can be deduced, e.g. CnH2n+2 for the alkanes group = A column of elements in the Periodic Table H halogens = Reactive non-metals in group 7 of the Periodic Table (F, Cl, Br, I, At) hydroxyl group = The group -OH found, for example, in water and alkanols</p> Signup and view all the answers

<p>element = A substance which cannot be broken down into simpler substances by chemical means. All of its atoms have the same atomic number. end point = The point of a volumetric titration when the reaction is complete, which is shown by a colour change in a suitable indicator. endothermic reaction = One in which heat energy is taken in from the surroundings causing a decrease in temperature. evaporation = The process of turning a liquid into a vapour (gas), usually by heating.</p> Signup and view all the answers

<p>exothermic reaction = One in which heat energy is given out to the surroundings causing an increase in temperature. fermentation = The breakdown of glucose to produce ethanol and carbon dioxide catalysed by enzymes in yeast. (Can be applied to the similar breakdown of other organic molecules.) filtrate = The liquid which passes through filter paper during filtration. filtration = The separation of an insoluble solid from a liquid by passage through filter paper.</p> Signup and view all the answers

<p>finite = Limited. flame = A region where gases combine producing heat and light energy. flammable = Describes a substance that is easily set on fire. formula = A simple chemical formula for a molecular substance usually indicates the number of atoms of each element in a molecule, e.g. CO2.</p> Signup and view all the answers

<p>formulae equation = Equation which gives chemical symbols and formulae for reactants and products. enzyme = A biological catalyst. CSS = Styling web pages SQL = Database queries</p> Signup and view all the answers

<p>Universal indicator solution = A solution containing several indicators used to give approximate pH Unsaturated hydrocarbon = Contains at least one carbon-to-carbon double covalent bond Valency = Number indicating the 'combining power' of atoms or ions Vaporisation = Process in which a liquid changes into a gas</p> Signup and view all the answers

<p>Variable = Something that can be changed in a chemical reaction Viscosity = Description of how 'thick' a liquid is Volatile = Describes a liquid with a low boiling point that easily evaporates Volumetric titration = Experiment where volumes of reacting liquids are measured</p> Signup and view all the answers

<p>Universal indicator solution = Gives a range of colors depending on pH Valency = Indicates the 'combining power' of atoms or ions Viscosity = Engine oil is 'thicker' than petrol Word equation = Provides only the names of reactants and products</p> Signup and view all the answers

<p>molecule = A group of atoms held together by covalent bonds. neutral solution = One in which the concentrations of H+(aq) and OH-(aq) ions are equal. neutron = A particle found in the nucleus of an atom. It has the same mass as a proton but no charge. oxidation reaction = One in which electrons are lost.</p> Signup and view all the answers

<p>mixture = Two or more substances mixed together but not chemically joined, e.g. air and sea water. molecular formula = Formula which shows the number of atoms of different elements present in one molecule of a substance. N natural gas = Gas obtained from underground deposits, which consists mainly of methane. nucleus = The extremely small centre of an atom where the protons and neutrons are found.</p> Signup and view all the answers

<p>metallic bond = The electrostatic force of attraction between positive ions in a metallic lattice and the delocalised electrons within the structure. monomer = Relatively small molecules which can join together to produce a very large molecule (a polymer) by a process called polymerisation. noble gases = Very unreactive gases in group 0 of the Periodic Table (He, Ne, Ar, Kr, Xe, Rn). non-metals = Non-conducting elements (except carbon as graphite) found on the right of the Periodic Table.</p> Signup and view all the answers

<p>mole = A formula mass expressed in grams. neutralisation reaction = A reaction of acids with bases in which the pH of a solution moves towards 7. neutron = A particle found in the nucleus of an atom. It has the same mass as a proton but no charge. oxidation reaction = One in which electrons are lost.</p> Signup and view all the answers

<p>mixture = Two or more substances mixed together but not chemically joined, e.g. air and sea water. molecular formula = Formula which shows the number of atoms of different elements present in one molecule of a substance. non-metals = Non-conducting elements (except carbon as graphite) found on the right of the Periodic Table. nuclear reaction = A reaction involving changes in atomic nuclei.</p> Signup and view all the answers

<p>metallic bond = The electrostatic force of attraction between positive ions in a metallic lattice and the delocalised electrons within the structure. molecule = A group of atoms held together by covalent bonds. N natural gas = Gas obtained from underground deposits, which consists mainly of methane. When found in association with crude oil it contains appreciable quantities of other hydrocarbons such as ethane, propane, and butane. neutron = A particle found in the nucleus of an atom. It has the same mass as a proton but no charge.</p> Signup and view all the answers

<p>Isotopic mass = The average of the mass numbers of an element's isotopes taking into account the proportions of each Renewable energy source = One which can be renewed and will not therefore run out in the foreseeable future Residue = The solid left behind in the filter paper after filtration Saturated solution = A solution in which no more solute will dissolve at a given temperature</p> Signup and view all the answers

<p>Salt = A compound in which the hydrogen ions of an acid have been replaced by metal ions or ammonium ions Solute = A substance that dissolves in a liquid Solvent = A liquid in which a substance dissolves State symbols = Symbols used to indicate the state of a substance or species: (s) = solid; (l) = liquid; (g) = gas; (aq) = aqueous (dissolved in water)</p> Signup and view all the answers

<p>Spectator ion = An ion which is present in a reaction mixture but takes no part in the reaction Standard solution = One whose concentration is known accurately Structural formula = One which shows the arrangement of atoms in a molecule or ion. A full structural formula shows all of the bonds. Thermoplastic = A plastic which softens on heating and can be reshaped, e.g. PVC and polythene</p> Signup and view all the answers

<p>Thermosetting plastic = One which does not soften on heating, e.g. Bakelite and formica Titration = See volumetric titration Toxic = Poisonous</p> Signup and view all the answers