Atom economy - Study guides, Revision notes & Summaries

2 OCR 2023 SECTION A You should spend a maximum of 25 minutes on this section. Write your answer to each question in the box provided. 1 Which statement explains the trend in boiling points down the halogens group? A Covalent bonds become stronger. B Induced dipole–dipole interactions (London forces) become stronger. C Ionic bonds become stronger. D Permanent dipole–dipole interactions become stronger. Your answer [1] 2 A hydrocarbon contains 85.71% carbon by mass. What is the em...

AQA AS CHEMISTRY 7404/2 Paper 2 Organic and Physical Chemistry Question Paper + Mark scheme [MERGED] June 2022 *JUN* IB/M/Jun22/E7 7404/2 For Examiner’s Use Question Mark 1 2 3 4 5 6 7 Section B TOTAL Time allowed: 1 hour 30 minutes Materials For this paper you must have: • the Periodic Table/Data Sheet, provided as an insert (enclosed) • a ruler with millimetre measurements • a scientific calculator, which you are expected to use where appropriate. Instructions...

AQA CHEMISTRY A LEVEL WITH COMPLETE SOLUTIONS covalent bond - ANSWER-a shared pair of electrons between non-metal elements co-ordinate bond - ANSWER-a shared pair of electrons where both electrons are supplied by one atom repulsion in shapes of molecules - ANSWER-Lone pair-lone pair > lone pair-bonding pair > bonding pair-bonding pair electronegativity - ANSWER-the power of an atom to attract the pair of electrons in a covalent bond hess' law - ANSWER-Total enthalpy chang...

A LEVEL CHEMISTRY EXAM WITH COMPLETE SOLUTIONS alkali - A type of base that dissolves in water forming hydroxide ions, OH- (aq) ions. alkanes - The homologous series with the general formula: CnH2n+2. alkyl group - An alkane with a hydrogen atom removed, e.g. CH3, C2H5; alkyl groups are often shown as 'R'. amount of substance - The quantity whose unit of the mole. Chemists use 'amount of substance' as a means of counting atoms. anhydrous - A substance that contains no water mo...

Relative atomic mass : The average mass of an atom of an element, relative to 1/12th of the mass of an atom of Carbon-12 Relative molecular mass : Average mass of a molecule compared to 1/12th of the mass of a carbon-12 atom The Avogradro constant : the number of particles in a mole ideal gas equation : pV = nRT empirical formula : the simplest whole number ratio of atoms of each element in a compound 2 percentage atom economy : (Mass of desired product/total mass of reactants) x 1...

Learn all about calculations involving masses with this presentation! Includes mass, moles, concentration, atom economy, percentage yield and Avogadro's constant. Includes some practise questions to test your learning!

AQA CHEMISTRY A LEVEL WITH COMPLETE SOLUTIONS covalent bond - ANSWER-a shared pair of electrons between non-metal elements co-ordinate bond - ANSWER-a shared pair of electrons where both electrons are supplied by one atom repulsion in shapes of molecules - ANSWER-Lone pair-lone pair > lone pair-bonding pair > bonding pair-bonding pair electronegativity - ANSWER-the power of an atom to attract the pair of electrons in a covalent bond hess' law - ANSWER-Total enthalpy chang...

A LEVEL CHEMISTRY EXAM WITH COMPLETE SOLUTIONS   alkali - A type of base that dissolves in water forming hydroxide ions, OH- (aq) ions. alkanes - The homologous series with the general formula: CnH2n+2. alkyl group - An alkane with a hydrogen atom removed, e.g. CH3, C2H5; alkyl groups are often shown as 'R'. amount of substance - The quantity whose unit of the mole. Chemists use 'amount of substance' as a means of counting atoms. anhydrous - A substance tha...

AQA AS level Chemistry exam 2024 questions with 100% correct answers Nucleons - ANSWERS Protons and neutrons Electrons (location) - ANSWERS Surrounding the nucleus Relative mass of an electron - ANSWERS 1/1840 Strong nuclear force - ANSWERS The way protons and neutrons are held together in the nucleus Electrostatic forces - ANSWERS The attraction between protons and electrons that hold them together in the atom Atomic Number (Z) - ANSWERS The number of protons in the nucleus Mass nu...

OCR A Level Chemistry Exam Questions With 100% Correct Answers Acid - answerA species that is a proton donor. activation energy - answerThe minimum amount of kinetic energy that particles need to have in order to react when they collide addition polymer - answerA very long molecular chain formed by repeated addition reactions of many unsaturated alkene molecules (monomers). addition polymerisation - answerThe process in which unsaturated alkene molecules (monomers) add on to a growing po...