AQA A LEVEL CHEMISTRY PAPER 1 WITH CORRECT ANSWERS

AQA A LEVEL CHEMISTRY PAPER 1
WITH CORRECT ANSWERS

TOF steps - correct answer
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1) ionisation
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2) acceleration
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3) ion drift
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4) detection
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5) analysis
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Electron impact - correct answerSample vaporised and electron gun fires high energy electrons at it which
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knock off 1 electron from each particle, making them 1+ ions
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NB- can knock off more than one e or break molecular ion
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electrospray ionization - correct answerSample dissolved in volatile solvent then injected through needle to
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give fine mist which is attached to positive end of high voltage power supply, particles gain proton
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NB- Mr of substance is actually one less than shown due to extra H+
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Acceleration (TOF) - correct answerpositive ions accelerated using electric field so they all have the same
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kinetic energy
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Ion drift (TOF) - correct answerparticles with small mass have larger velocity do ions start to separate with
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lightest ions reaching detector first
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Detection (TOF) - correct answerpositive ions hit negatively charged plate and gain an electron which forms a
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current, the larger the current the higher the abundance
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, Analysis (TOF) - correct answer-computer uses data to produce mass spectrum which shows mass m / charge z
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ratio
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-mr or ar is furthest right peak (small peaks larger than mr are due to isotopes)
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-may be large peaks at lower mr due to fragmentation
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Electron spin - correct answerProperty of electron (CW or ACW) l l l l l l l l l




Represented by up and down arrows l l l l l




Orbitals - correct answerDefined regions of space around nucleus where electrons most likely to be found,
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each orbital holds 2 electrons
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Hund's Rule - correct answerElectrons prefer to occupy orbitals on their own and only pair up when no empty
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or bait ask of same energy are available
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Electron configuration - correct answer1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d10
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exceptions to electron configuration - correct answerchromium and copper, only take one electron in 4s
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orbital
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Why does ionization energy decrease down a group? - correct answerAtoms get bigger so electrons further
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away from nucleus, greater shielding
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Why does ionization energy increase across a period? - correct answerAtoms get smaller, nuclear charge
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increases, similar shielding
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Dip in ionisation energy groups 2-3 - correct answerElectrons take up higher orbital (s to p) which makes
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ionisation energy lower as higher orbitals have higher energy
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