AQA A LEVEL CHEMISTRY QUESTIONS PERFECTLY SOLVED

AQA A LEVEL CHEMISTRY QUESTIONS
PERFECTLY SOLVED
Relative ytatomic ytmass yt- ytANS--The ytaverage ytmass ytof ytan ytatom ytof ytan ytelement,
ytrelative ytto yt1/12th ytof ytthe ytmass ytof ytan ytatom ytof ytCarbon-12


Relative ytmolecular ytmass yt- ytANS--Average ytmass ytof yta ytmolecule ytcompared ytto
yt1/12th ytof ytthe ytmass ytof yta ytcarbon-12 ytatom


The ytAvogradro ytconstant yt- ytANS--the ytnumber ytof ytparticles ytin yta ytmole

ideal ytgas ytequation yt- ytANS--pV yt= ytnRT

empirical ytformula yt- ytANS--the ytsimplest ytwhole ytnumber ytratio ytof ytatoms ytof yteach
ytelement ytin yta ytcompound


percentage ytatom yteconomy yt- ytANS--(Mass ytof ytdesired ytproduct/total ytmass ytof
ytreactants) ytx yt100


ionic ytbonding yt- ytANS--the ytelectrostatic ytattraction ytbetween ytoppositely ytcharged
ytions ytin yta ytlattice


covalent ytbond yt- ytANS--a ytshared ytpair ytof ytelectrons ytbetween ytnon-metal ytelements

co-ordinate ytbond yt- ytANS--a ytshared ytpair ytof ytelectrons ytwhere ytboth ytelectrons ytare
ytsupplied ytby ytone ytatom


repulsion ytin ytshapes ytof ytmolecules yt- ytANS--Lone ytpair-lone ytpair yt> ytlone ytpair-
bonding ytpair yt> ytbonding ytpair-bonding ytpair

electronegativity yt- ytANS--the ytpower ytof ytan ytatom ytto ytattract ytthe ytpair ytof ytelectrons
ytin yta ytcovalent ytbond


hess' ytlaw yt- ytANS--Total ytenthalpy ytchange ytfor yta ytreaction ytis ytindependent ytof ytthe
ytroute ytchosen


mean ytbond ytenthalpy yt- ytANS--The ytenergy ytrequired ytto ytbreak yta ytcovalent ytbond
ytinto ytgaseous ytatoms ytaveraged ytover ytdifferent ytmolecules


Bonds ytbroken yt- ytbonds ytmade

, activation ytenergy yt- ytANS--The ytminimum ytamount ytof ytenergy ytneeded ytto ytstart yta
ytchemical ytreaction


catalyst yt- ytANS--A ytsubstance ytthat ytincreases ytthe ytrate ytof yta ytchemical ytreaction
ytwithout ytbeing ytchanged ytby ytproviding ytan ytalternative ytreaction ytpathway ytby
ytlowering ytactivation ytenergy


Le ytChatelier's ytprinciple yt- ytANS--When yta ytsystem ytin ytdynamic ytequilibrium ytis
ytsubjected ytto ytchange, ytthe ytposition ytof ytequilibrium ytwill ytshift ytto ytoppose ytthe
ytchange.


oxidising ytagents yt- ytANS--electron ytacceptors

reducing ytagents yt- ytANS--electron ytdonors

Enthalpy ytof ytformation yt- ytANS--Enthalpy ytchange ytwhen ytone ytmole ytof yta
ytcompound ytis ytformed ytfrom ytits ytconstituent ytelements ytunder ytstandard ytconditions
ytin yttheir ytstandard ytstates


Enthalpy ytof ytatomization yt- ytANS--The ytenergy ytrequired ytto ytproduce ytone ytmole ytof
ytgaseous ytatoms ytfrom ytan ytelement ytin ytits ytstandard ytstate


Electron ytaffinity yt- ytANS--the ytenthaply ytchange ytwhen ytone ytmole ytof ytgaseous
ytatoms ytforms ytone ytmole ytof yt-1 ytions


Lattice ytenthalpy ytof ytformation yt- ytANS--Enthalpy ytchange ytwhen ytone ytmole ytof yta
ytsolid ytionic ytcompound ytis ytformed ytfrom ytits ytconstituent ytions ytin ytthe ytgas ytphase


Lattice ytenthalpy ytof ytdissociation yt- ytANS--Energy ytchange ytwhen yt1 ytmol ytof ytan
ytionic ytlattice ytdissociates ytto ytits ytgaseous ytions.


standard ytelectrode ytpotential yt- ytANS--298K yt
100kPa
1.00moldm-3

Electrode ytreactions ytin ytlithium ytcell
yt(positive ytelectrode) yt- ytANS--Li+ yt+ ytCoO2 yt+ yte- yt→ ytLi+[CoO2]-


Electrode ytreactions ytin ytlithium ytcell
yt(negative ytelectrode) yt- ytANS--Li yt→ ytLi+ yt+ yte-


Electrode ytreactions ytin ythydrogen-oxygen ytfuel ytcell ytin ytacidic ytconditions yt
(positive ytelectrode) yt- ytANS--02 yt+ yt4H+ yt+4e- yt-> yt2H20

Electrode ytreactions ytin ythydrogen-oxygen ytfuel ytcell ytin ytacidic ytconditions yt
(negative ytelectrode) yt- ytANS--H2 yt-> yt2H+ yt+ yt2e-