AQA A LEVEL CHEMISTRY PAPER 2 (2025)
EXAM QUESTIONS AND ALL CORRECT
ANSWERS.
Relative /atomic /mass /(Ar) /- /ANS-
Average
/mass /of /an /atom /compared /with /one /twelth /of /the /mass /of /an /atom /of /carbon /12
Electronegativity /- /ANS-
Power /of /an /atom /to /attract /the /pair /of /electrons /in /a /covalent /bond
Standard /enthalpy /of /combustion /- /ANS-
Enthalpy
/change
/when /
1
/mole
/of /
a
/substance
/burns /completely /in /oxygen /under /standard /conditions /with /all /reactants /and /products /being
/in /their /standard /state
Standard /enthalpy /of /formation /- /ANS-
Enthalpy
/change
/when /
1
/mole
/of /
a /compound /is /formed /from /it's /elements /under /standard /conditions /in /their /standard /states
Mean /bond /enthalpy /- /ANS-
The /average /energy /needed /to /break /a /certain /type /of /bond /over /a /range /of /compounds
, Activation /energy /- /ANS-Minimum /energy /required /for /colliding /molecules /to /react
Maxwell-Boltzmann /distribution /x /and /y /axes /- /ANS-x: /Energy
y: /fraction/number /of /molecules
What /happens /to /the /Maxwell-Boltzmann /curve /when /temperature /increases /- /ANS-
Moves /down /and /to /the /right
Rate /of /reaction /- /ANS-Rate /at /which /product /formed/reactant /used /up
Order /of /reaction /- /ANS-
Power /to /which /the /concentration /of /a /species /is /raised /in /the /rate /equation
rearrange /k=Ae^-Ea/Rt /- /ANS-lnk=-Ea/Rt+lnA
Conditions /for /thermal /cracking /- /ANS-High /temperature /and /high /pressure
Products /of /thermal /cracking /- /ANS-High /% /of /alkenes
Conditions /for /catalytic /cracking /- /ANS-
High /temperature /,slight /pressure /and /in /the /presence /of /a /zeolite /catalyst
Products /of /catalytic /cracking /- /ANS-Motor /fuels /and /aromatic /hydrocarbons
Why /do /we /crack /alkanes? /- /ANS-
Smaller /alkanes/alkenes /generally /more /useful /than /longer /chain /ones
Equation /for /complete /combustion /of /alkanes /- /ANS-
alkane /+ /oxygen /> /carbon /dioxide /+ /water
EXAM QUESTIONS AND ALL CORRECT
ANSWERS.
Relative /atomic /mass /(Ar) /- /ANS-
Average
/mass /of /an /atom /compared /with /one /twelth /of /the /mass /of /an /atom /of /carbon /12
Electronegativity /- /ANS-
Power /of /an /atom /to /attract /the /pair /of /electrons /in /a /covalent /bond
Standard /enthalpy /of /combustion /- /ANS-
Enthalpy
/change
/when /
1
/mole
/of /
a
/substance
/burns /completely /in /oxygen /under /standard /conditions /with /all /reactants /and /products /being
/in /their /standard /state
Standard /enthalpy /of /formation /- /ANS-
Enthalpy
/change
/when /
1
/mole
/of /
a /compound /is /formed /from /it's /elements /under /standard /conditions /in /their /standard /states
Mean /bond /enthalpy /- /ANS-
The /average /energy /needed /to /break /a /certain /type /of /bond /over /a /range /of /compounds
, Activation /energy /- /ANS-Minimum /energy /required /for /colliding /molecules /to /react
Maxwell-Boltzmann /distribution /x /and /y /axes /- /ANS-x: /Energy
y: /fraction/number /of /molecules
What /happens /to /the /Maxwell-Boltzmann /curve /when /temperature /increases /- /ANS-
Moves /down /and /to /the /right
Rate /of /reaction /- /ANS-Rate /at /which /product /formed/reactant /used /up
Order /of /reaction /- /ANS-
Power /to /which /the /concentration /of /a /species /is /raised /in /the /rate /equation
rearrange /k=Ae^-Ea/Rt /- /ANS-lnk=-Ea/Rt+lnA
Conditions /for /thermal /cracking /- /ANS-High /temperature /and /high /pressure
Products /of /thermal /cracking /- /ANS-High /% /of /alkenes
Conditions /for /catalytic /cracking /- /ANS-
High /temperature /,slight /pressure /and /in /the /presence /of /a /zeolite /catalyst
Products /of /catalytic /cracking /- /ANS-Motor /fuels /and /aromatic /hydrocarbons
Why /do /we /crack /alkanes? /- /ANS-
Smaller /alkanes/alkenes /generally /more /useful /than /longer /chain /ones
Equation /for /complete /combustion /of /alkanes /- /ANS-
alkane /+ /oxygen /> /carbon /dioxide /+ /water
