The rate equation for a reaction is: rate = k[A]²[B]. Which mechanism is consistent?
: A question regarding the dissolution of CO2cap C cap O sub 2 in water (equilibrium:
: This explored the charges on atoms during an SN2cap S sub cap N 2 a level h2 chemistry 2012 paper 1 answers
The paper used a tough buffer calculation where the pKa was not given directly. You had to derive it from the Ka of ethanoic acid, then apply Henderson-Hasselbalch. The correct answer (D) required precise logarithms.
This involved the selective reduction of a ketone. Sodium borohydride ( NaBH4cap N a cap B cap H sub 4 The rate equation for a reaction is: rate = k[A]²[B]
: Replacements for CFCs must be compounds that do not contain chlorine or bromine. Options A , B , and C were valid halogenoalkane replacements, while D was disqualified as it was not a halogenoalkane. Answer Key Summary (Partial) C Stoichiometry/Organic structure B Ionization Energies B Hydrogen Bonding D Electrochemistry/Electrolysis C Chemical Equilibrium D Selective Reduction B Stereoisomerism B SN2cap S sub cap N 2 D CFC Replacements
: This compared hydrogen bonding in HFcap H cap F H2Ocap H sub 2 cap O is more electronegative than H2Ocap H sub 2 cap O You had to derive it from the Ka
Since I cannot reproduce the entire 40-question answer key (copyrighted material), I will instead:
C ( Al2Cl6 ) Why students get it wrong: Many pick AlCl3 because Al is electron-deficient. However, in the gaseous phase, AlCl3 dimerizes to form Al2Cl6 . In this dimer, one chlorine atom donates a lone pair to the empty p-orbital of an adjacent aluminum, forming a dative bond (coordinate bond). SiO2 has polar covalent bonds, NaCl is ionic.
This question compared the boiling points of water ( H2Ocap H sub 2 cap O ) and hydrogen fluoride ( HFcap H cap F is more electronegative than , water has a higher boiling point because each H2Ocap H sub 2 cap O molecule can form an average of two hydrogen bonds , whereas HFcap H cap F forms only one on average. Section 2: Energetics & Reaction Kinetics
, the answers for the 40 multiple-choice questions are provided below. This paper covers core concepts including atomic structure, chemical bonding, energetics, kinetics, and organic chemistry. 2012 H2 Chemistry Paper 1 Answer Key