Which series shows the correct order of metallic bond strength from strongest to weakest?

A.  $\mathrm{Na}>\mathrm{K}>\mathrm{Rb}>\mathrm{Mg}$

B.  $\mathrm{Mg}>\mathrm{Rb}>\mathrm{K}>\mathrm{Na}$

C.  $\mathrm{Rb}>\mathrm{K}>\mathrm{Na}>\mathrm{Mg}$

D.  $\mathrm{Mg}>\mathrm{Na}>\mathrm{K}>\mathrm{Rb}$

D

A small majority of candidates could identify the relative strength of metallic bonding amongst group 1 and 2 metals.

What is the formula of the compound formed from Ca²⁺ and PO₄³⁻?

A.  CaPO₄

B.  Ca₃(PO₄)₂

C.  Ca₂(PO₄)₃

D.  Ca(PO₄)₂

B

Which compound contains both ionic and covalent bonds?

A.  CH₃COONa

B.  CH₃COOH

C.  K₂O

D.  CaCl₂

A

What is the formula of magnesium nitride?

A.     MgN

B.     Mg₂N₃

C.     Mg₃N

D.     Mg₃N₂

D

Which compound has the shortest C to O bond?

A.  CH₃CHO

B.  CO

C.  CO₂

D.  C₂H₅OC₂H₅

B

A substance has the following properties:

What is the most probable structure of this substance?

A.     Network covalent

B.     Polar covalent molecule

C.     Ionic lattice

D.     Metallic lattice

A

Which molecule has the weakest nitrogen to nitrogen bond?

A.  N₂

B.  N₂H₂

C.  N₂H₄

D.  

C

A compound consists of the ions Ca²⁺ and PO₄^3–. What are the name and formula of the compound?

D

Which combination corresponds to a strong metallic bond?

B

The concept of charge and ionic radii size on the strength of the bond was answered well, but had the lowest discriminatory index on the paper.

Which compound has the shortest C–N bond?

A. CH₃NH₂

B. (CH₃)₃CNH₂

C. CH₃CN

D. CH₃CHNH

C

The following compounds have similar relative molecular masses. What is the order of increasing boiling point?

A.  CH₃CH₂CH₂OH < CH₃CH₂CHO < CH₃COOH

B.  CH₃CH₂CHO < CH₃CH₂CH₂OH < CH₃COOH

C.  CH₃CH₂CHO < CH₃COOH < CH₃CH₂CH₂OH

D.  CH₃COOH < CH₃CH₂CHO < CH₃CH₂CH₂OH

B

Which combination causes the strength of metallic bonding to increase?

D

A question about factors affecting the strength of metallic bonding answered correctly by 68 % of candidates. The distractors were almost equally chosen by the rest of the candidates.

Which combination would create the strongest ionic bond?

C

Which metal has the strongest metallic bond?

A.     Li

B.     Na

C.     K

D.     Rb

A

Which is correct for all solid ionic compounds?

A.  High volatility

B.  Poor electrical conductivity

C.  Low melting point

D.  Good solubility in water

B

Which alcohol is least soluble in water?

A.  CH₃OH

B.  CH₃CH₂OH

C.  CH₃CH₂CH₂OH

D.  CH₃CH₂CH₂CH₂OH

D

What are the predicted electron domain geometries around the carbon and both nitrogen atoms in urea, (NH₂)₂CO, applying VSEPR theory?

B

Which bonds cause the boiling point of water to be significantly greater than that of hydrogen sulfide?

A.     London (dispersion)

B.     Covalent

C.     Ionic

D.     Hydrogen

D

Which molecule is most polar?

A.  CF₄

B.  CCl₄

C.  CHF₃

D.  CClF₃

C

Question 11 was identified in the G2s as a tricky question, because students could have difficulty resolving the conflict between the greater polarity of the C-Cl bond compared with the C-H bond, and their contrast with the polarity of the C-F bond.) However, 56% of student did identify the correct answer of C.

Which molecule is most polar?

A.  ${\mathrm{CHF}}_3$

B.  ${\mathrm{CF}}_4$

C.  ${\mathrm{CClF}}_3$

D.  ${\mathrm{CCl}}_4$

A

63% of the candidates could identify CHF₃ as more polar than CClF₃. A surprising number selected either CCl₄ or CF₄ as the most polar.

Which combination describes the sulfate(IV) ion, SO₃^2– (also known as sulfite ion)?

D

What is the formula of ammonium phosphate?

A.     (NH₃)₃PO₄

B.     (NH₄)₃PO₄

C.     (NH₄)₂PO₄

D.     (NH₃)₂PO₃

B

What are the strongest intermolecular forces between molecules of propanone, CH₃COCH₃, in the liquid phase?

A.     London (dispersion) forces

B.     Covalent bonding

C.     Hydrogen bonding

D.     Dipole–dipole forces

D

Which describes an ionic compound?

B

Fairly well answered with the most widely held misconception being that ionic compounds conduct electricity in the solid state.

What is the main interaction between liquid CH₄ molecules?

A.  London (dispersion) forces

B.  Dipole–dipole forces

C.  Hydrogen bonding

D.  Covalent bonding

A

56% of the candidates were able to identify London (dispersion) forces as the main interaction between liquid CH₄ molecules. Covalent bonding was the most commonly chosen distractor. Good performance on this question correlated well with candidates who scored well overall.

What is the order of increasing boiling point?

A. CH₃CH₂CH₂CH₃ < CH₃CH(OH)CH₃ < CH₃COCH₃ < CH₃CO₂H

B. CH₃CH₂CH₂CH₃ < CH₃COCH₃ < CH₃CH(OH)CH₃ < CH₃CO₂H

C. CH₃CO₂H < CH₃COCH₃ < CH₃CH(OH)CH₃ < CH₃CH₂CH₂CH₃

D. CH₃CH₂CH₂CH₃ < CH₃COCH₃ < CH₃CO₂H < CH₃CH(OH)CH₃

B

Ranking compounds in order of increasing boiling point proved challenging. There existed a number of misconceptions based on the incorrect answers chosen being close to evenly distributed.

Which substance has a giant covalent structure?

D

How many bonding electrons are there in the urea molecule?

A.     8

B.     16

C.     20

D.     24

B

Which two atoms form the most polar bond?

A.     C and F

B.     C and Cl

C.     Si and F

D.     Si and Cl

C

Which of the following does not react with dilute HCl(aq)?

A.     Na₂CO₃

B.     Cu

C.     Zn

D.     CuO

B

Which compound has hydrogen bonds between its molecules?

A. CH₄

B. CH₄O

C. CH₃Cl

D. CH₂O

B

72 % of the candidates identified CH₄O as having hydrogen bonds between its molecules. The most commonly chosen distractor was CH₂O, the only other option containing oxygen.

How many lone pairs and bonding pairs of electrons surround the central chlorine atom in ClF₂⁺?

D

The compounds shown below have similar relative molecular masses. What is the correct order of increasing boiling point?

A.     CH₃COOH < (CH₃)₂CO < (CH₃)₂CHOH

B.     CH₃COOH < (CH₃)₂CHOH < (CH₃)₂CO

C.     (CH₃)₂CO < CH₃COOH < (CH₃)₂CHOH

D.     (CH₃)₂CO < (CH₃)₂CHOH < CH₃COOH

D

What are the approximate bond angles and structure of crystalline SiO₂?

B

What is the structure and bonding in SiO₂(s)?

A

Which series is in order of increasing boiling point?

A.  CH₂CH₂CH₃OH    CH₃COCH₃         CH₃CH₂CH₃

B.  CH₃CH₂CH₃         CH₃COCH₃          CH₂CH₂CH₃OH

C.  CH₃COCH₃          CH₂CH₂CH₃OH    CH₃CH₂CH₃

D.  CH₃CH₂CH₃         CH₂CH₂CH₃OH    CH₃COCH₃

B

What is the order of increasing boiling point?

A.     C₄H₁₀ < CH₃COOH < CH₃CH₂CHO < CH₃CH₂CH₂OH

B.     C₄H₁₀ < CH₃CH₂CHO < CH₃CH₂CH₂OH < CH₃COOH

C.     CH₃COOH < CH₃CH₂CH₂OH< CH₃CH₂CHO < C₄H₁₀

D.     C₄H₁₀ < CH₃CH₂CH₂OH < CH₃CH₂CHO < CH₃COOH

B

Which molecule is polar?

A.   BeCl₂

B.   BCl₃

C.   NCl₃

D.   CCl₄

C

Which combination correctly describes the geometry of the carbonate ion, ${{\mathrm{CO}}_3}^{2-}$?

C

Identifying correct electron domain and molecular geometries around a central atom was somewhat challenging and answered slighter better by higher scoring candidates.

Between which pair of molecules can hydrogen bonding occur? 

A. CH₄ and H₂O
B. CH₃OCH₃ and CF₄ 
C. CH₄ and HF 
D. CH₃OH and H₂O

D

Which pair of molecules has the same bond angles? 

A. PCl₃ and BCl₃ 

B. SO₂ and CO₂ 

C. H₂O and NH₃ 

D. CCl₄ and SiH₄

D

Which correctly states the strongest intermolecular forces in the compounds below?

B

Which statement best describes the intramolecular bonding in HCN (l)?

A. Electrostatic attractions between H⁺ and CN⁻ ions

B. Hydrogen bonding

C. Van der Waals forces and hydrogen bonding

D. Electrostatic attractions between pairs of electrons and positively charged nuclei

D

The majority of the candidates thought the bonding in HCN is ionic (electrostatic attraction between H⁺ and CN^- ions) rather than covalent. The description of covalent bonding was the second most commonly chosen response.

Which form of carbon is the poorest electrical conductor?

A.     Graphite

B.     Graphene

C.     Diamond

D.     Carbon nanotube

C

What is the molecular geometry and bond angle in the molecular ion NO₃⁻?

B

Which compound has the highest boiling point?

A.   CH₃CHO

B.   CH₃CH₂F

C.   CH₃OCH₃

D.   CH₃CH₂NH₂

D

How does a lithium atom form the most stable ion?

A. The atom gains a proton to form a positive ion.

B. The atom loses a proton to form a negative ion.

C. The atom loses an electron to form a positive ion.

D. The atom gains an electron to form a negative ion.

C

One of the most straight-forward questions on the paper about how lithium forms its most stable ion. It was answered correctly by 87 % of the candidates.

The electronegativity values of four elements are given.

What is the order of increasing polarity of the bonds in the following compounds?

A. CO < OF₂ < NO < CF₄

B. CF₄ < CO < OF₂ < NO

C. NO < OF₂ < CO < CF₄

D. CF₄ < NO < OF₂ < CO

C

Which substance is most likely to be ionic?

D

Which is the correct order based on increasing strength?

A.  covalent bonds < hydrogen bonds < dipole–dipole forces < dispersion forces

B.  dipole–dipole forces < dispersion forces < hydrogen bonds < covalent bonds

C.  dispersion forces < dipole–dipole forces < hydrogen bonds < covalent bonds

D.  dispersion forces < dipole–dipole forces < covalent bonds < hydrogen bonds

C

Which compound contains both ionic and covalent bonds?

A.  $\text{MgO}$

B.  ${\text{CH}}_{\text{2}}{\text{Cl}}_{\text{2}}$

C.  ${\text{CH}}_{\text{3}}\text{COOH}$

D.  $\text{NaOH}$

D

The Lewis structure of methylamine is shown.

What is the molecular geometry around N?

A.  Square planar

B.  Tetrahedral

C.  Trigonal planar

D.  Trigonal pyramidal

D

Which molecule contains an incomplete octet of electrons?

A. NF₃

B. BF₃

C. BrF

D. SF₂

B

66 % of the candidates identified BF₃ as having an incomplete octet of electrons. The distractors NF₃ and BrF were chosen in equal numbers, and the distractor SF₂ was chosen by the least number of candidates.

What is the explanation for the high melting point of sodium chloride?

A.  The covalent bond between sodium and chlorine atoms is strong.

B.  Electrostatic attraction between sodium and chloride ions is strong.

C.  Intermolecular forces in sodium chloride are strong.

D.  Delocalized electrons cause strong bonding in sodium chloride.

B

Which formula is correct?

A.  ${\mathrm{NH}}_4{\mathrm{PO}}_4$

B.  ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{PO}}_4$

C.  ${\left({\mathrm{NH}}_4\right)}_3{\mathrm{PO}}_4$

D.  ${\left({\mathrm{NH}}_4\right)}_3{\left({\mathrm{PO}}_4\right)}_2$

C

64% of candidates picked the correct formula for ammonium phosphate with (NH₄)₂PO₄ being the incorrect answer chosen most frequently. NH₄PO₄ or (NH₄)₃(PO₄)₂ was rarely selected.

Which describes a resonance structure?

A.  Double bond can be drawn in alternative positions.

B.  Bonds vibrate by absorbing IR radiation.

C.  A double and a single bond in the molecule

D.  A Lewis structure

A

What is the type of bonding in a compound that has high boiling and melting points, poor electrical conductivity, and low solubility in water?

A.  Ionic

B.  Molecular covalent

C.  Metallic

D.  Giant covalent

D

58% of the candidates identified giant covalent bonding as the bonding in compounds with high melting and boiling points, poor electrical conductivity and low solubility in water. The most commonly selected distractor was ionic bonding. The question discriminated well between high-scoring and low-scoring candidates.

Which species does not have resonance structures?

A. C₆H₆

B. NH₄⁺

C. CO₃²⁻

D. O₃

B

Identifying resonance structure had one of the highest discriminatory indices. Only the higher achieving candidates had much success with this.

Which species has the same molecular geometry as SO₃²⁻?

A.   BF₃

B.   SO₃

C.   PF₃

D.   CO₃²⁻

C

Which species has the longest carbon to oxygen bond length?

A.     CO

B.     CH₃OH

C.     CH₃CO₂⁻

D.     H₂CO 

B

Which compound has the shortest C to N bond?

A.  HCN

B.  CH₃CH₂NH₂

C.  CH₃CHNH

D.  (CH₃)₂NH

A

Along which series is the bond angle increasing?

A.  NH₃  H₂O  CH₄

B.  CH₄  NH₃  H₂O

C.  H₂O  NH₃  CH₄

D.  H₂O  CH₄  NH₃

C

Which compound has the greatest volatility under the same conditions?

A.  SO₂

B.  SiO₂

C.  SnO₂

D.  SrO

A

For which species can resonance structures be drawn?

A.  HCOOH

B.  HCOO^–

C.  CH₃OH

D.  H₂CO₃

B

Which of the following series shows increasing hydrogen bonding with water?

A. Propane < propanal < propanol < propanoic acid

B. Propane < propanol < propanal < propanoic acid

C. Propanal < propane < propanoic acid < propanol

D. Propanoic acid < propanol < propanal < propane

A

What is the name of the compound with formula Ti₃(PO₄)₂?

A. Titanium phosphate

B. Titanium(II) phosphate

C. Titanium(III) phosphate

D. Titanium(IV) phosphate

B

71% of candidates were able to name Ti₃(PO₄)₂ correctly. The most commonly chosen distractor was titanium(III) phosphate.