Question 1

Gallium lies in Group 13 of the Period Table but a compound with empirical formula 'GaCl2' exists - how is this possible?

Accepted Answer

A)  Group 13 elements form +3 compounds and +2 compounds. 
B)  The compound is exhibiting the inert pair effect forming Ga+ and Cl2- ions. 
C)  The compound is exhibiting the inert pair effect and contains both Ga(I) and Ga(III) ions i.e. Ga+[GaCl4]-. 
D)  It forms a structure similar to aluminium chloride and is made up of three centre, four electron bonds. 
A)  Group 13 elements form +3 compounds and +2 compounds. 
B)  The compound is exhibiting the inert pair effect forming Ga+ and Cl2- ions. 
C)  The compound is exhibiting the inert pair effect and contains both Ga(I) and Ga(III) ions i.e. Ga+[GaCl4]-. 
D)  It forms a structure similar to aluminium chloride and is made up of three centre, four electron bonds. C

Question 2

Bond enthalpies get smaller for M-X as a group in the p block is descended.

Accepted Answer

A) True 
 B)False  True

Question 3

The bridging chlorine atoms in the dimer Al2Cl6 are involved in 3-centre 4-electron bonds.

Accepted Answer

A) True 
 B)False  True

Question 4

The elements of Group 16 are a mixture of metals, non metals and metalloids.

Accepted Answer

A) True 
 B)False

Question 5

Match the p-block oxide with the expected structure bearing in mind that covalent compounds are formed from elements of similar electronegativity by electron sharing.
-XeO4

Accepted Answer

A)  Covalent molecules 
B)  Covalent network with polar bonds 
C)  Covalent network 
D)  Ionic structure showing some covalency 
A)  Covalent molecules 
B)  Covalent network with polar bonds 
C)  Covalent network 
D)  Ionic structure showing some covalency

Question 6

Which elements of Group 18 form compounds that exist under standard conditions? Please select all that apply:

Accepted Answer

A)  He 
B)  Kr 
C)  Ne 
D)  Xe 
A)  He 
B)  Kr 
C)  Ne 
D)  Xe

Question 7

An enthalpy cycle for the formation of monovalent aluminium halides is given below.
 
Use the data given below (kJ mol-1) to show which oxidation state is favoured in each case.
I1 = 577 kJ mol-1 I2 = 1816 kJ mol-1 I3 = 2743 kJ mol-1
ΔHsub = 324 kJ mol-1
ΔH (AlF) = -910 kJ mol-1
ΔH (AlI) = -696 kJ mol-1
ΔH (AlF3) = -6380 kJ mol-1
ΔH (AlI3)= -4706 kJ mol-1

Accepted Answer

A)  aluminium(III) fluoride and aluminium(III) iodide 
B)  aluminium(I) fluoride and aluminium(III) iodide 
C)  aluminium(I) fluoride and aluminium(I) iodide 
D)  aluminium(III) fluoride and aluminium(I) iodide 
A)  aluminium(III) fluoride and aluminium(III) iodide 
B)  aluminium(I) fluoride and aluminium(III) iodide 
C)  aluminium(I) fluoride and aluminium(I) iodide 
D)  aluminium(III) fluoride and aluminium(I) iodide

Question 8

In the third period (Na to Cl), the M-X bond when X has lone pairs, is always stronger than the M-X bond of the corresponding element in the row above. Please select all that apply.

Accepted Answer

A)  Due to a short bond length, the lone pair repulsion between M and X is stronger for the first row. 
B)  Due to a short bond length in the first row, the electron rich ligands with lone pairs are brought close together and repel each other. 
C)  The bigger difference in electronegativity between the two species results in polarization of the bonds and more ionic character for the second row. 
D)  The bigger difference in electronegativity between the two species results in polarisation of the bonds and less ionic character for the second row. 
A)  Due to a short bond length, the lone pair repulsion between M and X is stronger for the first row. 
B)  Due to a short bond length in the first row, the electron rich ligands with lone pairs are brought close together and repel each other. 
C)  The bigger difference in electronegativity between the two species results in polarization of the bonds and more ionic character for the second row. 
D)  The bigger difference in electronegativity between the two species results in polarisation of the bonds and less ionic character for the second row.

Question 9

Match the equation with the type of reaction occurring.
-NH4NO3 (s) → N2O (g) + 2H2O (g)

Accepted Answer

A)  disproportionation 
B)  catenation 
C)  conproportionation 
D)  deliquescence 
A)  disproportionation 
B)  catenation 
C)  conproportionation 
D)  deliquescence

Question 10

Match the number of double bonds with the chlorine containing compounds. (Note: It might help to draw the Lewis structures of each chlorine compound.)
-HClO2

Accepted Answer

A)  3 
B)  2 
C)  1 
A)  3 
B)  2 
C)  1

Question 11

Match the p-block oxide with the expected structure bearing in mind that covalent compounds are formed from elements of similar electronegativity by electron sharing.
-Ga2O3

Accepted Answer

A)  Covalent molecules 
B)  Covalent network with polar bonds 
C)  Covalent network 
D)  Ionic structure showing some covalency 
A)  Covalent molecules 
B)  Covalent network with polar bonds 
C)  Covalent network 
D)  Ionic structure showing some covalency

Question 12

Match the number of double bonds with the chlorine containing compounds. (Note: It might help to draw the Lewis structures of each chlorine compound.)
-ClO2

Accepted Answer

A)  3 
B)  2 
C)  1 
A)  3 
B)  2 
C)  1

Question 13

Chlorofluorocarbons are responsible for depleting stratospheric ozone. Fluorine radicals react with ozone to generate oxygen and regenerate the fluorine radicals.

Accepted Answer

A) True 
 B)False

Question 14

BI3 is a much stronger Lewis acid than BF3.

Accepted Answer

A) True 
 B)False

Question 15

Match the p-block oxide with the expected structure bearing in mind that covalent compounds are formed from elements of similar electronegativity by electron sharing.
-SiO2

Accepted Answer

A)  Covalent molecules 
B)  Covalent network with polar bonds 
C)  Covalent network 
D)  Ionic structure showing some covalency 
A)  Covalent molecules 
B)  Covalent network with polar bonds 
C)  Covalent network 
D)  Ionic structure showing some covalency

Question 16

Oxidation states in covalently bonded compounds are often referred to as ______ oxidation states.

Accepted Answer

The answer of Oxidation states in covalently bonded compounds are...

Question 17

Why is the C-F bond significantly stronger than either the C-C or the F-F bond? Please select all that apply.

Accepted Answer

A)  C-F is strengthened by electrostatic interactions. 
B)  C-C is very weak due to a number of lone pairs. 
C)  F-F is very weak due to a number of lone pairs and a very short bond. 
D)  Bonds between atoms that are different tend to be stronger than bonds between atoms that are the same 
A)  C-F is strengthened by electrostatic interactions. 
B)  C-C is very weak due to a number of lone pairs. 
C)  F-F is very weak due to a number of lone pairs and a very short bond. 
D)  Bonds between atoms that are different tend to be stronger than bonds between atoms that are the same

Question 18

Match the equation with the type of reaction occurring.
-I3- + I2 → I5-

Accepted Answer

A)  disproportionation 
B)  catenation 
C)  conproportionation 
D)  deliquescence 
A)  disproportionation 
B)  catenation 
C)  conproportionation 
D)  deliquescence

Question 19

The bond dissociation enthalpies of the Group 17 elements in reducing order of magnitude is?

Accepted Answer

A)  F-F > Cl-C l >Br-Br > I-I > As-As 
B)  Cl-Cl > Br-Br > F-F > I-I > As-As 
C)  Cl-Cl > F-F > Br-Br > I-I > As-As 
D)  As-As > I-I > Br-Br > Cl-Cl > F-F 
A)  F-F > Cl-C l >Br-Br > I-I > As-As 
B)  Cl-Cl > Br-Br > F-F > I-I > As-As 
C)  Cl-Cl > F-F > Br-Br > I-I > As-As 
D)  As-As > I-I > Br-Br > Cl-Cl > F-F

Question 20

Match the equation with the type of reaction occurring.
-Cu(NO3)2·5H2O (s) → Cu(NO3)2 (aq)

Accepted Answer

A)  disproportionation 
B)  catenation 
C)  conproportionation 
D)  deliquescence 
A)  disproportionation 
B)  catenation 
C)  conproportionation 
D)  deliquescence

Exam 27: P-Block Chemistry

Gallium lies in Group 13 of the Period Table but a compound with empirical formula 'GaCl2' exists - how is this possible?

Bond enthalpies get smaller for M-X as a group in the p block is descended.

The bridging chlorine atoms in the dimer Al2Cl6 are involved in 3-centre 4-electron bonds.

The elements of Group 16 are a mixture of metals, non metals and metalloids.

Match the p-block oxide with the expected structure bearing in mind that covalent compounds are formed from elements of similar electronegativity by electron sharing. -XeO4

Which elements of Group 18 form compounds that exist under standard conditions? Please select all that apply:

In the third period (Na to Cl), the M-X bond when X has lone pairs, is always stronger than the M-X bond of the corresponding element in the row above. Please select all that apply.

Match the equation with the type of reaction occurring. -NH4NO3 (s) → N2O (g) + 2H2O (g)

Match the number of double bonds with the chlorine containing compounds. (Note: It might help to draw the Lewis structures of each chlorine compound.) -HClO2

Match the p-block oxide with the expected structure bearing in mind that covalent compounds are formed from elements of similar electronegativity by electron sharing. -Ga2O3

Match the number of double bonds with the chlorine containing compounds. (Note: It might help to draw the Lewis structures of each chlorine compound.) -ClO2

Chlorofluorocarbons are responsible for depleting stratospheric ozone. Fluorine radicals react with ozone to generate oxygen and regenerate the fluorine radicals.

BI3 is a much stronger Lewis acid than BF3.

Match the p-block oxide with the expected structure bearing in mind that covalent compounds are formed from elements of similar electronegativity by electron sharing. -SiO2

Oxidation states in covalently bonded compounds are often referred to as ______ oxidation states.

Why is the C-F bond significantly stronger than either the C-C or the F-F bond? Please select all that apply.

Match the equation with the type of reaction occurring. -I3- + I2 → I5-

The bond dissociation enthalpies of the Group 17 elements in reducing order of magnitude is?

Match the equation with the type of reaction occurring. -Cu(NO3)2·5H2O (s) → Cu(NO3)2 (aq)

Fundamentals

The Language of Organic Chemistry

Atomic Structure and Properties

Diatomic Molecules

Polyatomic Molecules

Solids

Acids and Bases

Gases

Reaction Kinetics

Molecular Spectroscopy

Analytical Chemistry

Molecular Characterisation

Energy and Thermochemistry

Entropy and Gibbs Energy

Electrochemistry

Phase Equilibrium and Solutions

Isomerism and Stereochemistry

Organic Reaction Mechanisms

Halogenoalkanes: Substitution and Elimination Reactions

Alkenes and Alkynes: Electrophilic Addition and Pericyclic Reactions

Benzene and Other Aromatic Compounds: Electrophilic Substitution Reactions

Aldehydes and Ketones: Nucleophilic Addition and Α-Substitution Reactions

Carboxylic Acids and Derivatives: Nucleophilic Acyl Substitution and Α-Substitution Reactions

Hydrogen

S-Block Chemistry

D-Block Chemistry

Filters

Gallium lies in Group 13 of the Period Table but a compound with empirical formula 'GaCl₂' exists - how is this possible?

The bridging chlorine atoms in the dimer Al₂Cl₆ are involved in 3-centre 4-electron bonds.

Match the p-block oxide with the expected structure bearing in mind that covalent compounds are formed from elements of similar electronegativity by electron sharing. -XeO₄

Match the equation with the type of reaction occurring. -NH₄NO₃ (s) → N₂O (g) + 2H₂O (g)

Match the number of double bonds with the chlorine containing compounds. (Note: It might help to draw the Lewis structures of each chlorine compound.) -HClO₂

Match the p-block oxide with the expected structure bearing in mind that covalent compounds are formed from elements of similar electronegativity by electron sharing. -Ga₂O₃

Match the number of double bonds with the chlorine containing compounds. (Note: It might help to draw the Lewis structures of each chlorine compound.) -ClO₂

BI₃ is a much stronger Lewis acid than BF₃.

Match the p-block oxide with the expected structure bearing in mind that covalent compounds are formed from elements of similar electronegativity by electron sharing. -SiO₂

Match the equation with the type of reaction occurring. -I₃^- + I₂ → I₅^-

Match the equation with the type of reaction occurring. -Cu(NO₃)₂·5H₂O (s) → Cu(NO₃)₂ (aq)