Deck 27: P-Block Chemistry

Question 1

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

Answer 1

True

Question 2

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

Answer 2

formal

Question 3

Which of the following oxidation states are common for Group 17 elements? Please select all that apply.

A) +7
B) +1
C) -1
D) +4

Answer 3

A, B, C

Question 4

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.
-SO₂

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

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.
-SiO₂

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

Question 6

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

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

Question 7

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

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

Question 8

Which of the following statements apply to the p-block elements? Please select all that apply.

A) The oxidation state of the common anions is always equal to the number of valence electrons minus eight.
B) The ionic character decreases left to right across the period.
C) The acidic character increases left to right across the period.
D) The maximum oxidation state of the cation, increases left to right across the Periodic Table.

Question 9

The incidence of the oxidation state two less than the group number in the p-block elements _______ down the group.

Question 10

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

Question 11

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.

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 12

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

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.

Question 13

Unlike iron, aluminium is naturally resistant to corrosion as a thin layer of oxide forms on the surface

Question 14

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

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 15

BI₃ is a much stronger Lewis acid than BF₃.

Question 16

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
ΔH_sub = 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

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 17

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

Question 18

The most abundant oxides of carbon and silicon have totally different structures. Carbon dioxide is a triatomic gas and silicon dioxide forms a macromolecular solid. The difference in structure of the two compounds is due to the difference in  bond strength.

Question 19

Which of the following species does not act as a Lewis Acid?

A) SiF₄
B) SnI₄
C) CCl₄
D) SiCl₄

Question 20

Cyanogen, (CN)₂, is sometimes called a pseudohalogen. Why? Please select all that apply:

A) It exists as a dimer.
B) It forms similar compounds to the halogens, e.g. Cl^- and CN^- both give a white precipitate with silver nitrate.
C) The bond between the CN-CN groups can be broken by UV light.
D) It reacts with halogens readily.

Question 21

KClO₃ and S are used in the heads of safety matches. The reaction between them (which is extremely exothermic) is initiated by friction caused by striking the head of the match against a strip of white phosphorus.

Question 22

Match the equation with the type of reaction occurring.
-O₂^2- → O^2_ + ¹/₂O₂

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

Question 23

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

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

Question 24

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

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

Question 25

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

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

Question 26

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

Question 27

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

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 28

Sulfur hexafluoride is very unreactive because the sulfur centre is extremely sterically hindered.

Question 29

Match the number of double bonds with the chlorine containing compounds. (Note: It might help to draw the Lewis structures of each chlorine compound.)
-HClO₄

A) 3
B) 2
C) 1

Question 30

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

A) 3
B) 2
C) 1

Question 31

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

A) 3
B) 2
C) 1

Question 32

ClF₅ is an example of an interhalogen.

Question 33

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

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