Deck 8: The Main-Group Elements

Question 1

The electron affinities of elements are always positive.

Answer 1

False

Question 2

When metallic hydrides are heated, they

A) decompose explosively to yield metal oxides.
B) liberate oxygen and hydrogen.
C) liberate hydrogen.
D) produce hydrogen ions.
E) do not change because they are extremely stable.

Answer 2

C

Question 3

Which of the following exists mainly as cations in compounds?

A) P
B) Ga
C) As
D) Si
E) Sr

Answer 3

E

Question 4

Trends in electron affinity are similar to those for ionization energy.

Question 5

Aluminum oxide dissolves in aqueous base .What are the products of this reaction?

A) Al(OH₂)₆³⁺(aq) and H₂(g)
B) Al₂O₃(s) and H₂(g)
C) Al(OH₂)₆³⁺(aq) and O₂(g)
D) Al(OH)₄^-(aq) and H₂(g)
E) Al(OH)₄^-(aq) and O₂(g)

Question 6

Al₂O₃(s) dissolves in aqueous acid to produce

A) Al(OH₂)₆³⁺(aq).
B) Al(OH)₄^-(aq) and O₂(g).
C) Al(OH)₄^-(aq).
D) Al(OH₂)₆³⁺(aq) and H₂(g).
E) Al(OH)₄^-(aq) and H₂(g).

Question 7

Write an equation for the second ionization energy of magnesium.

Question 8

Which of the following pairs of elements both have acidic oxides?

A) Ca and As
B) Mg and Al
C) B and Li
D) In and Sn
E) P and Se

Question 9

The valence electrons of elements in the lower left of the periodic table experience the greatest effective nuclear charge.

Question 10

Which of the following is a basic oxide?

A) CaO(s)
B) CO₂(g)
C) SO₂(g)
D) CO(g)
E) SiO₂(s)

Question 11

Which of the following does not act as a Lewis acid?

A) Na₂O
B) NO
C) NO₂
D) SO₃
E) CO₂

Question 12

Which of the following has the smallest polarizability?

A) Ca²⁺
B) S^2-
C) Cl
D) S

Question 13

Which of the following does not form a saline hydride?

A) Lithium
B) Barium
C) Calcium
D) Magnesium
E) Beryllium

Question 14

Which of the following pairs of elements have similar polarizability?

A) Be and Al
B) Li and Na
C) B and Al
D) Be and Mg
E) Mg and B

Question 15

Circle the species that has the largest radius: Ca²⁺,S^2-,S,Cl.

Question 16

Which of the following has the largest atomic radius?

A) In
B) Ga
C) Ge
D) Al

Question 17

All of the oxides of the following elements are amphoteric except

A) P
B) Ga
C) As
D) Sb

Question 18

Write the formula of the hydride ion.

Question 19

Which of the following is an acidic oxide?

A) CaO(s)
B) MgO(s)
C) Bi₂O₃(s)
D) Na₂O(s)
E) SiO₂(s)

Question 20

Which of the following compounds is predicted to have bonds with the most covalent character?

A) MgF₂
B) LiF
C) CsI
D) MgI₂
E) BaBr₂

Question 21

The alkali metals all react with water .Which is the most reactive metal?

A) Li
B) Na
C) Cs
D) Rb
E) K

Question 22

Lithium and sodium burn in air to produce

A) Li₂O(s) and Na₂O(s).
B) LiO₂(s) and Na₂O(s).
C) Li₂O(s) and Na₂O₂(s).
D) LiO₂(s) and Na₂O₂(s).
E) Li₂O₂(s) and NaO₂(s).

Question 23

Both the hydride ion and sodium metal reduce water.

Question 24

What is the formula of baking soda?

A) Na₂CO₃.H₂O
B) NaHCO₃
C) NaHSO₄
D) Na₂SO₄
E) Na₂CO₃

Question 25

What is the voltage for the water-splitting reaction to produce hydrogen and oxygen from water? (Consult a table of standard potentials.)

Question 26

The anhydrous material with the common name "Epsom salts" has what chemical formula?

A) MgSO₄ B) Mg(OH)₂
C) CaSO₄
D) CaCl₂
E) MgCl₂

Question 27

What is the formula of quicklime?

A) CaO
B) MgSO₄
C) Ca(OH)₂
D) CaCO₃
E) CaSO₄

Question 28

What property of lithium makes the lithium-ion battery an excellent energy storage device?

A) Li⁺ has strong polarizing power.
B) Lithium-ion is a good reducing agent.
C) Lithium has a high density.
D) Lithium has the most negative standard potential of all the elements.
E) Li⁺ has a small radius.

Question 29

Which of the following can be extracted by hydrometallurgical reduction of their ions with hydrogen? Consult a table of standard potentials.

A) Ni
B) Fe
C) Ag
D) Zn
E) Pb

Question 30

Order the following ions according to their radii from largest to smallest:
H^- ,Cl^-, F^-.

Question 31

Hydrogen can be made from fossil fuels in a series of two catalyzed reactions.One of these reactions,The re-forming reaction,Is

A) Cu(s) + 2H⁺(aq) $\rightarrow$ Cu²⁺(aq) + H₂(g).
B) 2H₂O(l) $\rightarrow$ 2H₂(g) + O₂(g).
C) CH₃OH(l) $\rightarrow$ 2H₂(g) + CO(g).
D) CH₄(g) + H₂O(g) $\rightarrow$ CO(g) + 3H₂(g).
E) Zn(s) + 2HCl(aq) $\rightarrow$ ZnCl₂(aq) + H₂(g).

Question 32

What occurs when beryllium is added to aqueous sodium hydroxide?

A) Be(OH)₂(s) precipitates.
B) Beryllium dissolves to form [Be(OH)₄]^2-(aq).
C) Beryllium dissolves to form [Be(OH₂)₆]²⁺(aq).
D) O₂(g) is produced.
E) No reaction occurs because beryllium is not soluble in aqueous sodium hydroxide.

Question 33

How do the saline hydrides react in water?

A) They reduce water and produce O₂(g).
B) They all produce H₃O⁺(aq).
C) They oxidize water and produce O₂(g).
D) Saline hydrides are actually insoluble in water.
E) They reduce water and produce H₂(g).

Question 34

In the following reaction
2KNO₃(s)+ 4C(s) $\rightarrow$ K₂CO₃(s)+ 3CO(g)+ N₂(g)
The reducing agent is

A) CO(g).
B) KNO₃(s).
C) K₂CO₃(s).
D) C(s).
E) N₂(g).

Question 35

Quicklime, CaO(s),Reacts with C(s)To produce A plus carbon monoxide.When A is added to water,B and C are produced.Write the formulas of A,B,And C.

A) Ca(s), O₂(g), and Ca(OH)₂(aq)
B) CaO(s) does not react with C(s).
C) CaC₂(s), H₂(g), and Ca(OH)₂(aq)
D) Ca(s), H₂(g), and Ca(OH)₂(aq)
E) CaC₂(s), C₂H₂(g), and Ca(OH)₂(aq)

Question 36

The reaction of potassium superoxide with water vapor produces

A) K₂O(s).
B) H₂O₂(l).
C) KHCO₃(s).
D) O₂(g).
E) H₂(g).

Question 37

Which of the following metals, Ag,Zn,Cu,Ni,Au,Pt,Sn,Cannot be extracted by hydrometallurgical reduction of their ions with hydrogen?

A) Au, Pt
B) Ag, Au, Pt
C) Zn, Ni, Au
D) Zn, Ni, Sn
E) Ag, Cu, Au, Pt

Question 38

Which of the substances below can be used to extinguish a magnesium fire?

A) Sand
B) Carbon dioxide
C) Nitrogen
D) All of the substances listed react with burning magnesium.
E) Water

Question 39

All of the following react with water to form hydrogen and a hydroxide except

A) Mg.
B) Na.
C) Ca.
D) K.
E) Be.

Question 40

The equation for the hydrometallurgical extraction of silver is

A) Ag⁺(aq) + Cl^-(aq) $\rarr$ AgCl(s).
B) Ag⁺(aq) + 2S₂O₃^2-(aq) $\rarr$ Ag(S₂O₃)₂^3-(aq).
C) Ag⁺(aq) + 2CN^-(aq) $\rarr$ Ag(CN)₂^-(aq).
D) 2Ag(s) + 2H⁺(aq) $\rarr$ Ag⁺(aq) + H₂(g).
E) Ag⁺(aq) + H₂(g) $\rarr$ 2Ag(s) + 2H⁺(aq).

Question 41

The allotropes of carbon are graphite,diamond,and the fullerenes.These are all network solids.

Question 42

Diborane has

A) 2 bridging hydrogens and 4 terminal hydrogens.
B) 1 BF₃^- anion and 1 BF₃⁺ cation.
C) 4 bridging hydrogens and 2 terminal hydrogens.
D) 6 terminal hydrogens and 1 boron-boron bond.
E) 1 bridging hydrogen, 4 terminal hydrogens, and an ionic hydrogen.

Question 43

In the thermite reaction,iron (III)oxide is the reducing agent.

Question 44

Which of the following are all allotropes?

A) Graphite, diamond, and C₆₀
B) Silicon, carbon, and C₆₀
C) Boron carbide and carbon
D) Carbon monoxide and carbon dioxide
E) Silicon carbide, diamond, and C₆₀

Question 45

Boron nitride is produced from the reaction of

A) B(s) and HCN(g).
B) B(s) and NH₃(g).
C) B₂O₃(s) and NH₃(g).
D) B₂H₆(g) and N₂(g).
E) B(s) and N₂(g).

Question 46

The formula of boric acid written as a Brønsted acid is

A) HB(OH)₂
B) B(OH₂)₃³⁺
C) B(OH)₄^-
D) HB(OH)₃
E) B(OH)₃OH₂

Question 47

The formula of diborane is

A) BH₃.
B) B₂H₆.
C) B₂H₄.
D) B₂H₂.
E) B₂H.

Question 48

Which of the following concentrated acids can be safely transported in passivated lead containers?

A) HClO₄
B) H₂SO₄
C) HI
D) HCl
E) HNO₃

Question 49

The formula of boric acid written as a Lewis acid is

A) B(OH)₃
B) HB(OH)₃
C) HB(OH)₄
D)B(OH)₄^-
E) HB(OH)₂

Question 50

The role of magnesium in chlorophyll is

A) that of a hydrogenation catalyst.
B) to keep the ring rigid.
C) that of a reducing agent.
D) that of an oxidizing agent.
E) to react with water to produce hydrogen.

Question 51

Sodium borohydride is an oxidizing agent.

Question 52

Sodium borohydride is produced from the reaction of

A) B(OH)₃(aq) and BCl₃(l).
B) NaH(s) and B(s).
C) NaH(s) and B₂O₃(s).
D) NaH(s) and B(OH)₃(aq).
E) NaH(s) and BCl₃(l).

Question 53

Which of the following is not true?

A) In diamond, each carbon atom is sp³-hybridized and linked to its four neighbors, with all electrons in C-C $\sigma$ -bonds.
B) C₆₀ is molecular and thus soluble in solvents like benzene.
C) Graphite consists of planar sheets of sp²-hybridized carbon atoms and electrons can move from one carbon to another through a delocalized $\pi$ -network formed by the overlap of unhybridized p-orbitals.
D) Graphite is an electrically conducting solid.
E) Diamond is an excellent conductor of heat.

Question 54

The molecule Al₂Br₆ is formed from two AlBr₃ molecules .This reaction is

A) a precipitation reaction.
B) a reduction reaction.
C) an oxidation reaction.
D) redox dimerization reaction.
E) a Lewis acid-base complex formation reaction.

Question 55

When magnesium burns in air, the product(s)
Is (are)

A) MgO.
B) MgO and Mg₃N₂.
C) MgAr.
D) MgCO₃.
E) MgS and MgO.

Question 56

The equation that corresponds to the K_a for boric acid is

A) B₄O₅(OH)₄²sup>-(aq) + 5H₂O(l) b 4H₃BO₃(aq) + 2OHsup>-(aq).
B) H₃BO₃(aq) + H₂O(l) b HB(OH)₃⁺(aq) + OH^-(aq).
C) (OH)₃BOH₂(aq) + H₂O(l) b B(OH)₄^-(aq) + H₃O⁺(aq).
D) B(OH)₄^-(aq) + H⁺(aq) b B(OH)₃(aq) + H₂O(l).
E) B₄O₇^2-(aq) + H₂O(l) b B₄O₈H^3-(aq) + H⁺(aq).

Question 57

When aluminum sulfate is dissolved in water,is the resulting solution acidic or basic? Explain.

Question 58

The oxides of In and Tl

A) are amphoteric.
B) react with base.
C) react with water.
D) are unstable and cannot be isolated.
E) are basic.

Question 59

What reaction produces diborane?

A) BH₃(g) and B(s).
B) BF₃(g) and NaBH₄(s).
C) B(s) and H₂(g).
D) B(s) and NH₃(g).
E) BCl₃(g) and NaH(s).

Question 60

Aluminum metal is produced by

A) reduction of Al₂O₃ with carbon.
B) electrolysis of a molten mixture of alumina, Al₂O₃, and cryolite, Na₃AlF₆.
C) treatment of Al₂O₃ with sodium hydroxide.
D) the thermite reaction.
E) electrolysis of brine containing Al₂(SO₄)₃.

Question 61

Polarizability is a measure of the ease with which an electron cloud can be distorted and is greatest for electron-rich atoms like fluorine.

Question 62

Silane is produced in the following reactions.
a.SiCl₄ + LiAlH₄ $\rightarrow$ SiH₄ + LiAlCl₄
b.Mg₂Si + 4HCl $\rightarrow$ SiH₄ + 2MgCl₂
Classify each reaction as a redox or displacement reaction.

Question 63

Saline carbides contain the anion(s)

A) C₂^2- and C^4-.
B) CH₂^2-
C) HC₂^-
D) CO₃^2- and HCO₃^-.
E) CN^- and N^3-.

Question 64

Of the following compounds, which does not exist?

A) NCl₅
B) PCl₃
C) PCl₅
D) NCl₃

Question 65

The products of the reaction of Al₄C₃(s) with water are

A) Al₂O₃(s) and CH₄(g).
B) Al(OH)₃(s) and C₂H₂(g).
C) Al(OH)₃(s) and C₂H₄(g).
D) Al₂O₃(s) and C₂H₂(g).
E) Al(OH)₃(s) and CH₄(g).

Question 66

All of the following contain silicates in various forms except

A) asbestos.
B) mica.
C) talc.
D) molecular sieves.
E) alum.

Question 67

The compound BeI₂ is an ionic compound.

Question 68

Which of the following molecules requires the most energy to split into gaseous atoms?

A) CO
B) F₂
C) O₂
D) N₂
E) Cl₂

Question 69

Carbon dioxide is the formal anhydride of

A) H₂CO₃
B) HCOOH
C) H₂CO
D)CO₃^2-

Question 70

Which of the following is a covalent carbide?

A) W₂C
B) Fe₃C
C) SrC₂
D) CaC₂
E) SiC

Question 71

Which of the following does not involve CO acting as a reducing agent?

A) PbO(s) + CO(g) $\rarr$ Pb(s) + CO₂(g).
B) CO(g) + H₂O(g) $\rarr$ CO₂(g) + H₂(g).
C) 2CO(g) + O₂(g) $\rarr$ 2CO₂(g).
D) Ni(s) + 4CO(g) $\rarr$ Ni(CO)₄(g).
E) Fe₂O₃(s) + 3CO(g) $\rarr$ 2Fe(s) + 3CO₂(g).

Question 72

Lead is obtained from the oxide PbO by

A) reduction with aluminum.
B) treatment with concentrated sulfuric acid.
C) reduction with carbon.
D) reduction with CO(g).
E) heating to 1600 ^$\circ$ C.

Question 73

All of the following elements form hydrides except

A) K
B) Be
C) Ca
D) Rb

Question 74

The sublimation of "dry ice" is spontaneous at 25 ^$\omicron$ C and 1 atm .What are the signs of $\Delta$ H ^$\omicron$ and $\Delta$ S ^$\omicron$ ,Respectively?

A) 0, +
B) +, -
C) -, +
D) +, +
E) -,-

Question 75

Which of the following is a saline carbide?

A) SiC
B) CaC₂
C) Mo₂C
D) Fe₃C
E) W₂C

Question 76

Consider the following possible reactions:
1.B(OH)₃(aq)+ H₂O(l) $\rightarrow$
2.SiH₄(g)+ H₂O(l)(trace OH^-(aq)) $\rightarrow$
3.CCl₄(l)+ H₂O(l) $\rightarrow$
4.SiCl₄(l)+ H₂O(l) $\rightarrow$
Which of the reactions that occur are Lewis acid-base reactions?"

A) 3 and 4
B) 2
C) 1, 3, and 4
D) 1
E) 1 and 4

Question 77

All of the following are silicon-oxygen compounds except

A) asbestos.
B) quartz.
C) talc.
D) diamond.
E) mica.

Question 78

The mineral spondumene contains long, straight chain silicates involving the SiO₃^2- unit.What is the shape of SiO₃^2-?

A) T-shaped
B) Ttetrahedral
C) Trigonal planar
D) Trigonal pyramidal
E) See-saw

Question 79

Which of the following is an interstitial carbide?

A) SrC₂
B) Al₄C₃
C) CaC₂
D) K₂C₂
E) W₂C

Question 80

Which of the following statements is false?

A) Oxides of nonmetals are acidic.
B) Elements with intermediate ionization energies form amphoteric oxides.
C) Elements with low ionization energies commonly form ionic oxides.
D) Oxides of main-group metals are acidic.