Deck 22: The Chemistry of the Main Group Elements

Question 1

Which of the following reactions describes the formation of a molecular compound of hydrogen?

A) 2K(s) + H₂(g) → 2KH(s)
B) 2Na(s) + H₂(g) → 2NaH(s)
C) Sr(s) + H₂(g) → SrH₂(s)
D) Si(s) + 2H₂(g) → SiH(g)
E) 2Al(s) + 3H₂(g) → 2AlH₃(s)

Answer 1

Si(s) + 2H₂(g) → SiH(g)

Question 2

Which of the following is the general formula for an alkali metal hydride? (M = metal)

A) MH
B) M(OH)₂
C) MH₂
D) MH₃
E) MOH

Answer 2

MH

Question 3

Approximately 300 billion liters of hydrogen is produced annually. The majority of the hydrogen is used in the production of ____.

A) ammonia
B) hydrogen chloride
C) methane
D) sulfuric acid
E) water

Answer 3

ammonia

Question 4

Which list contains the three most abundant elements in the Earth's crust?

A) hydrogen, helium, and lithium
B) sodium, calcium, and iron
C) oxygen, nitrogen, and iron
D) carbon, nitrogen, and oxygen
E) oxygen, aluminum, and silicon

Question 5

Use your knowledge of group properties to predict the chemical formula for selenic acid.

A) HSeO₂
B) H₂SeO₃
C) H₂SeO₄
D) H₃SeO₃
E) H₃SeO₄

Question 6

Catalytic steam reformation of hydrocarbons (such as methane) produce a mixture of

A) CO₂ and H₂O.
B) C and H₂.
C) O₂ and H₂.
D) CH₄ and H₂O.
E) CO and H₂.

Question 7

Which of the following compounds is a common oxide for phosphorus?

A) PO
B) P₂O₃
C) PO₃
D) PO₅
E) P₄O₁₀

Question 8

Metal hydrides are used to remove traces of water from nonpolar solvents. Write a balanced chemical equation for the reaction of lithium hydride and water.

A) LiH₂(s) + 2 H₂O( $\ell$ ) ? Li(s) + 2 H₃O⁺(aq)
B) 2 LiH(s) + 2 H₂O( $\ell$ ) ? 2 LiOH(s) + H₂(g)
C) 2 LiH(s) + H₂O( $\ell$ ) ? Li₂O(s) + 2 H₂(g)
D) 2 LiH(s) + H₂O( $\ell$ ) ? Li₂O(s) + 4 H⁺(aq)
E) LiH(s) + H₂O( $\ell$ ) ? Li(s) + H₃O⁺(aq)

Question 9

What is the oxidation state of the common ion formed from Na?

A) 1+
B) 2+
C) 3−
D) 2−
E) 1−

Question 10

What is the oxidation state of each nitrogen in dinitrogen oxide?

A) 4
B) 1
C) 0
D) 3
E) -3

Question 11

Which of the following is the most abundant metal on earth?

A) calcium
B) iron
C) copper
D) aluminum
E) zinc

Question 12

Predict the formula of the product resulting from reaction of elemental forms of Mg and P.

A) MgP
B) MgP₂
C) Mg_2P
D) MgP₃
E) Mg_3P2

Question 13

Which two elements are most abundant in our solar system?

A) hydrogen and helium
B) hydrogen and oxygen
C) helium and iron
D) hydrogen and iron
E) carbon and oxygen

Question 14

Which of the following reactions does not represent a commercial method for the large-scale production of hydrogen gas?

A) CH₄(g) + H₂O(g) → CO(g) + 3 H₂(g)
B) C(s) + H₂O(g) → CO(g) + H₂(g)
C) 2 H₂O(l) → 2 H₂(g) + O₂(g)
D) CO(g) + H₂O(g) → CO₂(g) + H₂(g)
E) None of the above

Question 15

The products of the reaction of strontium hydride and water are

A) SrOH + H₂.
B) Sr₂O + H₂.
C) Sr(OH)₂ + H₂.
D) SrO + H₂.
E) SrOH + O₂.

Question 16

Which of the following chemical equations shows the production of synthesis gas?

A) 2 H₂O(g) → 2 H₂(g) + O₂(g)
B) 16 CH₄(g) + 7 O₂(g) → 2 C₈H₁₈(g) + 14 H₂O(g)
C) C(s) + 2 H₂(g) → CH₄(g)
D) CO(g) + H₂O(g) → CO₂(g) + H₂(g)
E) C(s) + H₂O(g) → H₂(g) + CO(g)

Question 17

Which of the following is the second most abundant (by mass) element in the earth's crust, oceans, and atmosphere?

A) hydrogen
B) oxygen
C) carbon
D) aluminum
E) silicon

Question 18

What is the highest oxidation state possible for elements from Group 5A?

A) 2+
B) 4+
C) 5+
D) 6+
E) 7+

Question 19

The oxidation state per each nitrogen, given in parentheses, is correct in all the following cases except

A) HN₃ (1).
B) N₂O₃ (-6).
C) HNO₃ (5).
D) NH₄⁺ (-3).
E) N₂O (1).

Question 20

What is the formula of the common oxide formed from Group 5A elements? (E = main group element)

A) EO
B) EO₂
C) EO₃
D) E₄O₁₀
E) E₂O₇

Question 21

Which group 1A metal is the strongest reducing agent?

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

Question 22

Which of the following statements is INCORRECT?

A) Diagnostic imaging of the human digestive tract often requires a patient to consume a slurry of BaSO₄(s), a compound that contains the toxic Ba²⁺ ion.
B) Hydroxyapatite is a calcium containing compound that is the main component of tooth enamel.
C) Beryllium is toxic. Exposure (by breathing) to beryllium can cause berylliosis.
D) Most magnesium is obtained from seawater, where it is present at a roughly 0.05 M concentration.
E) Calcium is the central element in chlorophyll.

Question 23

All of the following statements concerning sodium are correct EXCEPT

A) most sodium compounds are water soluble.
B) sodium is soft and easily cut with a knife.
C) sodium is usually found in nature as the reduced metal or as a sulfide salt.
D) sodium ions help regulate osmotic pressure in the human body.
E) sodium is commercially prepared by electrolysis of molten NaCl.

Question 24

What mass of MgO would be produced by heating a 300.-kg sample that is 53.0% Mg(OH)₂? Assume complete reaction and no other source of magnesium.

A) 111 kg
B) 237 kg
C) 2.73 kg
D) 434 kg
E) 207 kg

Question 25

The primary product from the reaction of potassium and oxygen is _____.

A) KO
B) K₂O
C) KO₄
D) KO₂
E) KO₃

Question 26

Which of the following methods is used for the commercial production of sodium metal?

A) Electrolysis of molten Na₂CO₃
B) Electrolysis of NaCl(aq)
C) Electrolysis of molten NaCl using a Downs Cell
D) Reaction of potassium metal vapor with molten NaCl
E) Reduction of NaOH with carbon

Question 27

Elemental sodium is commercially produced by electrolysis of ____. A valuable by-product, ____, is simultaneously produced during the electrolysis.

A) NaCl( $\ell$ ), Cl₂(g)
B) NaH(g), H₂(g)
C) NaCl(aq), NaOH(aq)
D) Na₂O₂( $\ell$ ), O₂(g)
E) Na₂S(s), S₈(s)

Question 28

Which of the following elements does not produce hydrogen gas when it reacts with water?

A) Na(s)
B) MgH₂(s)
C) Ca(s)
D) LiH(s)
E) CaO(s)

Question 29

Molten Al₂O₃ is reduced by electrolysis at low potentials and high currents. If 7.5 × 10³ amperes of current is passed through molten Al₂O₃ for 12.0 hours, what mass of Al is produced? Assume 100% current efficiency.

A) 5.0 × 10² g
B) 3.0 × 10⁴ g
C) 9.1 × 10⁴ g
D) 2.7 × 10⁵ g
E) 3.1 × 10⁶ g

Question 30

Oxides of the alkaline earth family form ____ upon reaction with water.

A) basic solutions
B) acidic solutions
C) alkaline earth hydrides
D) oxygen gas
E) hydrogen gas

Question 31

What mass of CO₂ would be produced by heating a 600.-kg sample of limestone that is 68.9% CaCO₃? Assume complete reaction and no other source of carbon dioxide.

A) 182 kg
B) 413 kg
C) 264 kg
D) 30.3 kg
E) 600 kg

Question 32

Write a balanced chemical equation for the electrolysis of brine (salt water).

A) 2 NaCl(aq) + 2 H₂O( $\ell$ ) ? 2 Na(s) + 2 HCl(aq) + O₂(g)
B) 2 NaCl( $\ell$ ) ? 2 Na( $\ell$ ) + Cl₂(g)
C) 2 NaCl(aq) + O₂(g) ? Na₂O₂(s) + Cl₂(g)
D) 4 NaCl(aq) + O₂(g) ? 4 Na(s) + 2 OCl₂(g)
E) 2 NaCl(aq) + 2 H₂O( $\ell$ ) ? Cl₂(g) + 2 NaOH(aq) + H₂(g)

Question 33

Which of the following balanced chemical equations represents the decomposition of limestone at high temperature?

A) Ca(OH)₂(s) → CaO(s) + H₂O(g)
B) 2 CaO(s) → 2 Ca(s) + O₂(g)
C) CaCO₃(s) → CaO(s) + CO₂(g)
D) Ca(OH)₂(s) → CaH₂(s) + O₂(g)
E) 2 CaCO₃(s) → 2 Ca(s) + O₂(g) + CO₂(g)

Question 34

The primary source material for the commercial production of magnesium is

A) ores rich in MgCO₃.
B) ores rich in MgCl₂.
C) seashells.
D) seawater.
E) limestone.

Question 35

Aluminum is resistant to corrosion because:

A) its surface is coated with unreactive AlN.
B) its surface is coated with unreactive Al₂O₃.
C) it is a noble metal.
D) it has the greatest density of all naturally occurring metals.
E) it has a high positive standard reduction potential.

Question 36

Which of the following calcium compounds is an important reactant in the commercial production of phosphoric acid?

A) Apatites
B) Fluorites
C) Limestone
D) Slaked lime
E) Gypsum

Question 37

Write a balanced chemical equation for the reaction of potassium and water.

A) K(s) + H₂O( $\ell$ ) ? KO(s) + H₂(g)
B) 2 K(s) + 2 H₂O( $\ell$ ) ? 2 KOH(aq) + H₂(g)
C) 2 K(s) + 2 H₂O( $\ell$ ) ? K₂O₂(s) + 2 H₂(g)
D) 2 K(s) + H₂O( $\ell$ ) ? K₂O(s) + H₂(g)
E) 4 K(s) + 2 H₂O( $\ell$ ) ? 4 KH(s) + O₂(g)

Question 38

Which one of the following elements would react with chlorine most rapidly?

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

Question 39

Which of the following is the general valence shell electron configuration of Group 3A elements?

A) [Noble Gas Core]ns¹
B) [Noble Gas Core]ns²np¹
C) [Noble Gas Core]ns²np³
D) [Noble Gas Core]ns²np²
E) [Noble Gas Core]ns²np⁴

Question 40

Write a balanced chemical equation for the reaction of lime and water to form slaked lime.

A) CaO(s) + 2 H₂O( $\ell$ ) ? CaCO₃(s) + 2 H₂(g)
B) CaO(s) + H₂O( $\ell$ ) ? Ca(OH)₂(s)
C) Ca₃(PO₄)₂(s) + 2 H₂O( $\ell$ ) ? 2 CaHPO₄(aq) + Ca(OH)₂(aq)
D) CaCO₃(s) + H₂O( $\ell$ ) ? Ca(s) + H₃O⁺(aq) + CO₂(g)
E) CaCO₃(s) + H₂O( $\ell$ ) ? CaO(s) + H₂CO₃(aq)

Question 41

The only acid that decomposes silicon dioxide is ____.

A) CF₃CO₂H
B) H₂SO₄
C) HBr
D) HF
E) HClO₄

Question 42

In what way is cryolite (Na₃AlF₆) used in the production of aluminum?

A) Cryolite is a catalyst, it increases the rate of aluminum reduction.
B) Cryolite-bauxite mixtures melt at lower temperatures than pure bauxite.
C) Cryolite makes aluminum more corrosion resistant.
D) Cryolite is reduced to aluminum at the cathode.
E) Cryolite is oxidized to F₂(g) at the anode.

Question 43

Quartz is a pure crystalline form of _____.

A) silica, SiO₂
B) sodium silicate, NaSiO₄
C) calcium orthosilicate, Ca₂SiO₄
D) silicon tetrachloride, SiCl₄
E) silicon carbide, SiC

Question 44

Phosphorus was first isolated in 1669 by Hennig Brandt, a German alchemist. Brandt was able to isolate approximately 30 grams of phosphorus from 60 gallons of ________.

A) sea water
B) Chilean saltpeter
C) urea
D) honey
E) urine

Question 45

Which of the following statements is INCORRECT?

A) Carbon is classified as a nonmetal.
B) Silicon is classified as a metalloid.
C) Germanium is classified as a metal.
D) Tin is classified as a metal.
E) Lead is classified as a metal.

Question 46

In the United States, most sulfur is obtained from

A) the reduction of cinnabar, HgS.
B) S₈ deposits along the Gulf of Mexico.
C) the reduction of iron pyrite, FeS₂.
D) the reduction of copper sulfide, CuS.
E) the oxidation of H₂S gas.

Question 47

The Ostwald process is an industrial method of producing ____ from the oxidation of ____.

A) nitric acid, ammonia
B) ammonia, nitric acid
C) ammonia, nitrogen
D) nitric acid, nitrogen
E) dinitrogen monoxide, nitrogen

Question 48

The building block of silicate minerals is the

A) linear SiO unit.
B) the bent SiO₂ unit.
C) trigonal-bipyramidal SiO₅ unit.
D) tetrahedral SiO₄ unit.
E) the linear SiO₂ unit.

Question 49

Who developed the process for obtaining aluminum from bauxite ore?

A) Antoine Lavoisier
B) Fritz Haber
C) Michael Faraday
D) Herman Frasch
E) Charles Hall

Question 50

Which of the following nitrogen oxides are free radicals: NO, N₂O, NO₂, and/or N₂O₃?

A) NO and N₂O
B) N₂O and NO₂
C) NO₂ and N₂O₃
D) NO and NO₂
E) N₂O and N₂O₃

Question 51

Dinitrogen monoxide (laughing gas) can be produced by the careful decomposition of ammonium nitrate at 250 °C. Choose the correct balanced equation for this reaction.

A) NH₄NO₃(s) → N₂O(g) + 2 H₂(g) + O₂(g)
B) NH₄NO₃(s) + 2 N₂(g) → 3 N₂O(g) + 2 H₂(g)
C) NH₄NO₃(s) → N₂O(g) + 2 H₂O(g)
D) 2 NH₄NO₃(s) → N₂O(g) + 2 HNO₂(g) + H₂O(g) + 2 H₂(g)
E) 3 NH₄NO₃(s) → N₂O(g) + 2 N₂(g) + 8 H₂O(g)

Question 52

Bauxite ore is the primary source material in the commercial production of ___.

A) B
B) Al
C) Na₃AlF₆
D) NaOH
E) B₂H₆

Question 53

What is the total number of valence electrons in N₂?

A) 16
B) 17
C) 34
D) 11
E) 22

Question 54

Nitric acid decomposes slowly in sunlight with nitrogen dioxide and oxygen as reduction and oxidation products, respectively. Write a balanced chemical equation for this reaction.

A) HNO₃(aq) → NO₂(g) + 1/2 O₂(g)
B) HNO₃(aq) → NO₂(g) + 1/2 O₂(g) + H⁺(aq)
C) 2 HNO₃(aq) → 2 NO₂(g) + O₂(g) + H₂(g)
D) 4 HNO₃(aq) → 2 NO₂(g) + + N₂(g) + 3 O₂(g) + 2 H₂O(g)
E) 4 HNO₃(aq) → 4 NO₂(g) + O₂(g) + 2 H₂O(g)

Question 55

Which of the following statements is INCORRECT?

A) Quartz is a form of silicon dioxide that is used for controlling the frequency of radio and television transmissions.
B) Silica gel, a noncrystalline for of SiO₂, is used to keep electronics dry.
C) Passing beer through a bed of silica gel removes small particles that cause cloudiness.
D) Gaseous SiO₂ is a linear molecule with silicon-oxygen double bonds and a boiling point slight below 0 °C.
E) Silicon dioxide is resistant to attack from all acids except HF.

Question 56

What is the oxidation state of nitrogen in nitrogen dioxide?

A) 5
B) 4
C) 0
D) 1
E) -3

Question 57

The active ingredients in "strike anywhere" matches are _____ and the powerful oxidizing agent, KClO₃(s).

A) N₂H₄
B) P₄O₁₀
C) Mg₃N₂
D) P₄S₃
E) (HPO₃)₃

Question 58

Which of the following statements is INCORRECT?

A) Phosphoric acid gives a tart taste to carbonated beverages such as colas.
B) Sodium phosphate, Na₃PO₄, is a relatively strong base used in paint strippers.
C) Ca(H₂PO₄)₂⋅H₂O is used as an acid leavening agent in baking powder.
D) Ca₃(PO₄)₂ is a dark green compound used in latex paints.
E) Calcium monohydrogen phosphate is an abrasive and polishing agent in toothpaste.

Question 59

Which of the following statements concerning boron compounds is incorrect?

A) More than 20 neutral boron hydrides (general formula B_xH_y) are known.
B) The two boron atoms in B₂H₆ are connected by three-center, two-electron B-H-B bridges.
C) Borax, Na₂B₄O₇⋅10 H₂O, is used as a low-melting flux in metallurgy.
D) Sodium borohydride, NaBH₄, is a reducing agent used in organic chemistry.
E) Diborane, B₂H₆, is used as an oxidizing agent in organic chemistry.

Question 60

Hydrazine, N₂H₄, is produced by the Raschig process−the oxidation of ammonia with alkaline ____.

A) HNO₃(aq)
B) NaOCl(aq)
C) N₂(g)
D) HPO₄^2-(aq)
E) N₂O(g)

Question 61

Which of the following does not contain sulfur?

A) Acid rain
B) Egg protein
C) Amines
D) Volcanic gases
E) Barite

Question 62

Give two examples of the allotropes of elemental oxygen.

Question 63

One commercial method of producing Cl₂ is by electrolysis of aqueous NaCl.
NaCl(aq) + 2 H₂O( ) → Cl₂(g) + 2 NaOH(aq) + H₂(g)
Owing to environmental concerns, some manufacturers are shifting to the soda-lime method for NaOH production. Explain why this method is environmentally preferred. Write a balanced chemical equation for the production of NaOH from soda ash and lime.

Question 64

Pure oxygen can be produced by the catalyzed decomposition of potassium chlorate. Choose the correct balanced chemical equation for this reaction.

A) KClO₃(s) → KClO(s) + O₂(g)
B) 2 KClO₃(s) → 2 K(s) + Cl₂(g) + 3 O₂(g)
C) 2 KClO₃(s) → 2 KCl(s) + 3 O₂(g)
D) 2 KClO₃(s) → 2 KClO₂(s) + O₂(g)
E) KClO₃(s) → K(s) + ClO(g) + O₂(g)

Question 65

A class of aluminosilicate, called a(n) ________, contains regularly spaced holes and cavities. This type of aluminosilicate is often used as a catalyst.

Question 66

What is the molecular formula of chlorous acid?

A) HClO
B) HClO₂
C) HClO₃
D) HClO₄
E) HCl

Question 67

The primary product of the reaction of potassium and oxygen is ________. This compound is used in oxygen generators.

Question 68

Ammonium perchlorate can decompose violently according to the chemical equation below. 2 NH₄ClO₄(s) → N₂(g) + Cl₂(g) + 2 O₂(g) + 4 H₂O(g)
What volume of chlorine gas is produced by the decomposition of 120 g NH₄ClO₄ at 650 K and 1.0 atm? (R = 0.08206 L⋅atm/K⋅mol)

A) 27 L
B) 54 L
C) 91 L
D) 110 L
E) 3200 L

Question 69

What is the outer shell ground state electron configuration of At?

A) 6s²6p⁴
B) 7s²7p⁵
C) 7s²7p⁶
D) 6s²6p⁵
E) 6s²6p⁶

Question 70

Which of the following is the general formula for oxoanions formed by boron?

A) BO33−
B) BO32−
C) BO3−
D) BO42−
E) BO4−

Question 71

Silicon is purified in a process called ________, where a narrow segment of a silicon rod is melted and allowed to slowly recrystallize.

Question 72

Which of the following occurs uncombined in nature?

A) Cl
B) P
C) Ar
D) F
E) Br

Question 73

Which of the following elements is least likely to form a stable oxide?

A) Fe
B) Ca
C) S₈
D) P₄
E) He

Question 74

A(n) ________ reaction is one where an element or compound is simultaneously oxidized and reduced.

Question 75

Write a balanced chemical equation for the roasting of CuS.

A) CuS(s) + 2 HCl(aq) → CuCl₂(aq) + H₂(g) + S(s)
B) CuS(s) + O₂(g) → CuO₂(s) + S(s)
C) CuS(s) + O₂(g) → CuO(s) + SO(g)
D) CuS(s) + 2 HCl(aq) → CuCl₂(aq) + H₂S(g)
E) 2 CuS(s) + 2 O₂(g) → 2 CuO(s) + SO₂(g)

Question 76

Based on the following data, what is the I-I bond energy?
$\frac { 1 } { 2 }$ H₂(g) + $\frac { 1 } { 2 }$ I₂(g) ? HI(g); ?_rH° = 26.36 kJ/mol-rxn Bond
Bond Energy (kJ/mol)
H-H  435
H-I   295

A) 365 kJ/mol
B) 208 kJ/mol
C) -208 kJ/mol
D) -155 kJ/mol
E) 155 kJ/mol

Question 77

The most reactive nonmetallic element is _____. This element has been shown to form compounds with every other element except He and Ne.

A) oxygen
B) fluorine
C) chlorine
D) phosphorus
E) carbon

Question 78

Concentrated nitric acid reacts with copper to form NO₂(g). Dilute nitric acid reacts with copper to form NO(g). Why does the reaction involving the dilute acid give a different nitrogen oxide than the concentrated acid?

Question 79

Anhydrous hydrogen fluoride is used in all of the following applications EXCEPT

A) etching fluorescent light bulbs.
B) the production of refrigerants.
C) the reduction of alkali and alkaline earth metals.
D) the production of plastics.
E) the production of herbicides.

Question 80

Arrange the following in order of increasing ease of oxidation: At−, Cl−, I−, Br−

A) At− < Cl− < Br− < I−
B) Cl− < I− < At− < Br−
C) At− < Br− < I− < Cl−
D) Cl− < Br− < I− < At−
E) Br− < Cl− < I− < At−