How many oxygen atoms are bonded to each silicon atom in
Of the atoms below, ________ is the most effective in forming π
Which one of the following is false concerning tritium?
A) It is radioactive, emitting alpha particles with a half-life of 12.3 yr.
B) It can be produced by neutron bombardment of lithium-6.
C) It has the same chemical properties as protium but reacts more slowly.
D) The atomic number of tritium is 1.
What method is used to produce the most hydrogen gas in the United
A) electrolysis of water
B) reaction of zinc with acid
C) reaction of methane with steam
D) reaction of coke (carbon) with steam
E) reaction of metallic sodium with water
Water gas is ________.
A) H2O and H2
B) CO2 and O2
C) H2O and CO2
D) H2O and CO
E) H2 and CO
What is the primary commercial use of hydrogen in the United
A) as a rocket fuel, especially on the space shuttle
B) hydrogenation of vegetable oils
C) manufacture of methanol
D) manufacture of ammonia by the Haber process
E) as an automobile fuel
Isotopes of hydrogen ________.
A) have the same atomic number and different mass numbers
B) have the same atomic number and the same mass number
C) have different atomic numbers and different mass numbers
D) have different atomic numbers and the same mass number
E) are exactly alike
Which of the following would produce a basic solution?
A) Na2O and CaO
B) CO and CO2
C) CaH2 only
D) Na2O, CaO, and CaH2
E) CO, CO2, and CaH2
Which of the following would produce an acidic solution?
A) Na2O and MgO
B) Na2O, MgO, and CaH2
D) CaH2 only
E) CO, CO2, and CaH2
How are the oxygen-containing compounds of xenon made?
A) by direct combination of the elements
B) by reaction of xenon with peroxide
C) by thermal decomposition of the xenon hydroxide
D) by reaction of the corresponding xenon fluoride with water
E) Xenon is inert and does not form compounds with oxygen.
Which of the following compounds is the most stable?
Consider the following xenon compounds:
(i) XeCl2 (ii) XeCl4 (iii) XeO4 (iv) XeOCl4 (v) XeO3
Which of the compounds is(are) polar?
A) (i) only
B) (iii) and (iv)
C) (iv) and (v)
D) (ii) and (iii)
E) (iv) only
The heavier noble gases are more reactive than the lighter ones
A) the lighter noble gases exist as diatomic molecules
B) the lighter noble gases have complete octets
C) the heavier noble gases are more abundant
D) the heavier noble gases have low ionization energies relative to the lighter ones
E) the heavier noble gases have greater electron affinities
Which noble gas is known to form a variety of binary
Interhalogen compounds ________.
A) are exceedingly reactive
B) contain halogens in both positive and negative oxidation states
C) are powerful oxidizing agents
D) all of the above
Which elemental halogen(s) can be used to prepare from NaI?
A) F2 only
B) Cl2 only
C) Br2 only
D) both Cl2 and Br2, but not F2
E) F2, Cl2, and Br2
Which halogen is the most easily oxidized?
Which equation correctly represents the reaction between silica and
A) SiCl4 + 4HF → SiF4 + 4HCl
B) SiO2 + 6HF → H2SiF6 + 2H2O
C) SiCl2 + 2HF → SiF2 + 2HCl
D) SiH4 + 4HF → SiF4 + 4H2
E) none of the above
The interhalogen compound ICl3 can form but BrCl3 cannot form. This
is because ________.
A) iodine is large enough to accommodate three chlorine atoms around itself but bromine is not
B) bromine is not electronegative enough to react with chlorine
C) bromine is too electronegative to react with chlorine
D) iodine can have a positive oxidation state but bromine cannot
E) iodine can have a negative oxidation state but bromine cannot
Chlorine can have a positive oxidation state ________.
A) if it combines with bromine or iodine
B) if it combines with oxygen or fluorine
C) if it combines with hydrogen
D) if it combines with an alkali metal
E) in its elemental form
The oxidation state of fluorine in its compounds is ________.
A) positive unless it combines with another halogen
B) negative unless it combines with another halogen
C) negative unless it combines with oxygen
D) negative unless it combines with an active metal
E) always negative
The most stable allotrope of oxygen is ________.
Which of the following react with oxygen to form superoxides?
Nearly all commercial oxygen is obtained ________.
A) from air
B) by electrolysis of water
C) by thermal decomposition of potassium chlorate
D) by thermal cracking of petroleum
E) as a byproduct of the preparation of aluminum in the Hall process
Which of the following statements is false?
A) Ozone is a better reducing agent than O2 (g).
B) Ozone is produced by passing electricity through dry O2 (g).
C) Ozone oxidizes all of the common metals except gold and platinum.
D) Ozone decomposes to O2 and O.
E) Ozone is an allotrope of oxygen.
A disproportionation reaction is one in which ________.
A) a single element is both oxidized and reduced
B) a compound is separated into its constituent elements
C) the ratio of combination of two elements in a compound changes
D) aqueous ions combine to form an insoluble salt
E) an insoluble salt separates into ions
The oxidation state of oxygen in OF2 is ________.
________ are typically basic while ________ are typically
A) Nonmetal oxides, metal oxides
B) Metals, nonmetals
C) Metal oxides, nonmetal oxides
D) Nonmetals, metals
Amphoteric oxides are also known as ________.
A) basic oxides
B) basic anhydrides
C) acidic oxides
D) acidic anhydrides
E) none of the above
Which element in group 7A is not capable of having an expanded
Which element in group 6A is not capable of having an expanded
What sulfur compound is used to sterilize wine?
What is the major commercial source of elemental sulfur?
A) sulfide minerals
B) sulfate minerals
C) underground deposits of elemental sulfur
E) coal and petroleum
Which form of elemental sulfur is the most stable at room
A) rhombic sulfur
The prefix thio- denotes ________.
A) replacement of an oxygen atom by a sulfur atom
B) a sulfur—sulfur double bond
C) sulfur in a negative oxidation state
D) a sulfur—oxygen double bond
E) an allotropic form of sulfur
The oxidation numbers of sulfur in the sulfate ion, sulfite ion,
sulfur trioxide, and hydrogen sulfide are ________, ________,
________, and ________, respectively.
A) +4, -2, +4, +6
B) +6, +2, +4, +6
C) +6, +4, +6, -2
D) +4, +6, +4, -2
E) -2, +6, -2, 0
Which one of the following is sodium thiosulfate?
Which one of the following is true concerning pure hydrazine?
A) It is a weak reducing agent.
B) It can be made by reaction of nitrogen and ammonia.
C) It is used as a rocket fuel.
D) It is a hydride of oxygen.
E) It is a hydride of ammonia.
The Ostwald process is by which NH3 is converted commercially into
The oxidation number of N in NO3- is ________.
The oxidation number of N in NO2- is ________.
The oxidation number of Pb in PbO2 is ________.
Which of the following equations correctly represents the combustion
A) N2H4 (l) + O2 (g) → NH3 (g) + HNO2 (g)
B) N2H4 (l) + 2O2 (g) → 2NO2 (g) + 2H2 (g)
C) N2H4 (l) + O2 (g) → 2 NO (g)
D) N2H4 (l) + O2 (g) → N2 (g) + 2 H2O (g)
E) N2H4 (l) + O2 (g) → N2 (g) + 2H2 (g) + O2 (g)
The oxidation numbers of nitrogen in the nitride ion, hydrazine,
ammonium cation, and nitrate ion are ________, ________, ________, and
A) -3, -2, -3, +5
B) +3, -2, -3, +5
C) +3, -2, +1, +3
D) -3, +2, +1, +5
E) -3, +2, -3, +3
Which equation correctly represents what happens when N dissolves in
A) NO2 (g) + H2O (l) → 2H+ (aq) + NO3- (aq)
B) 3NO2 (g) + H2O (l) → 2H+ (aq) + 2NO3- (aq) + NO (g)
C) NO2 (g) + H2O (l) → H2O2 (aq) + NO (g)
D) 2NO2 (g) + H2O (l) → 2H+ (aq) + NO42- (aq) + NO (g)
E) 2NO2 (g) + 2H2O (l) → 2HNO2 (aq) + O2 (g) + H2 (g)
The reaction between nitrogen dioxide and water is a
Of the following substances, ________ is both a very strong acid and
a powerful oxidizing agent.
Which phosphorus chloride compound will form in the reaction of
phosphorus with excess chlorine gas?
What are the products of the reaction of PF3 (g) and water?
A) phosphorous acid and hydrofluoric acid
B) elemental phosphorus and hydrofluoric acid
C) phosphoric acid and fluorine gas
D) elemental phosphorus and fluorine gas
E) phosphoric acid and phosphorous acid
What are the products of the reaction of PCl5 (g) and water?
A) phosphoric acid and phosphorous acid
B) elemental phosphorus and hydrochloric acid
C) phosphoric acid and chlorine gas
D) elemental phosphorus and chlorine gas
E) phosphoric acid and hydrochloric acid
Which one of the following is false concerning
A) It is the most recently discovered crystalline allotrope of carbon.
B) It consists of individual molecules like C60 and C70.
C) It is a molecular form of carbon.
D) It is made up of Cl2 molecules.
E) It is made up of molecules that resemble soccer balls.
Of the following, which is most likely to form interstitial
A) active metals
B) transition metals
C) boron and silicon
D) alkaline earth metals
E) alkali metals
Which of the following would produce the most strongly acidic aqueous
How many lone pair of electrons are there in one molecule of carbon
Which of the following is not an allotropic form of carbon?
B) carbon dioxide
E) All of the above are allotropic forms of carbon.
Which of the following statements best describes graphite?
A) It is a soft, slippery, and black solid that has a metallic luster and conducts electricity.
B) It is a soft, slippery, and black gas that has a metallic luster and conducts electricity.
C) It is a soft, slippery, and black liquid that has a metallic luster and conducts electricity.
D) It is a soft, slippery, and black solid that has a metallic luster and does not conduct electricity.
E) It is a soft, slippery, and black solid that has a nonmetallic dull look and does not conduct electricity.
Carbon dioxide is produced ________.
A) in blast furnaces when metal oxides are reduced with CO
B) by combustion of carbon-containing substances in an excess of oxygen
C) when carbonates are heated
D) by fermentation of sugar during the production of ethanol
E) by all of the above processes
Which of the following would produce the strongest basic aqueous
Which equation correctly represents the reaction between carbon
dioxide and water?
A) CO2 (aq) + H2O (l) → H2CO3 (aq)
B) CO2 (aq) + H2O (l) → H2 (g) + CO (g) + O2 (g)
C) CO2 (aq) + H2O (l) → H2O2 (aq) + CO (g)
D) CO2 (aq) + 2H2O (l) → CH4 (g) + 2O2 (aq)
E) CO2 (aq) + H2O (l) → H2CO (aq) + O2 (g)
What is the function of the carbon fibers in a composite?
A) to provide a structure to help the epoxy resin solidify in the desired shape
B) to transmit loads evenly in all directions
C) to provide resistance to oxidation
D) to provide ultraviolet protection
E) to "spread out" the epoxy so that it remains more flexible
The arrangement of oxygen atoms around a silicon atom in
SiO44- is ________.
A) square planar
E) trigonal pyramidal
Addition of to soda-lime glass ________.
A) imparts a greater ability to withstand temperature change
B) imparts a deep blue color
C) results in a denser glass with a higher refractive index
D) results in a glass with a lower melting point
E) results in opaque glass
Replacement of CaO by PbO in soda-lime glass results in
A) denser glass with a higher refractive index
B) glass with a deep blue color
C) opaque glass
D) a softer glass with a lower melting point
E) a harder glass with a higher melting point
Soda-lime glass contains ________.
A) SiO2 and aluminum
B) SiO2, CaO, and Na2O
C) SiO2, CO2, and citric acid
D) SiO2, CO2, Na2O
E) pure SiO2
Additives can be used in soda-lime glass to alter its
A) ability to withstand temperature change
D) melting point
E) any of the above
Silicones are ________.
A) chains of alternating silicon and oxygen atoms with attached organic groups
B) three-dimensional covalent networks of SiO4 tetrahedra
C) three-dimensional covalent networks of silicon atoms
D) flat sheets of silicon atoms
E) flat sheets of silicon and hydrogen atoms
Silicones can be oils or rubber-like materials depending on
A) the silicon-to-oxygen ratio
B) the length of the chain and degree of cross-linking
C) the percentage of carbon in the chain
D) the percentage of sulfur in the chain
E) the oxidation state of silicon in the chain
Sodium borohydride, NaBH4 , is a strong reducing agent because
A) Na+ is easily reduced to Na (s)
B) boron easily changes its oxidation number from +3 to -3
C) boron is readily oxidized from -3 oxidation state to +3
D) hydrogen can be easily oxidized from -1 oxidation state to +1
E) hydrogen is easily reduced from +1 oxidation state to 0
The primary commercial use of nitric acid is ________.
A) in the manufacture of plastics
B) in the manufacture of explosives
C) in pool water maintenance
D) in the manufacture of fertilizers
E) in the manufacture of anti-depressant drugs
Which one of the following is true concerning borax?
A) It is the hydrated sodium salt of tetraboric acid.
B) It is found in dry lake deposits in California.
C) Its aqueous solutions are alkaline.
D) It is commonly used in cleaning products.
E) All of the above are true.
A borane is a ________.
A) compound containing only boron and oxygen
B) compound containing only boron and aluminum
C) compound containing only boron and hydrogen
D) compound containing only boron and carbon
E) three-dimensional covalent network of boron atoms
Which of the following equations correctly represents the reaction of
B2H6 with oxygen?
A) B2H6 (g) + 3O2 (g) → B2O3 (s) + 3H2O (g)
B) B2H6 (g) + O2 (g) → B2O2 (s) + 3H2 (g)
C) B2H6 (g) + 2O2 (g) → B2H2 (s) + 2H2O2 (aq)
D) B2H6 (g) + 2O2 (g) → B2O2 (s) + 3H2 + O2 (g)
E) B2H6 (g) + O2 (g) → H2B2O2 (s) + 2H2 (g)
________ can violate the octet rule in its compounds.
E) none of these elements can violate the octet rule.
B2O3 is the anhydride of ________.
A) borous acid
C) tetraboric acid
D) boric acid
Boric acid condenses to form tetraboric acid according to the
A) 4H3BO3 (s) → 2H2B2O7 (s) + 3H2O (g)
B) 2H3BO3 (s) → HB2O2 (s) + 4H2O (g)
C) 4H3BO3 (s) → HB4O8 (s) + 4H2O (g)
D) 2H3BO3 (s) → H2B4O7 (s) + 3H2O (g)
E) 4H3BO3 (s) → H2B4O7 (s) + 5H2O (g)
The most common isotope of hydrogen is sometimes referred to as
D) heavy hydrogen
E) common hydrogen
In metallic hydrides, the oxidation number of hydrogen is considered
to be ________.
Hydrogen can form hydride ions. Elements in group ________ typically
form ions with the same charge as the hydride ion.
Hydrogen can combine with ________ to form a metallic
A) an element from group 5A
B) an element from group 7A
C) an element from group 8A
D) an element from group 1A
E) an element from group 6A
Hydrogen can have oxidation states of ________.
A) +1 only
B) -1, 0, and +1
C) 0 and +1 only
D) -1 and +1 only
E) 0 only
________ has the highest boiling point of following series.
The electron-pair geometry and molecular geometry of XeF4 are
________ and ________, respectively.
A) octahedral; square pyramidal
B) tetrahedral; tetrahedral
C) octahedral; linear
D) octahedral; square planar
E) octahedral; bent
Hybridization of Xe in XeF4 is ________ and in XeF2 is
A) sp3d2, sp3d2
B) sp3d, sp3d2
C) sp3d2, sp3d
D) sp3, sp3d
E) sp3, sp3d2
The number of electrons in the valence shell of Xe in XeF6 is
What is the oxidation state of xenon in XeO2F2?
What is the oxidation state of xenon in XeO4?
Br2 can be prepared by combining NaBr with ________.
The active ingredient in many liquid bleaches is ________.
Which halogen can react with fluorine to form the compound
Which halogen forms an oxyacid with the formula HXO2?
The primary commercial use of oxygen is ________.
A) for the treatment of respiratory distress
B) in oxyacetylene welding
C) as a household bleach
D) as an oxidizing agent
E) to charge oxygen-containing cylinders used by deep-sea divers
Only the most active metals react with oxygen to form
Dissolving 2.0 mol of ________ in 1.0 L of water at 25 °C would yield
the most acidic solution.
The nitride ion is a strong Br∅nsted-Lowry base. Mg3N2 reacts with
water to produce ________.
The primary commercial use of elemental nitrogen is in the
manufacture of ________.
C) nitrogen-containing fertilizers
E) chlorine bleach
What is the coefficient of NO2 when the following disproportionation reaction is balanced?
NO2 (g) + H2O (l) →H+ (aq) + NO3- (aq) + NO (g)
The Haber process is used to make ________ from ________.
A) HNO3, N2
B) O2, KClO3
C) NH3, N2
D) NO2, O2
E) NO, N2
Most mined phosphate rock is ________.
A) used as a strong acid
B) used as a reducing agent
C) used as a detergent
D) converted to fertilizer
E) discarded as a by-product
The white allotropic form of ________ bursts into flame when exposed
The two allotropic forms of phosphorus are ________ and
A) black, red
B) white, black
C) white, yellow
D) white, red
E) black, yellow
The principal combustion products of compounds containing carbon and
hydrogen in the presence of excess O2 are ________.
A) CO2 and H2O
B) CO2 and H2O2
C) CO2 and H
D) C(graphite) and H2
E) CO2 and H2
________ is formed when wood is heated strongly in the absence of
B) Carbon black
C) Sulfur dioxide
To produce carbon black, ________.
A) diamond is exposed to extremely high pressures and temperatures
B) wood is strongly heated in the absence of oxygen
C) coal is strongly heated in the absence of oxygen
D) hydrocarbons such as methane are heated in a very limited supply of oxygen
E) graphite is cooled to -273 °C
Although CaCO3 is essentially insoluble in pure water, it dissolves
slowly in acidic ground water due to formation of ________.
A) insoluble Ca(OH)2
B) soluble Ca(OH)2
C) insoluble Ca(HCO3)2
D) soluble Ca(HCO3)2
E) soluble CaO
The compound whose formula is CaC2 is ________.
A) calcium carbide
C) carbon calcide
D) calcium dicarbon
An example of a form of pure carbon that contains only sp3 hybridized
carbon atoms is ________.
D) carbon black
What is the oxidation state of carbon in the carbonate ion?
The correct name of H2CO3 is ________.
A) hydrogen carbide
B) hydrogen carbonate ion
C) carbonate ion
D) carbonic acid
E) carboxylic acid
The most common oxidation state of silicon is ________.
Pyrex® glass is formed by adding an oxide of ________ to soda-lime
SiO44- is the ________ ion.
A) orthosilicate ion
B) silicide ion
C) thiosilicate ion
D) silicon tetroxide ion
E) siliconate ion
The oxidation state of silicon in SiO44- is
The disilicate ion is ________.
Glass is ________ whereas quartz is ________.
A) hard, soft
B) crystalline, amorphous
C) amorphous, crystalline
D) pure Si , a mixture of Si and carbonates
E) breakable, not breakable
What is the formula of borax?
E) Na2B4O7 ∙ 10H2O
Which group 3A element is a metalloid?
Tetraboric acid, H2B4O7, is prepared by heating boric acid, H3BO3 (a
condensation reaction involving water loss). If 400.0 mmol H3BO3 are
used, what mass (g) of H2O is formed, assuming quantitative
Diborane is ________.
Boric oxide is ________.
The correct name for NaBH4 is ________.
A) sodium borohydride
B) sodium borate
C) sodium boride
D) sodium borite
E) sodium hydroboride
The most nonmetallic element is ________.
The least electronegative of the elements below is ________.
In the following chemical equation
PCl3 + 3H2O →
the products (when the equation is balanced) are ________.
A) H3PO3 + 3HCl
B) P(OH)3 + 3HCl
C) H(ClO)3 + PH3
D) HPCl2 + Cl(OH)3
E) PO3 + 3HCl
Which of the following is a molecular hydride?
Which of the following is an ionic hydride?
Which of the following compounds would produce the most acidic
The oxidation state of sulfur in the SO3 molecule is
The oxidation state of phosphorous in the PF5 molecule is
The oxidation state of chlorine in the ClO- molecule is
Which one of the following compounds is superoxide?
Which compound would produce a basic aqueous solution?
What is the F—Xe—F bond angle in XeF2?
The oxidation number of xenon in XeF4 is ________.
Which equation correctly represents the reaction between elemental
chlorine and sodium iodide?
A) Cl + NaI → I + NaCl
B) Cl- + NaI → I- + NaCl
C) Cl2 + 2NaI → I2 + 2NaCl
D) Cl + NaI → 1/2 I2 + NaCl
E) Cl2 + NaI → NaCl2 + I-
Which one of the following compounds is peroxide?
D) both Li2O2 and LiO2
The oxidation state of oxygen in O2F2 is ________.
What is the molecular shape of the SF2 molecule?
D) trigonal planar
E) trigonal pyramidal
The oxidation state of nitrogen in the NO2 molecule is
The oxidation state of As in the As2O3 molecule is ________.
The oxidation number of B in B2O3 is ________.
Which of the following is the nitride ion?
Which pair of formula/name is incorrect?
A) NO2 / dinitrogen oxide
B) N2O / nitrous oxide
C) NO / nitric oxide
D) N2O4 / dinitrogen tetroxide
E) N2O5 / dinitrogen pentoxide
The molecular shape of the PF3 molecule is ________.
A) trigonal pyramidal
B) trigonal bipyramidal
How many lone pair of electrons are there in one molecule of
What are the five crystalline allotropes of carbon?
graphene, carbon nanotubes, diamond, graphite, and buckminsterfullerene
Of Li, K, P and Ne which is the most electronegative?
P is the most electronegative
In a proton transfer reaction the weaker a Br∅nsted-Lowry acid the ________ is its conjugate.
D2O, deuterium oxide, is also known as ________.
H2 is reacted with ________ to produce methanol.
CO; carbon monoxide
What noble gas is radioactive?
Of the nonradioactive halogens, which is the largest?
Which group 7A halogen is radioactive?
In a hypohalous acid, the oxidation state of the halogen is ________.
Write the correctly balanced equation for the reaction between elemental fluorine and sodium iodide.
F2 + 2 NaI → I2 + 2 NaF
Write the correctly balanced equation for the reaction between elemental iodine and sodium bromide.
I2 + NaBr → no reaction
The acid and salts of which halogen-oxyanion are the most stable?
What anion containing Cl is used as a rocket fuel?
Group 8A elements are all gases at room temperature except for ________.
What is the oxidation state of oxygen in the superoxide ion?
In oxygen compounds, a disproportionation reaction is a reaction in which oxygen is simultaneously ________.
oxidized and reduced
What process replenishes O2?
Hydrogen peroxide is a highly polar and strongly hydrogen-bonded liquid. It decomposes to form water and ________.
If a metal forms more than one oxide, the acidic character of the oxide increases as the oxidation state of the metal ________.
What sulfur gas is used to sterilize wine?
The electrical conductivity of ________ is low in the dark, but increases on exposure to light.
The danger from mixing ammonia with bleach is the production of ________.
KNO3 and NaNO3 are also known as ________.
What is the primary commercial source of elemental nitrogen?
fractional distillation of liquid air
What group 5A element is the least metallic?
Low levels of arsenic consumption can lead to ________ or bladder cancer.
Why does calcium carbonate dissolve in water containing carbon dioxide?
because the dissolved carbon dioxide makes the water slightly acidic
The balanced equation for the production of ethylene from calcium carbide is ________.
CaC2 + 2H2O → Ca(OH)2 + C2H2
What is an acetylide?
a carbide containing the C22- ion
What is meant by the term "composite"?
a combination of two or more materials
What are the principal components used in making soda-lime glass?
calcium oxide, sodium oxide, and silicon dioxide
What effect does substitution of K2O for Na2O in making soda-lime glass have in its properties?
increases hardness and melting point
Chains of silicate tetrahedra are called ________.
Compounds containing only boron and hydrogen are called ________.
Air containing 4% H2 can be explosive.
The reduction of O2 by sodium hydride produces lye.
Xenon can have oxidation states of 2, 4, 6, and 8.
The instability of xenon fluorides is due to its negative enthalpy of formation.
Ozone is a pale blue poisonous gas with an irritating odor.
All oxides are ionic compounds.
Oxides can react with water to form acids or bases.
The reduction of metal oxides uses carbon monoxide.
Calcium carbide is a solid source of acetylene.
Explain why silicon does not form any allotropes with structures analogous to that of graphite or buckminsterfullerenes, even though it is in the same group as carbon.
Silicon is large enough to prevent efficient sideways-overlap of p orbitals required for π-bond formation.
Explain why hydrofluoric acid etches glass.
Hydrofluoric acid forms a soluble hexafluorosilic acid (H2SiF6), removing silicon from glass and, consequently, destroying it.
An aqueous solution of HF is considered a relatively ________ acid.
What are the three steps in the Ostwald process of nitric acid synthesis?
1) oxidation of ammonia to NO and water, 2) oxidation of NO to NO2, 3) reaction of NO2 with water.
Photochemical decomposition of HNO3 produces small amounts of NO2 which causes the solution to sometimes become ________ in color.
Describe the major difference in the charge distribution in CH4 and SiH4.
Even though both C—H and Si—H bonds are polar, both CH4 and SiH4 are nonpolar due to their tetrahedral symmetry. Because carbon is more electronegative than hydrogen, bonding electrons are somewhat shifted towards carbon, leaving hydrogen atoms with positive partial charges. On the other hand, silicon is somewhat less electronegative than hydrogen and the bonding electrons are shifted towards hydrogen atoms, which adopt slightly negative charges.
Briefly explain why carbon and silicon can form oxides with such different physical properties, gaseous CO2 and solid SiO2.
Carbon atoms are small enough to form π bonds with oxygen due to the overlap of p orbitals, resulting in the formation of double C O bonds. Consequently, CO2 forms individual molecules that interact with each other via weak London dispersion forces. Silicon atoms are too large and form only single bonds with oxygen, four such bonds per each silicon atom, with each oxygen atom bridging between two silicon atoms, resulting in a covalent-network solid.