Exam 3 Study Guide
Give balanced equations for 2 preparations of ammonia.
1. N2 + 3H2---> 2NH3 2. Li3N + 3H2O---> NH3 + 3LiOH
write the full chemical reaction fort he extraction of elemental sodium from sodium chloride. Be sure to balance the equation and include phases.
2NaCl(l)------> 2Na(l) + Cl2 (g) electrolysis reaction
Complete the reactions of Sn(II) and Sn(IV), and be sure that the reaction are balanced. Do not include phases. If no reaction occurs, leave the products side of the equation blank
1. SnCl2 + PbCl4----> SnCl4 + PbCl2 2. SnCl4 + PbCl2-----> (no rxn) Select true statements about the rxns: 1. the inert pair effect renders Pb(II) as the more stable oxidation state of lead. 2. Sn(IV) is the most stable oxidation state of tin
What are the molar masses of 1H2O, D2O, and T2O? the average mass of O is 15.999 g/mol name----symbol----mass(amu or g/mol protium---1H---------1.0078 deuterium---2H or D-----2.0141 tritium-----3H or T-------3.0160
1H2O: 18.02 g/mol D2O: 20.03 g/mol T2O: 22.03 g/mol
estimate the mass of carbon needed to deposit an atom thin layer of graphene onto a silicon wafer that is 51.0 mm in diameter. The atomic radius of a carbon atom is 77.0 pm. Assume there is no space between adjacent atoms
2.19x 10^-6 g
what is the molar mass of water on a fiction planet where hydrogen is made of 27.0% protum, 21.0% deuterium, and 52.0% tritium
20.53 g/mol
what is the best efficiency rating that a present-day, coal-fired power plant can achieve?
40%
classify these oxides as acidic, basic, or amphoteric
Acidic: N2O5, Cl2O7 Basic: Li2O, BaO Amphoteric: Al2O3
Nitrogen cycle
Atmospheric nitrogen (N2) is converted to NH3 in a process catalyzed by nitrogenase. NH4+ is oxidized to NO2- and then NO3- in a process called nitrification. Atmospheric nitrogen is reduced to NH4+ as a result of nitrogen fixation. Nitrate is converted to N2 in a process called denitrification. Nitrite conversion to NH4+ is catalyzed by nitrite reductase.
Identify the group 3A element that best fits each description
Boron: a semiconductor, forms a molecular fluoride, the most electronegative, forms an acidic oxide Aluminum: the most abundant element in the group, the most abundant metal in the earth's crust Gallium: used in electrical resistance thermometers called thermistors Thallium: stable in the +1 oxidation state, extremely toxic
Hydrolysis of 1 mol of a borohydride gives 5 mol B(OH)3 and 12 mol H2. Write the full balanced reaction. Do not include the phases
B5H9 + 15H2O--->5B(OH)3 + 12H2 nido
which element in group 2 is the most metallic in character?
Ba
which element in group 2 reacts the most vigorously?
Ba
selec the reasons why some of beryllium's properties are unlike those of other group 2 metals and closer to those of some group 12 and 13 metals
Be2+ is strongly polarizing Beryllium has a higher electronegativity than other group 2 metals Beryllium has a relatively small metallic and ionic radius
select the property that is a characteristic of the group 13 (3A) element boron
Boron forms binary compounds that contain a delocalized electron pair over three atoms. Their enthalpies of combustion are highly exothermic and the have been proposed for use as jet fuel.
write balanced equation of the hydrolysis of solid calcium phosphide producing phosphine gas, PH3(g) and calcium hydroxide.
Ca3P2(s) + 6H2O(l)---> 2PH3(g) + 3Ca(OH)2(aq)
assign each soli ionic compound to the correct structure type
CsCl: simple cubic NaCl: face centered cubic the larger size of the Cs+ ion and the lower carion-to-anion radius ratio of NaCl
Determine the class of each group 15 element at room temperature
Diatomic gas: nitrogen Solid nonmetal: phosphorus Metalloid: arsenic, antimony True metal: bismuth
write IUPAC names
H2Te: tellane HBr: hydrogen bromide
which of these hydrogen halides is capable of hydrogen bonding when dissolved in water?
HF
select the explanation for why the boiling point of HF doe snot follow the observed trend of the other three hydrogen halides.
HF exhibits hydrogen bonds, whereas the other hydrogen halides exhibit London dispersion forces.
Arrange the species according to the oxidation state of nitrogen in each. Highest refers to the most positive oxidation state of nitrogen, whereas the lowest refers to the most negative oxidation state of nitrogen
Highest NO3- NO2- N2 NH2OH NH4+ Lowest
choose the compounds in which the central metal cation exhibits the inert-pair effect.
InF SnBr2 TlF PbBr2
name the hydrate with formula LiOH * H2O
Lithium hydroxide monohydrate
Predict the structure of the group 13 compounds. Place them into the appropriate caegory
Monomer: BCl3(g) Dimer: BH3(g), GaCl(l) Polymer: n/a
Predict the relative covalent character of the given chromium halide
Most covalent Chromium(VI) fluoride Chromium (III) fluoride Chromium(II) fluoride Least covalent
Determine the oxidation number of nitrogen based on the given reaction: NH4+(aq) +NO2-(aq)---> N2(g) + 2H2O(l)
NH4+: -3 NO2-: +3 N2: 0 reducting agent: NH4+ oxidizing agent: NO2-
complete the given reactions for the extraction of elemental potassium and cesium
Na(l) + KCl(l)--->NaCl(l) + K(g) Ca + 2CsCl(l)----> 2Cs(s) + CaCl2(s) reduction reaction
when alkali metals are heated in an excess of oxygen, the primary product formed depends on the metal itself. Match the metal with its primary metal oxide product, where M denotes the alkali metal.
Oxide, M2O: Li Peroxide, M2O2: Na Superoxide, MO2: K, Rb, Cs
write balanced equation of solid white phosphorus, P4(s), reacting with excess chlorine gas to produce solid phosphorus pentachloride
P4(s) + 10Cl2(g)----> 4PCl5(s)
write the balanced chemical equation for the standard enthalpy of formation of P4O10(s). Be sure to include phases
P4(s) + 5O2(g) -----> P4O10(s) select allotrope of phosphorus that is used to calculate the standard enthalpy formation of P4O10(s) white
write balanced equation of liquid phosphorus trichloride reacting with water to produce hydrochloric acid and phosphorus acid
PCl3(l) + 3H2O(l)----> 3HCl(aq) + H3PO3(aq)
the only acid that will react with silica, SiO2, is HF. The products of the reaction are water and a compounds containing Si and F. Write the balanced equation for this reaction
SiO2 + 4HF----> 2H2O + SiF4
Give the balanced equation for the recovery of silicon from its oxide ore. Phases optional
SiO2 +2C----> Si + 2CO
write the chemical equation for the industrial production of elemental silicon at 2000*C. Include the physical state of each reactant and product.
SiO2(l) + 2C(s) -----> Si(l) + 2CO(g)
write IUPAC name for given compounds
SnH4: Stannane SbH3: Stibane
Predict the Bronsted acidities of the given boron hydrides and arrange them according to their relative Bronsted acidities
Strongest B10H16 B8H14 B6H12 B4H10 Weakest
Predict the relative Lewis acid strength of the group 13 trihalides towards a hard Lewis base. Arrange the compounds according to their relative Lewis acidity
Strongest BCl3 BF3 AlCl3 GaCl3 Weakest
Predict the relative Lewis acid strength of the group 13 trihalides towards a soft Lewis base. Arrange the compounds according to their relative Lewis acidity
Strongest GaCl3 AlCl3 BCl3 Weakest
categorize as true or false
True: group 15 contains 3 different classes of elements, arsenic is used in the electronic industry False: white phosphorus exists as P2 at 25*C and 1atm, nitrogen fixation is the conversion of NH3 into N2, bismuth(V) compounds are often used as reducing agents
use the electronegativity table and the Ketelaar triangle to classify the type of bonding in each group 2 halide.
covalent: n/a ionic: CaBr2, BaBr2 polar covalent: BeBr2
use the ion radius ratio to predict the structure type and coordination number of the compounds
ZnS structure, 4-coordinate: BeTe NaCl structure, 6-cooredinate: CaTe, BaTe CsCl structure, 8-coordinate: n/a
What happens when the elements in group 2 react with iodine?
a salt is formed with the general formula MI2
which of the choices has a carbon footprint? a seven-year-old child a university a banana a boat a garage sale all of the above
all of the above
select the property that is a characteristic of the group 13 (3A) element aluminum
aluminum is one of the most abundant metals in the Earth's crust, and impure forms of its oxide produce gemstones such as ruby and sapphire.
the primary use of nitrogen is as a starting material to produce what compound?
ammonia
what happens when the elements in group 2 react with oxygen?
an oxide is formed with the general formula MO
Using Wade's rules, select the correct classification of the compound B5H11 and enter the total number of skeletal electrons.
arachno total number of skeletal electrons: 16
which of the gases are primarily obtained from the atmosphere?
argon, nitrogen, and oxygen
classify these oxides as acidic, basic amphoteric, or neutral
basic: BaO, Cs2O acidic: SiO2, Cl2O7 amphoteric: Al2O3, PbO2 neutral: CO, NO
Complete and balance the equations for the reactions of the carbonate and orthosilicate salts with acid at temperature and pressure. Include phases
carbonate salt with acid: Li2CO3 (s) + 2HCl(aq)---> 2LiCl(aq) + CO2(g) + H2O (l) orthosilicate salt with acid: Li4SiO4(s) + 4HCl(aq)---> 4LiCl(aq) + SiO2(s) +2H2O(l)
Using Wade's rules, select the correct classification of the compound [B8H8]2- and enter the total number of skeletal electrons.
closo Total number of skeletal electrons: 18
Assuming that both reactions got o completion, calculate the maximum concentration of NO2 that can be released into the atmosphere without allowing the concentration of ozone to rise about 120micrograms/m3
concentration 2.5x10^-6 In which region of the electromagnetic spectrum does light with a wavelength of 420nm lie? visible
what is the major impurity in silicon used to make semiconductors?
elements with one more or one fewer valence electron than silicon
Write the balanced chemical equation for each reaction. nitrogen dioxide reacts with water droplets in the atmosphere to produce nitric acid and nitrous acid.
equation: 2NO2(g) + H2O(l)---> HNO3(aq) + HNO2(aq) Photodissociation uses light to break down nitrogen dioxide gas: NO2(g) --light--> NO(g) + O(g)
write the formula of the salt formed in the reaction of copper(II) oxide with hydrochloric acid
formula: CuCl2 name: copper(II) chloride
When lithium nitride, Li3N(s), is treated with water, H2O(l), ammonia, NH3(g), is produced. Predict the formula of the gas produced when sodium phosphide, Na3P(s) is treated with water
formula: PH3 balanced equation: Na3P +3H2O--->3NaOH + PH3
Which of the substances are allotropes of carbon?
graphite, diamond, and fullerenes
the carbon footprint of an object is a measure of the total amount of
greenhouse gases that are emitted from producing or using the object
In what group of the periodic table would you place element 117, "topaline", which is reported to have been discovered on Ganymede in 2021?
group: 17(7A) predict formula of magnesium and topaline and name compound: formula: MgTo2 name: Magnesium topalide
What happens when the elements in group 2 react with water?
hydrogen gas is released
select the property that is a characteristic of the group 13(3A) element gallium
if held in the hand, solid gallium will melt.
classify the hydrides as ionic (saline), covalent (molecular), or metallic
ionic: LiH, CaH2 Covalent: B2H6, SiH4, SbH3, H2Se, HBr metallic: TiH2, TiH1.7
identify the property that is a characteristic of the group 14(4A) element tin
it converts from a metallic allotrope to a diamond-like allotrope below 18*C
select the property that is characteristic of the group 14(4A) element silicon
it forms extended compounds with alternating oxygen-silicon single bonds that are prevalent in Earth's crust.
select the property that is a characteristic of the group 14(4A) element lead
lead is a malleable element that was commonly used for plumbing and cookware.
which element is found in high quantities as an ion in sea water, and primarily produced through an industrial process that begins by precipitation of the element from sea water?
magnesium
acid rain composed of sulfuric acid can form as a result of the combustion of coal.... burning 703kg of each type of coal type--C%----H%----O%-----S% bituminous--81--6--8--5 anthracite---93---3--3--1
mass of H2SO4 from bituminous coal: 272kg mass of H2SO4 from anthracite: 57.4 kg
use the electronegativity table and the Ketelaar triangle to determine the type of bonding in LiCa
metallic bonding occurs.
arrange the metal oxides according to their basicity, where is a generic transition metal
most basic M2O MO M2O3 MO2 MO3 least basic
Using Wade's rules, select the correct classification of the compound B5H9 and enter the total number of skeletal electrons.
nido total number of skeletal electrons: 14
identify compounds as oxides, peroxides, or superoxides.
oxides: SrO, Li2O peroxides: BaO2, Na2O2 superoxides: CsO2, RbO2
classify these ions and allotropes of oxygen according to whether they can be oxidized, reduces, or both
oxidized only: oxide, O^2- reduced only: n/a oxidized or reduced: peroxide, (O2)^2- superoxide, (O2)- oxygen, O2 ozone, O3
calculate the percent carbon in coal (C135H96O9NS) by mass
percent carbon 85%
Astatine is a radioactive halogen that concentrated in the thyroid gland. Predict several properties.
physical state at 25*C: solid formula of sodium astatide (w phase): NaAt(s) formula of gaseous astatine (w phase): At2(g) color of sodium astatide: white color of solid astatine: black
the superoxide ion, peroxide ion, and oxide ion can be thought of as arising from oxygen by the transfer of the appropriate number of electrons to O2
potassium superoxide: KO2 potassium peroxide: K2O2 potassium oxide: K2O
in addition to energy generation, coal is also used for which purpose?
production of iron and steel, and chemicals for medical use.
the reactions shown are part of the Dow process, which is used to recover magnesium from sea water. Complete the reactions by replacing the question marks and balance the reactions in both mass and charge.
rxn 1. Mg2+(aq) + 2OH-(aq)---> Mg(OH)2(s) rxn2. 2Cl-(l)-----> Cl2(g) + 2e- rxn3. Mg2+ (l) + 2e- -----. Mg(l)
select the property that is a characteristic of the group 14(4A) element carbon
several allotropes of the pure element exist.
classify each of the hydride compounds as a solid, liquid, or gas at room temp
solid: n/a liquid: water gas: silane, arsine, hydrogen selenide, hydrogen iodide
categorize each statement as true or false
true: group 14 contains 3 different classes of elements, group1 carbides are ionic compounds false:4-coordinate silicon compounds tend to prefer a square planar geometry, diamond is the most thermodynamically stable allotrope of carbon, zeolite aluminosilicates are the primary component of clay
assign structure to the correct phosphorus allotropes
white phosphorus: pyramid-like red phosphorus: chain of pyramids black phosphorus: blanket-like
