Concept explainers
(a)
Interpretation:
The hybridization of carbon atoms in carbon nanotubes, and the hybridization of boron and nitrogen atoms in boron nitride nanotubes have to be given.
(a)
Answer to Problem 8.31CE
The hybridization of carbon atoms in carbon nanotubes is
The hybridization of boron atoms in boron nitride nanotubes is
The hybridization of nitrogen atoms in boron nitride nanotubes is
Explanation of Solution
Carbon nanotubes are one-dimensional nanomaterial with density ranging from
Boron nitride nanotubes are a polymorph of boron nitride. They have similar structures to that of carbon nanotubes except that boron and nitride atoms in boron nitride nanotubes replace carbon atoms. Boron nitride nanotube is an electrical insulator. The boron and nitrogen atoms in boron nitride nanotubes are
(b)
Interpretation:
The number of hexagons that must be strung together around the circumference of a nanotube has to be given.
(b)
Explanation of Solution
Each unit in the given nanotube contains two hexagons, therefore, sixteen hexagons per circumference. The number of hexagons that must be strung together around the circumference of a nanotube is eight.
(c)
Interpretation:
The reason why the hydrogenation of Buckminsterfullerene stops at a certain point has to be explained.
(c)
Explanation of Solution
In buckminsterfullerene, the carbon atoms are planar and it is
(d)
Interpretation:
The structure of buckminsterfullerene has to be explained and the reason why boron nitride cannot form spheres has to be given.
(d)
Explanation of Solution
Buckminsterfullerene is a type of fullerene with a formula
The spherical structures require the formation of five-member rings. Boron nitride cannot form these rings because they require high-energy boron-boron or nitrogen-nitrogen bonds.
(e)
Interpretation:
The density of the cubic boron nitride has to be calculated.
(e)
Answer to Problem 8.31CE
The density of the cubic boron nitride is
Explanation of Solution
Given,
Edge length of the unit cell is
The number of atoms in the unit cell of face-centered cubic cell is four.
The mass of four atoms in the unit cell is calculated from the molar mass of boron nitride and
Mass=
The volume of the cubic unit cell is the length of the edge raised to its third power. The volume is calculated as,
The density is calculated as,
The density of the cubic boron nitride is
(f)
Interpretation:
The form of boron nitride that is favored at high pressures has to be given.
(f)
Answer to Problem 8.31CE
At high pressures, the cubic form of boron nitride is more favored.
Explanation of Solution
Cubic boron nitride is formed by high pressure, high temperature treatment of hexagonal boron nitride.
Cubic form of boron nitride is analogue to structure of diamond.
Hexagonal form of boron nitride is analogue to structure of graphite.
At high pressures, the cubic form of boron nitride is more favored since it is analogous to the structure of diamond.
Want to see more full solutions like this?
Chapter 8 Solutions
Chemical Principles: The Quest for Insight
- Account for the following :(a) Glass objects from ancient civilizations are found to become milky in appearance.(b) Window glass panes of old buildings are thicker at the bottom than at the top.arrow_forwardThe following figures represent the binary hydrides of the elements of the second period of the p block. A) Identify the different hydrogen atom in each case and write the molecular formula of each hydride. Explain your answer. B) Perform step-by-step hybridization for each one.arrow_forwardIn the mountains, water in an open container will boil when(a) its critical temperature exceeds room temperature.(b) its vapor pressure equals atmospheric pressure.(c) its temperature is 100 °C.(d) enough energy is supplied to break covalent bonds.(e) none of these is correct.arrow_forward
- Silicon carbide (SiC) is made by the high-temperature reaction of silica sand (quartz) with coke; the byproduct is carbon monoxide.(a) Write a balanced chemical equation for this reaction.(b) Calculate the standard enthalpy change per mole of SiC produced.(c) Predict (qualitatively) the following physical properties of silicon carbide: conductivity, melting point, and hardness.arrow_forwardSketch the structure of how the silicon atoms in the mineral hedenbergite, FeCaSi2O6, are connected to oxygen atoms.arrow_forwardProvide the Lewis structure and molecular geometry as predicted by VSEPR (with solution) of the following: (b) Sulfur tetrafluoride, SF4arrow_forward
- Draw the Lewis structures for the phosphorus halides PCl3 and PCl5 . Describe their VSEPR shape.arrow_forwardThe elements sodium, aluminum, and chlorine are in the same period.(a) Which has the greatest electronegativity?(b) Which of the atoms is smallest?(c) Write the Lewis structure for the simplest covalent compound that can form between aluminum and chlorine.(d) Will the oxide of each element be acidic, basic, or amphoteric?arrow_forward4. (a) Draw the shape of the atomic valence orbitals formed by the overlaping of two fluoride 2p atomic orbitals. (b) Draw the molecular orbital diagrams for F2 and F2*. Identify their bond order and magnetic properties. (c) An unstable nucleus exhibit radioactivity. (i) Explain how the number of protons and neutrons in a radioactive nucleus can be used to predict its probable mode decay. (ii) Illustrate your answer in (i) with a schematic graph.arrow_forward
- The valuable polymer polyurethane is made by a condensationreaction of alcohols (ROH) with compounds that containan isocyanate group (RNCO). Two reactions that cangenerate a urethane monomer are shown here: (a) Which process, i or ii, is greener? Explain.(b) What are the hybridization and geometry of the carbonatoms in each C-containing compound in each reaction?(c) If you wanted to promote the formation of the isocyanateintermediate in each reaction, what could you do,using Le Châtelier’s principle?arrow_forwardDescribe the hybridization of silicon and the molecular structure of the following molecules and ions:(a) (CH3)3SiH(b) SiO44−(c) Si2H6(d) Si(OH)4(e) SiF62−arrow_forwardThe average daily mass of O2 taken up by sewage dischargedin the United States is 59 g per person. How many liters ofwater at 9 ppm O2 are 50 % depleted of oxygen in 1 day by apopulation of 1,200,000 people?arrow_forward
- Chemistry: Principles and PracticeChemistryISBN:9780534420123Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward MercerPublisher:Cengage Learning