2. It has a boiling point of 128.40 K and a melting point of 49.3 K. It has a molar mass of 53.996 g/mol and a density of 1.88 g/l as a gas at room temperature. Each iodine atom contributes seven electrons and the negative charge one, so the Lewis electron structure is. b. Predict the geometry of allene (H2C=C=CH2), a compound with narcotic properties that is used to make more complex organic molecules. a. NaCl + CaPO4 The resulting highly exothermic reaction caused a rapid increase in pressure that ruptured the tanks, releasing large amounts of methyl isocyanate that killed approximately 3800 people and wholly or partially disabled about 50,000 others. What is the molecular geometry of ClCN as predicted by the VSEPR theory? VSEPR only recognizes groups around the central atom. PDF I1- Using VSEPR to Predict Shapes of Molecules - Newcastle University ClO2 - Molecular Geometry / Shape and Bond Angles - YouTube b. The nitrogen has 5 outer electrons, plus another 4 from the four hydrogens - making a total of 9. Nitrogen and oxygen belong to periods 5A and 6A groups respectively in the periodic table. These electron-pair bonds determine the positions of the atoms and hence the molecular geometry. Cyanogen chloride is a molecule with the connectivity ClCN. In our discussion we will refer to Figure \(\PageIndex{2}\) and Figure \(\PageIndex{3}\), which summarize the common molecular geometries and idealized bond angles of molecules and ions with two to six electron groups. The VSEPR model can be used to predict the shapes of many molecules and polyatomic ions, but it gives no information about bond lengths and the presence of multiple bonds. 4. e. none of these, 16. There are six nuclei, so the molecular geometry of SF6 is octahedral. The two bonding pairs arrange themselves at 180 to each other, because that's as far apart as they can get. 4. 4. 1. Oxygen has six valence electrons and each hydrogen has one valence electron, producing the Lewis electron structure. Cl2O Molecular Geometry, Bond Angles and Electron Geometry Wayne Breslyn 635K subscribers 7.9K views 1 year ago An explanation of the molecular geometry for the Cl2O (Dichlorine monoxide). Draw the structural formula for each of the following molecules. This linear, triatomic pseudohalogen is an easily condensed colorless gas. A wedge shows a bond coming out towards you. a. Repulsions are minimized by placing the groups in the corners of a trigonal bipyramid. A more advanced way of determining the shape of a compound is electron geometry. They arrange themselves entirely at 90, in a shape described as octahedral. A) linear B) trigonal planar C) V-shaped D) tetrahedral With three bonding pairs and two lone pairs, the structural designation is AX3E2 with a total of five electron pairs. Once again, both groups around the central atom are bonding pairs (BP), so CO2 is designated as AX2. a. e. none of these, 17. For nitrogen to have an octet of electrons, it must also have a lone pair: Because multiple bonds are not shown in the VSEPR model, the nitrogen is effectively surrounded by three electron pairs. Cyanogen chloride is a molecule with the connectivity .mw-parser-output .template-chem2-su{display:inline-block;font-size:80%;line-height:1;vertical-align:-0.35em}.mw-parser-output .template-chem2-su>span{display:block;text-align:left}.mw-parser-output sub.template-chem2-sub{font-size:80%;vertical-align:-0.35em}.mw-parser-output sup.template-chem2-sup{font-size:80%;vertical-align:0.65em}ClCN. Because a multiple bond is counted as a single bond in the VSEPR model, each carbon atom behaves as if it had two electron groups. The central Nitrogen atom forms two double bonds with the adjacent nitrogen atoms. H2S Molecular geometry or shape, electron geometry, Bond angle Reading 'My next . Two species (atoms, molecules or ions) are isoelectronic if they have exactly the same number and arrangement of electrons (including the distinction between bonding pairs and lone pairs). (Carbon is the central atom.). Dianasaurus. This page explains how to work out the shapes of molecules and ions containing only single bonds. D With two nuclei around the central atom and one lone pair of electrons, the molecular geometry of SnCl2 is bent, like SO2, but with a ClSnCl bond angle of 95. For example, carbon atoms with four bonds (such as the carbon on the left in methyl isocyanate) are generally tetrahedral. Be very careful when you describe the shape of ammonia. next section and the total number of electron pairs, find the basic VSEPR shape which is assigned to the molecule. There are four electron groups around the central atom. 2. Six electron groups form an octahedron, a polyhedron made of identical equilateral triangles and six identical vertices (Figure \(\PageIndex{2}\). Chlorine is in group 7 and so has 7 outer electrons. There are two possible structures, but in one of them the lone pairs would be at 90. Chremistry Flashcards | Quizlet A quick explanation of the molecular geometry of ClO2 - (Chlorite ion) including a description of the ClO2 - bond angles. The N=C=O angle should therefore be 180, or linear. Cyanogen chloride - Wikipedia 3. The next two carbon atoms share a triple bond, and each has an additional single bond. 6 electrons in the outer level of the sulphur, plus 1 each from the six fluorines, makes a total of 12 - in 6 pairs. The PO43- ion would break apart into P and O ions and be surrounded by water molecules (This allows for the electrons coming from the other atoms.). With five bonding pairs and one lone pair, BrF5 is designated as AX5E; it has a total of six electron pairs. Check if the VSEPR shape of the molecule is correct by going to the database and examining the crystal structure (the refcode for the [PF 6] Once again, we have a compound that is an exception to the octet rule. These are the only possible arrangements. C) CH4 and H2O 1. It has a total of three electron pairs, two X and one E. Because the lone pair of electrons occupies more space than the bonding pairs, we expect a decrease in the ClSnCl bond angle due to increased LPBP repulsions. With two bonding pairs on the central atom and no lone pairs, the molecular geometry of CO2 is linear (Figure \(\PageIndex{3}\)). It has a 1+ charge because it has lost 1 electron. How many of each atom are in the following medication:Tamiflu: C16H13N2O4-H3PO4C = ___ , H = ___ , N = ___ , O = ____ , P = ____ What is the molecular shape around the carbon indicated by the arrow in the structure of DEET shown below? A) 15.78 M That leaves a total of 8 electrons in the outer level of the nitrogen. Test 3 CHapters 7, 8, & 9. 4. Instead, they go opposite each other. B) 177 g C6H12O6 With two hydrogen atoms and two lone pairs of electrons, the structure has significant lone pair interactions. nursestudytime. This will be determined by the number of atoms and lone pairs attached to the central atom.If you are trying to find the electron geometry for CH3 - we would expect it to be Tetrahedral.Helpful Resources: How to Draw Lewis Structures: https://youtu.be/1ZlnzyHahvo Molecular Geometry and VSEPR Explained: https://youtu.be/Moj85zwdULg Molecular Geo App: https://phet.colorado.edu/sims/html/molecule-shapes/latest/molecule-shapes_en.htmlGet more chemistry help at http://www.breslyn.orgDrawing/writing done in InkScape. Boron is in group 3, so starts off with 3 electrons. Which of the following molecules has a net dipole moment? The negative PO43- ion would be surrounded by the partial positive oxygen of waterV. 1. If we place it in the equatorial position, we have two 90 LPBP repulsions at 90. We expect all FaxialBrFequatorial angles to be less than 90 because of the lone pair of electrons, which occupies more space than the bonding electron pairs. The three equatorial positions are separated by 120 from one another, and the two axial positions are at 90 to the equatorial plane. Which of the following would occur if K3PO4 was dissolved in water?I. 3. 4. This theory is very simplistic and does not account for the subtleties of orbital interactions that influence molecular shapes; however, the simple VSEPR counting procedure accurately predicts the three-dimensional structures of a large number of compounds, which cannot be predicted using the Lewis electron-pair approach. Molecules with polar covalent bonds can have a dipole moment, an asymmetrical distribution of charge that results in a tendency for molecules to align themselves in an applied electric field. a. gold is oxidized and iodine is reduced Work out how many of these are bonding pairs, and how many are lone pairs. The molecular geometry can be described as a trigonal planar arrangement with one vertex missing. Consequently, molecules with these geometries always have a nonzero dipole moment. An explanation of the molecular geometry for the CH3 - ion (Methyl anion) including a description of the CH3 - bond angles. Which of the following is incorrectly matched: Suggested activity #1: Students can get an introductory level idea of approximately what angles are associated with various molecular shapes by exploring the database. Balance the following equation:___ Cr2(SO4)3 + ___ NaOH -> ___ Cr(OH)3 + ___ NaNO3 a. D) 2.70 M, 31. Chem Ch. [13] The CK rocket was never deployed or issued to combat personnel. c. III and IV only 7.77 x 1023 d. 16, 28, 2, 4, 1 The central atom, carbon, contributes four valence electrons, and each hydrogen atom has one valence electron, so the full Lewis electron structure is. Allow for any ion charge. This causes a deviation from ideal geometry (an HCH bond angle of 116.5 rather than 120). The structure with the minimum amount of repulsion is therefore this last one, because bond pair-bond pair repulsion is less than lone pair-bond pair repulsion. CH2F2 Lewis Structure, Molecular Geometry - Techiescientist Carbon is in group 4, and so has 4 outer electrons. 660 mL Count the number of electron groups around each carbon, recognizing that in the VSEPR model, a multiple bond counts as a single group. Because the two CO bond dipoles in CO2 are equal in magnitude and oriented at 180 to each other, they cancel. Lewis electron structures give no information about molecular geometry, the arrangement of bonded atoms in a molecule or polyatomic ion, which is crucial to understanding the chemistry of a molecule. 9: Molecular Geometry and Bonding Theories, Map: Chemistry - The Central Science (Brown et al. The four bonds around carbon mean that it must be surrounded by four bonding electron pairs in a configuration similar to AX4. All electron groups are bonding pairs, so the structure is designated as AX4. 75 mL Like NH3, repulsions are minimized by directing each hydrogen atom and the lone pair to the corners of a tetrahedron. Such is the case for CO2, a linear molecule (Figure \(\PageIndex{8a}\)). We will demonstrate with methyl isocyanate (CH3N=C=O), a volatile and highly toxic molecule that is used to produce the pesticide Sevin. d. 1.29 x 1023 Because there is one hydrogen and two fluorines, and because of the lone pair of electrons on nitrogen, the molecule is not symmetrical, and the bond dipoles of NHF. 4.8: The Shapes of Molecules - Chemistry LibreTexts Nitrogen is in group 5 and so has 5 outer electrons. From this we can describe the molecular geometry. Using this information, we can describe the molecular geometry, the arrangement of the bonded atoms in a molecule or polyatomic ion. Select its Lewis structure., Select the best Lewis structure for ClCN., Thionyl chloride is used as an oxidizing and chlorinating agent in organic chemistry. We must now decide how to arrange the lone pairs of electrons in a trigonal bipyramid in a way that minimizes repulsions. Similarly, the carbon atom on the right has two double bonds that are similar to those in CO2, so its geometry, like that of CO2, is linear. Because of this, there is more repulsion between a lone pair and a bonding pair than there is between two bonding pairs. C) polar covalent Because it is forming 4 bonds, these must all be bonding pairs. c. 2, 6, 2, 3 ClF3 is described as T-shaped. Ammonia is pyramidal - like a pyramid with the three hydrogens at the base and the nitrogen at the top. Use the VSEPR model to predict the molecular geometry of propyne (H3CCCH), a gas with some anesthetic properties. Look at the images below -- which solvent is nonpolar? You have to include both bonding pairs and lone pairs. The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. 9.2: The VSEPR Model - Chemistry LibreTexts A) 0.982 g C6H12O6 Which of the following pairs of molecules can form hydrogen bonds between them? C) 0.555 g C6H12O6 1.74 2. 16, 31, 2, 4, 1 The FaxialSFaxial angle is 173 rather than 180 because of the lone pair of electrons in the equatorial plane. Due to LPLP, LPBP, and BPBP interactions, we expect a significant deviation from idealized tetrahedral angles. Question 37 Indicate the type of hybrid orbitals used by the central atom in CCl4. ", "National Pollutant Inventory Cyanide compounds fact sheet", https://en.wikipedia.org/w/index.php?title=Cyanogen_chloride&oldid=1147491077, This page was last edited on 31 March 2023, at 09:10. To minimize repulsions, the groups are directed to the corners of a trigonal bipyramid. A sample of seawater contains 1.3 g of calcium ions in 3,100 kg of solution. Because the sulfur is forming 6 bonds, these are all bond pairs. SiH4 is the structural composition of silane/silicane. c. 0.0088 mL We expect the concentration of negative charge to be on the oxygen, the more electronegative atom, and positive charge on the two hydrogens. All LPBP interactions are equivalent, so we do not expect a deviation from an ideal 180 in the FXeF bond angle. In previous examples it did not matter where we placed the electron groups because all positions were equivalent. a. 1. In addition, there was significant damage to livestock and crops. This molecular structure is square pyramidal. 3. The central atom, carbon, has four valence electrons, and each oxygen atom has six valence electrons. The Lewis electron structure is. To minimize repulsions the three groups are initially placed at 120 angles from each other. 1, 6, 2, 3 The bromine atom has seven valence electrons, and each fluorine has seven valence electrons, so the Lewis electron structure is. The BrF5 structure has four fluorine atoms in a plane in an equatorial position and one fluorine atom and the lone pair of electrons in the axial positions. Which of the following statements about homogeneous mixtures are false? Introduction H 2 S does not possess any hybridization as per Drago's rule. There are five groups around sulfur, four bonding pairs and one lone pair. This reaction proceeds via the intermediate cyanogen ((CN)2).[4]. A) 84.0 mL ethanol In molecular geometries that are highly symmetrical (most notably tetrahedral and square planar, trigonal bipyramidal, and octahedral), individual bond dipole moments completely cancel, and there is no net dipole moment. For each three-dimensional molecular geometry, predict whether the bond dipoles cancel. It is forming 2 bonds so there are no lone pairs. In 1984, large quantities of Sevin were accidentally released in Bhopal, India, when water leaked into storage tanks. Title: Microsoft Word - Homework-WS4-MolecularGeometry.docx N,N-diethyl-m-tolumide (DEET) is the active ingredient in many mosquito repellents. 8. For example, in a molecule such as CH2O (AX3), whose structure is shown below, the double bond repels the single bonds more strongly than the single bonds repel each other. PDF Unit: Chemical Bonding "Molecular Geometry" - WS #4 That means that you couldn't use the techniques on this page, because this page only considers single bonds. Cyanogen chloride is a highly toxic chemical compound with the formula CNCl. b. This page titled Shapes of Molecules and Ions is shared under a CC BY-NC 4.0 license and was authored, remixed, and/or curated by Jim Clark. This charge polarization allows H2O to hydrogen-bond to other polarized or charged species, including other water molecules. Molecular geometry is the stable shape of the molecule in which molecules exist. They all lie in one plane at 120 to each other. That will be the same as the Periodic Table group number, except in the case of the noble gases which form compounds, when it will be 8. With 18 valence electrons, the Lewis electron structure is shown below. a. e. none of these, 20 . In the next structure, each lone pair is at 90 to 3 bond pairs, and so each lone pair is responsible for 3 lone pair-bond pair repulsions. Recent flashcard sets. It is a flammable and colorless gaseous compound bearing a strong repulsive odor. Oxygen is in group 6 - so has 6 outer electrons. A bond between Rb and F is classified as: We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Give the number of lone pairs around the central atom and the molecular geometry of CBr4, 4. b. Homogeneous mixtures have the same uniform appearance and composition throughout It is forming 4 bonds to hydrogens, adding another 4 electrons - 8 altogether, in 4 pairs. There are two nuclei about the central atom, so the molecular shape is bent, or V shaped, with an HOH angle that is even less than the HNH angles in NH3, as we would expect because of the presence of two lone pairs of electrons on the central atom rather than one. A) 4.2 10-4 ppm Ca2+ ions Each CO bond in CO2 is polar, yet experiments show that the CO2 molecule has no dipole moment. Cyanogen Chloride Enthalpy of Formation - Argonne National Laboratory If you are given a more complicated example, look carefully at the arrangement of the atoms before you start to make sure that there are only single bonds present. spin ON spin OFF; Top contributors to the provenance of f H of ClCN (g) The 20 contributors listed below account only for 80.5% of the provenance of f H of ClCN (g). This molecular shape is essentially a tetrahedron with two missing vertices. Correct Answer: trigonal planar. Haloalkanes or alkyl halides are organic compounds, which contain at least one halogen atom bonded to the carbon atom. The dominant intermolecular forces in octane are: 9. You previously learned how to calculate the dipole moments of simple diatomic molecules. 1. Which molecule(s) has a net dipole moment? 18.35 g/mol 4. The axial and equatorial positions are not chemically equivalent, as we will see in our next example. First you need to work out how many electrons there are around the central atom: Now work out how many bonding pairs and lone pairs of electrons there are: Divide by 2 to find the total number of electron pairs around the central atom. A tetrahedron is a regular triangularly-based pyramid. The molecular geometry or shape of H 2 S is bent, angular or V-shaped. The three nuclei in BrF3 determine its molecular structure, which is described as T shaped. If both are in the equatorial positions, we have four LPBP repulsions at 90. As with SO2, this composite model of electron distribution and negative electrostatic potential in ammonia shows that a lone pair of electrons occupies a larger region of space around the nitrogen atom than does a bonding pair of electrons that is shared with a hydrogen atom. Four electron pairs arrange themselves in space in what is called a tetrahedral arrangement. Like lone pairs of electrons, multiple bonds occupy more space around the central atom than a single bond, which can cause other bond angles to be somewhat smaller than expected. A new rule applies in cases like this: If you have more than four electron pairs arranged around the central atom, you can ignore repulsions at angles of greater than 90. There are actually three different ways in which you could arrange 3 bonding pairs and 2 lone pairs into a trigonal bipyramid. With three lone pairs about the central atom, we can arrange the two F atoms in three possible ways: both F atoms can be axial, one can be axial and one equatorial, or both can be equatorial: The structure with the lowest energy is the one that minimizes LPLP repulsions. Thus the lone pairs on the oxygen atoms do not influence the molecular geometry. d. both gold and iodine are oxidized It shows how the molecules exist which helps to determine different physical and chemical properties of the molecules. 100% (3 ratings) The molecular shape is line . The three lone pairs of electrons have equivalent interactions with the three iodine atoms, so we do not expect any deviations in bonding angles. 1. e. none of these, 22. Phosphorus (in group 5) contributes 5 electrons, and the five fluorines 5 more, giving 10 electrons in 5 pairs around the central atom. 1. 1. The terminal carbon atoms are trigonal planar, the central carbon is linear, and the CCC angle is 180. c. 5.0 mg/mL Look at the following redox reaction and choose the correct statement: 2 Au3+ (aq) + 6 I- -> 2 Au (s) + 3 I2 (s) d. 453.2 grams 31 terms. If the individual bond dipole moments cancel one another, there is no net dipole moment. The shape will be identical with that of XeF4. and more. Select the best Lewis structure for SOCl2. As you learned previously, the Lewis electron structure of one of three resonance forms is represented as. B There are four electron groups around oxygen, three bonding pairs and one lone pair. Predict the ideal bond angles in GeCl4 using the molecular shape given by the VSEPR theory. What volume of ethanol is in a 750.-mL bottle of this wine? e. none of these are correct, 15. Ant Man requires 3.25 grams of growth pills containing pym particles. a. Winnie the Pooh has 1.29 mol of heffalumps. c. both gold and iodine are reduced It is a colorless gas at standard temperature and pressure. Structure (b), with fewer LPBP repulsions at 90 than (a), is lower in energy. The other fluorine (the one in the plane) is 120 away, and feels negligible repulsion from the lone pairs. D) dipole-dipole Although there are lone pairs of electrons, with four bonding electron pairs in the equatorial plane and the lone pairs of electrons in the axial positions, all LPBP repulsions are the same. 2.0 mg/ml a. I and IV only It is important that you understand the use of various sorts of line to show the 3-dimensional arrangement of the bonds. Legal. C From B, XeF2 is designated as AX2E3 and has a total of five electron pairs (two X and three E). It's useful to study molecular geometry to get information beyond that provided in a Lewis structure. What is the molecular geometry around the carbons in CCl2CH2 as predicted by the VSEPR theory? To predict whether a molecule has a dipole moment. The shape of a molecule or ion is governed by the arrangement of the electron pairs around the central atom. NH4+ is tetrahedral. The intermolecular forces present in CH3NH2 include which of the following? Using the VSEPR model, predict the molecular geometry of each molecule or ion. B) CH3OH and NH3 This designation has a total of three electron pairs, two X and one E. Because a lone pair is not shared by two nuclei, it occupies more space near the central atom than a bonding pair (Figure \(\PageIndex{4}\)). The bond pairs are at an angle of 120 to each other, and their repulsions can be ignored. The molecule is described as being linear. b. To choose between the other two, you need to count up each sort of repulsion. Finally, you have to use this information to work out the shape: Arrange these electron pairs in space to minimize repulsions. In the diagram, the other electrons on the fluorines have been left out because they are irrelevant. e. All of the statements shown are correct, 27. For example, if the ion has a 1- charge, add one more electron. Draw each one (using circles and lines from class). Correct Answer: XeO3. It is a colorless gaseous compound exhibiting a strong peculiar odor and acts as an oxidizer. 1. Figure 8.6. Figure \(\PageIndex{6}\): Overview of Molecular Geometries. One of the limitations of Lewis structures is that they depict molecules and ions in only two dimensions. With only bonding pairs, SF6 is designated as AX6. 3. ( CK12 Licence) d. 1.96 x 1024 If one lone pair is axial and the other equatorial, we have one LPLP repulsion at 90 and three LPBP repulsions at 90: Structure (c) can be eliminated because it has a LPLP interaction at 90. Because it is forming 3 bonds there can be no lone pairs. What is the molecular geometry of ClCN as predicted by the VSEPR theory? The molecular geometry of PCl5 is trigonal bipyramidal, as shown in Figure \(\PageIndex{3}\). a. The Lewis electron-pair approach can be used to predict the number and types of bonds between the atoms in a substance, and it indicates which atoms have lone pairs of electrons. As a result, the CO2 molecule has no net dipole moment even though it has a substantial separation of charge. e. 1.1 mL. 1. Thus according to the VSEPR model, the CN=C fragment should be bent with an angle less than 120. 122 terms. 3. 3. Molecule/Rough copy Lewis Structure Molecular Geometry (Shape) d) CCl 4 e) OCH 2 f) SbCl 5 g) PF 3 h) CH 2Br 2 i) ClCN . e. 450 mg/mL, 33. 11. Although the electron pair arrangement is tetrahedral, when you describe the shape, you only take notice of the atoms. 4. 3. Chlorine is in group 7 and so has 7 outer electrons. 1. Draw the Lewis electron structure of the molecule or polyatomic ion. Anything else you might think of is simply one of these rotated in space. That forces the bonding pairs together slightly - reducing the bond angle from 109.5 to 107. There are five groups around the central atom, three bonding pairs and two lone pairs. Course Hero has all the homework and study help you need to succeed! B) non-polar Two of these electron pairs are bonding pairs and two are lone pairs, so the molecular geometry of \(\ce{H2S}\) is bent (Figure \(\PageIndex{6}\)). Thus BeH2 is designated as AX2. d. Alcoholic beverages; solution 2. Xenon forms a range of compounds, mainly with fluorine or oxygen, and this is a typical one. The concentration of an adrenalin chloride solution, used to treat acute allergic responses, is 15 mg in 30. mL. 226.6 grams It forms bonds to two chlorines, each of which adds another electron to the outer level of the beryllium. The positive K+ ion would be surrounded by the partial negative oxygen of waterII. 3: Boron trifluoride bonding. Because the carbon atom on the left is bonded to four other atoms, we know that it is approximately tetrahedral. a. Pastured milk is an example of a homogeneous mixture e. None of the answer choices would be correct, 28. Since the phosphorus is forming five bonds, there can't be any lone pairs. Predict the products of the following double replacement reaction:Na3PO4 + CaCl2 --> ______ + ______ If they do not, then the molecule has a net dipole moment. The Azide Lewis structure comprises three Nitrogen atoms. b. c. 1.74 x 1023 Lone pairs are in orbitals that are shorter and rounder than the orbitals that the bonding pairs occupy. The valence-shell electron-pair repulsion (VSEPR) model allows us to predict which of the possible structures is actually observed in most cases. But take care! Add one electron for each bond being formed. Each group around the central atom is designated as a bonding pair (BP) or lone (nonbonding) pair (LP). 0.0723 Difluoroamine has a trigonal pyramidal molecular geometry. Methane and the ammonium ion are said to be isoelectronic. Keep in mind, however, that the VSEPR model, like any model, is a limited representation of reality; the model provides no information about bond lengths or the presence of multiple bonds.