Search found 39 matches
- Sat Dec 08, 2018 2:52 pm
- Forum: Amphoteric Compounds
- Topic: How is NH in thymine amphiprotic?
- Replies: 1
- Views: 711
How is NH in thymine amphiprotic?
In question 12.127 in the 6th edition, it is determined that the 2 NHs in thymine are amphiprotic because they can gain or give a proton. But why would NH lose an H if it would give N a negative charge?
- Sat Dec 08, 2018 2:35 pm
- Forum: Lewis Acids & Bases
- Topic: Boric acid acidity
- Replies: 1
- Views: 297
Boric acid acidity
As given in question 12.119 from the 6th edition, it is determined that B(OH)2 acts as a lewis acid as it accepts electron pairs OH from water. But in the solutions manual is also says that its acidity is not due to its dissociation. What does that mean in this context? Is that in reference to it be...
- Sat Dec 08, 2018 2:32 pm
- Forum: Bronsted Acids & Bases
- Topic: Bronsted base, Lewis acid
- Replies: 2
- Views: 344
Bronsted base, Lewis acid
Is it possible for something to act as both a bronsted base and a lewis acid? As B(OH)2 accepts electron pairs (OH) from water, it also accepts the OH atoms. Or does bronsted base exclusively refer to unattached H protons?
- Sat Dec 08, 2018 2:31 pm
- Forum: Bronsted Acids & Bases
- Topic: Bronsted base, Lewis acid
- Replies: 1
- Views: 287
Bronsted base, Lewis acid
Is it possible for something to act as both a bronsted base and a lewis acid? As B(OH)2 accepts electron pairs (OH) from water, it also accepts the OH atoms. Or does bronsted base exclusively refer to unattached H protons?
- Sat Dec 08, 2018 2:24 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Electron donating properties of CH3 [ENDORSED]
- Replies: 1
- Views: 665
Electron donating properties of CH3 [ENDORSED]
For question 12.53 in the 6th edition, its asks where CH3COOH or CH2O2 is the stronger acid. The solutions manual says the CH2O2 is because CH3 has electron donating properties which makes it less electron withdrawing than H. But how is CH3 electron withdrawing? Couldn't it be the case that C is mor...
- Sat Dec 08, 2018 11:33 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Tetrahedral and Square Planar Complexes
- Replies: 1
- Views: 198
Tetrahedral and Square Planar Complexes
How do we tell the difference between a tetrahedral and square planar complex when looking at a coordination compound, since both imply 4 bonds?
- Fri Dec 07, 2018 1:02 am
- Forum: Bronsted Acids & Bases
- Topic: Exceptions: HSO4- and H2PO4-
- Replies: 4
- Views: 1197
Exceptions: HSO4- and H2PO4-
Why is it that HSO4- and H2PO4- act as acids unlike other anions? Is it more favorable somehow?
- Sun Dec 02, 2018 5:32 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: French Toast 28
- Replies: 3
- Views: 580
Re: French Toast 28
Also according to the calculation for dipole moment, (u = q x d) in which d stands for distance, the greater the bond length the greater the dipole moment/polarity that characterizes strong acids (in consideration of the electronegativities of the atoms).
- Sun Dec 02, 2018 5:25 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Strong acids
- Replies: 2
- Views: 349
Re: Strong acids
Strong acids are completely ionized in water, so strong acids have large dipole moments that make them more polar so that the corresponding partial negative and partial positive charges are separated by the water molecule. An increase in electronegativity makes for a greater dipole moment. And accor...
- Sun Dec 02, 2018 5:16 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Definition of Ligand
- Replies: 2
- Views: 284
Definition of Ligand
I'm having a little trouble understanding the concept of a ligand. Is it only considered to be the molecule or atom that forms coordinate covalent bonds? Are there certain molecules that can only form coordinate covalent bonds and are therefore considered ligands or are ligands conditional and molec...
- Tue Nov 27, 2018 2:17 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Polarizability and Bond Strength
- Replies: 2
- Views: 1149
Polarizability and Bond Strength
Does greater polarizability of an atom result in a stronger bond? If so how is that higher polarizability would also make an ionic bond have more covalent character, if ionic bonds are stronger than covalent ones?
- Tue Nov 27, 2018 2:13 pm
- Forum: Hybridization
- Topic: Hybrid Orbitals
- Replies: 3
- Views: 758
Hybrid Orbitals
Do all atoms have hybrid orbitals within a molecule?
- Tue Nov 27, 2018 2:08 pm
- Forum: Hybridization
- Topic: Lone Electrons and Hybridization
- Replies: 3
- Views: 560
Lone Electrons and Hybridization
Do lone electrons (like in radicals) count as an area of electron density and therefore contribute to hybridization? Because the solutions manual for question 4.35 in the 6th edition, it says that the hybrid orbital for Se in SeF3+ is sp3 and not dsp3.
- Sat Nov 24, 2018 6:31 pm
- Forum: Hybridization
- Topic: B3N3H6 Lewis Structure and Hybridization (6th ed. 4.81)
- Replies: 1
- Views: 367
B3N3H6 Lewis Structure and Hybridization (6th ed. 4.81)
B3N3H6 has a similar hexagonal structure to benzene (C6H6). Why is it that there are double bonds between B and N in the lewis structure, instead of having lone pairs attached to the N atoms so that the formal charge of all the atoms would be 0? This would change the hybridization of N from sp^2 to ...
- Sat Nov 24, 2018 6:24 pm
- Forum: Dipole Moments
- Topic: *Hydrogen Bonding
- Replies: 2
- Views: 405
*Hydrogen Bonding
Do hydrogen bonds occur between H atoms and only O, F, or N atoms (since there are the most clearly electronegative)? Is a lone pair on the electronegative atom necessary for hydrogen bonding to occur? And if so, why? Can't there be an attraction between the hydrogen atom and the electronegative ato...
- Sat Nov 24, 2018 6:21 pm
- Forum: Hybridization
- Topic: Hybrid Orbitals and Sigma/Pi Bonds
- Replies: 1
- Views: 235
Hybrid Orbitals and Sigma/Pi Bonds
Are hybrid orbitals independent of sigma and pi bonds? Or is there some kind of pattern or relation between the two?
- Sun Nov 18, 2018 9:01 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Resonance Structures and bond angles
- Replies: 4
- Views: 2263
Resonance Structures and bond angles
Do resonance structures have any effect on bond angles? Along the same lines, does bond length have any correlation to bond angle?
- Sun Nov 18, 2018 8:51 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Angles Less Than a Certain Value
- Replies: 4
- Views: 508
Re: Angles Less Than a Certain Value
To add on to the previous reply, for example, a molecule with a tetrahedral shape that has all bonding pairs may have bond angles of 109.5, but replace one of those bonding pairs with a lone pair and the bond angles will decrease because lone pairs repel bonding pairs more than bonding pairs repel o...
- Sun Nov 18, 2018 8:45 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape Patterns
- Replies: 5
- Views: 600
Molecular Shape Patterns
When it comes to determining molecular shapes of formulas, must we memorize the conditions of each shape, or are there any patterns or trends in molecular shapes that we can look to to help us determine them, without necessarily having to memorize each shape independently?
- Thu Nov 08, 2018 8:24 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Lengths with Larger Atoms
- Replies: 1
- Views: 1248
Bond Lengths with Larger Atoms
Conceptually, how is it that larger atoms result in longer bond lengths? Can it generally be said that larger atoms have lower electronegativities and therefore pull less on neighboring electrons?
- Thu Nov 08, 2018 8:15 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability vs. Polarizing Power
- Replies: 2
- Views: 310
Polarizability vs. Polarizing Power
What's the difference between polarizability and polarizing power? Are they always associated with each other, or can one exist independently of another in an interaction? (ex. cations and anions)
- Thu Nov 08, 2018 8:10 pm
- Forum: Dipole Moments
- Topic: Dipole vs. Hydrogen Bonds
- Replies: 2
- Views: 315
Dipole vs. Hydrogen Bonds
How are dipole interactions weaker than hydrogen bonds, even though dipole interactions involve polar molecules?
- Sun Nov 04, 2018 4:01 pm
- Forum: Administrative Questions and Class Announcements
- Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
- Replies: 121
- Views: 20066
Re: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
How is that for the Lewis structure of N2O (question 12c), N can have more than 3 bonds?
- Thu Nov 01, 2018 10:23 pm
- Forum: Octet Exceptions
- Topic: Odd Lewis Structures
- Replies: 3
- Views: 409
Re: Odd Lewis Structures
I read in a previous post that Dr. Lavelle had explained that Boron cannot have a full octet in this case because any double bonds would give fluorine a formal charge of 1-. Furthermore, the formal charge of Boron is zero (without having double bonds), even though it has 6 and not 8 electrons, becau...
- Thu Nov 01, 2018 9:42 pm
- Forum: Lewis Structures
- Topic: Lewis Structures (w/ same formal charge but different bonds)
- Replies: 2
- Views: 327
Re: Lewis Structures (w/ same formal charge but different bonds)
In the case of (CN)^-, I don't believe it can be written as a double bond because that would result in a total electron count of 12, when the formula only accounts for 10 (C: 4e + N: 5e + (-): 1e). Even if a double bond could exist between the two atoms, the formal charge would be 3- and not the nee...
- Thu Nov 01, 2018 9:23 pm
- Forum: Octet Exceptions
- Topic: ClO2 Radical
- Replies: 1
- Views: 260
ClO2 Radical
For the lewis structure of ClO2, in which Cl has an unpaired electron so that the oxygen atoms may have an octet, is the whole molecule then considered a radical? or just Cl? And what does this mean in terms of its chemical properties?
- Sun Oct 28, 2018 1:44 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Magnetic Spin Number
- Replies: 5
- Views: 435
Re: Magnetic Spin Number
I think that when we refer to parallel spin, we refer to it as in different subshells (e.g. px, py, pz). I'm not sure if this would be different if the atom was at an excited state, but since we learned that no two electrons can have the same four quantum numbers in an atom, I would assume not.
- Sun Oct 28, 2018 1:30 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration for Tungsten
- Replies: 1
- Views: 107
Electron Configuration for Tungsten
The electron configuration for tungsten is [Xe](4f^14)(5d^4)(6s^2). Why is that we move from 4f straight to 5d and bypass 5s and 5p? How would 4f have higher energy than 5s and 5p when it has a lower quantum principal number?
- Sun Oct 28, 2018 1:20 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configs from Periodic Table
- Replies: 1
- Views: 61
Electron Configs from Periodic Table
When trying to determine electron configuration from looking at the periodic table, why is it that we write out the d orbital with (n-1) when we look to the period number (n) to determine the configuration? For example for silver which is [Kr](4d^10)(5s^1), what in the table indicates that we should...
- Mon Oct 22, 2018 9:08 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Series and Wavelengths part 2
- Replies: 1
- Views: 173
Series and Wavelengths part 2
In another question 1.57, it gives lines in the Balmer series of the hydrogen spectrum (656.3, 486.1, 434.0, and 410.2 nm) and asks for the next wavelength. In the solutions manual is shows that we must solve for energy using n(1) = 2 and n(2) = 7. How come we use n(2) = 7 when it states that its in...
- Mon Oct 22, 2018 9:07 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Series and Wavelengths
- Replies: 4
- Views: 402
Re: Series and Wavelengths
In another question 1.57, it gives lines in the Balmer series of the hydrogen spectrum (656.3, 486.1, 434.0, and 410.2 nm) and asks for the next wavelength. In the solutions manual is shows that we must solve for energy using n(1) = 2 and n(2) = 7. How come we use n(2) = 7 when it states that its in...
- Fri Oct 19, 2018 3:38 pm
- Forum: Properties of Light
- Topic: problem 1.25
- Replies: 2
- Views: 343
Re: problem 1.25
I am looking at the solutions manual now and I believe the equation it recommends is E=hcλ^-1. λ still represents the wavelength that you used in your equation. The ^-1 just means that hc is divided by λ, like how you wrote the equation. I believe frequency is either represented by v or f.
- Fri Oct 19, 2018 3:30 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Series and Wavelengths
- Replies: 4
- Views: 402
Series and Wavelengths
How do series, such as the Lyman series in which n=1 (describing the number of electron shells) relate to wavelength (as seen on figure 1.10 (pg 7) of the 6th ed. of the textbook)? How does n=1 correspond to the wavelengths of ultraviolet radiation and n=2 correspond to the wavelengths of visible li...
- Fri Oct 12, 2018 12:04 pm
- Forum: Photoelectric Effect
- Topic: Equations
- Replies: 3
- Views: 171
Re: Equations
I think this equation only applies to the kinetic energy of the electrons that are emitted. I don't think this equation would work with photons because photons do not have mass. The energy of a photon comes from its frequency, E=hv, which is only kinetic energy because light is not stationary.
- Fri Oct 12, 2018 11:43 am
- Forum: Properties of Light
- Topic: Oscillation of the Electric and Magnetic Field
- Replies: 1
- Views: 84
Oscillation of the Electric and Magnetic Field
How does the oscillation of the electric and magnetic fields relate to the properties of light? Does the oscillation determine the energy of light/photons? Does light only relate to the electromagnetic spectrum?
- Wed Oct 10, 2018 1:05 am
- Forum: Empirical & Molecular Formulas
- Topic: Writing formulas from mass compositions
- Replies: 1
- Views: 250
Writing formulas from mass compositions
How do you know which order to write chemical formulas? For example, in homework question F 15, where we are asked to find the empirical formula from mass compositions, how do we determine to write the formula as C16H13ClN2O as opposed to C16H13N2ClO? Or as KClO3 instead of ClKO3 in question F 11(b)...
- Fri Oct 05, 2018 12:07 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Molar Mass units
- Replies: 2
- Views: 232
Molar Mass units
When writing out molar masses such as, 1.008 g.mol^-1 H, why is the mole written as to the -1?
- Fri Oct 05, 2018 12:02 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Molar Masses
- Replies: 9
- Views: 603
Re: Molar Masses
Molar masses of elements are listed below the names of the elements on the periodic table and they are often decimals because they describe the average mass of an element with respect to the element's isotopes (varying masses because of the varying numbers of neutrons) and how often those isotopes a...
- Thu Oct 04, 2018 11:53 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Definition and Application of Moles
- Replies: 2
- Views: 417
Definition and Application of Moles
Why is that 1 mol H(2) corresponds to 2 mol H? How does this relate to the "number of things" that moles describe? How is that a mole, number of atoms in exactly 12 g of carbon-12, can be used to describe the "number of things" in other elements, molecules, etc without having to ...