Search found 39 matches

by Sara Sadrolsadat 1G
Sat Dec 08, 2018 2:52 pm
Forum: Amphoteric Compounds
Topic: How is NH in thymine amphiprotic?
Replies: 1
Views: 215

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?
by Sara Sadrolsadat 1G
Sat Dec 08, 2018 2:35 pm
Forum: Lewis Acids & Bases
Topic: Boric acid acidity
Replies: 1
Views: 49

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...
by Sara Sadrolsadat 1G
Sat Dec 08, 2018 2:32 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted base, Lewis acid
Replies: 2
Views: 63

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?
by Sara Sadrolsadat 1G
Sat Dec 08, 2018 2:31 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted base, Lewis acid
Replies: 1
Views: 51

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?
by Sara Sadrolsadat 1G
Sat Dec 08, 2018 2:24 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Electron donating properties of CH3 [ENDORSED]
Replies: 1
Views: 216

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...
by Sara Sadrolsadat 1G
Sat Dec 08, 2018 11:33 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Tetrahedral and Square Planar Complexes
Replies: 1
Views: 42

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?
by Sara Sadrolsadat 1G
Fri Dec 07, 2018 1:02 am
Forum: Bronsted Acids & Bases
Topic: Exceptions: HSO4- and H2PO4-
Replies: 4
Views: 84

Exceptions: HSO4- and H2PO4-

Why is it that HSO4- and H2PO4- act as acids unlike other anions? Is it more favorable somehow?
by Sara Sadrolsadat 1G
Sun Dec 02, 2018 5:32 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: French Toast 28
Replies: 3
Views: 223

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).
by Sara Sadrolsadat 1G
Sun Dec 02, 2018 5:25 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Strong acids
Replies: 2
Views: 66

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...
by Sara Sadrolsadat 1G
Sun Dec 02, 2018 5:16 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Definition of Ligand
Replies: 2
Views: 56

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...
by Sara Sadrolsadat 1G
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: 243

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?
by Sara Sadrolsadat 1G
Tue Nov 27, 2018 2:13 pm
Forum: Hybridization
Topic: Hybrid Orbitals
Replies: 3
Views: 316

Hybrid Orbitals

Do all atoms have hybrid orbitals within a molecule?
by Sara Sadrolsadat 1G
Tue Nov 27, 2018 2:08 pm
Forum: Hybridization
Topic: Lone Electrons and Hybridization
Replies: 3
Views: 89

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.
by Sara Sadrolsadat 1G
Sat Nov 24, 2018 6:31 pm
Forum: Hybridization
Topic: B3N3H6 Lewis Structure and Hybridization (6th ed. 4.81)
Replies: 1
Views: 52

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 ...
by Sara Sadrolsadat 1G
Sat Nov 24, 2018 6:24 pm
Forum: Dipole Moments
Topic: *Hydrogen Bonding
Replies: 2
Views: 97

*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...
by Sara Sadrolsadat 1G
Sat Nov 24, 2018 6:21 pm
Forum: Hybridization
Topic: Hybrid Orbitals and Sigma/Pi Bonds
Replies: 1
Views: 58

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?
by Sara Sadrolsadat 1G
Sun Nov 18, 2018 9:01 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Resonance Structures and bond angles
Replies: 4
Views: 188

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?
by Sara Sadrolsadat 1G
Sun Nov 18, 2018 8:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Angles Less Than a Certain Value
Replies: 4
Views: 98

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...
by Sara Sadrolsadat 1G
Sun Nov 18, 2018 8:45 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape Patterns
Replies: 5
Views: 99

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?
by Sara Sadrolsadat 1G
Thu Nov 08, 2018 8:24 pm
Forum: Bond Lengths & Energies
Topic: Bond Lengths with Larger Atoms
Replies: 1
Views: 67

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?
by Sara Sadrolsadat 1G
Thu Nov 08, 2018 8:15 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability vs. Polarizing Power
Replies: 2
Views: 77

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)
by Sara Sadrolsadat 1G
Thu Nov 08, 2018 8:10 pm
Forum: Dipole Moments
Topic: Dipole vs. Hydrogen Bonds
Replies: 2
Views: 60

Dipole vs. Hydrogen Bonds

How are dipole interactions weaker than hydrogen bonds, even though dipole interactions involve polar molecules?
by Sara Sadrolsadat 1G
Sun Nov 04, 2018 4:01 pm
Forum: Administrative Questions and Class Announcements
Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
Replies: 121
Views: 5266

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?
by Sara Sadrolsadat 1G
Thu Nov 01, 2018 10:23 pm
Forum: Octet Exceptions
Topic: Odd Lewis Structures
Replies: 3
Views: 104

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...
by Sara Sadrolsadat 1G
Thu Nov 01, 2018 9:42 pm
Forum: Lewis Structures
Topic: Lewis Structures (w/ same formal charge but different bonds)
Replies: 2
Views: 60

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...
by Sara Sadrolsadat 1G
Thu Nov 01, 2018 9:23 pm
Forum: Octet Exceptions
Topic: ClO2 Radical
Replies: 1
Views: 51

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?
by Sara Sadrolsadat 1G
Sun Oct 28, 2018 1:44 pm
Forum: Quantum Numbers and The H-Atom
Topic: Magnetic Spin Number
Replies: 5
Views: 128

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.
by Sara Sadrolsadat 1G
Sun Oct 28, 2018 1:30 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration for Tungsten
Replies: 1
Views: 31

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?
by Sara Sadrolsadat 1G
Sun Oct 28, 2018 1:20 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configs from Periodic Table
Replies: 1
Views: 31

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...
by Sara Sadrolsadat 1G
Mon Oct 22, 2018 9:08 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Series and Wavelengths part 2
Replies: 1
Views: 51

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...
by Sara Sadrolsadat 1G
Mon Oct 22, 2018 9:07 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Series and Wavelengths
Replies: 4
Views: 82

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...
by Sara Sadrolsadat 1G
Fri Oct 19, 2018 3:38 pm
Forum: Properties of Light
Topic: problem 1.25
Replies: 2
Views: 97

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.
by Sara Sadrolsadat 1G
Fri Oct 19, 2018 3:30 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Series and Wavelengths
Replies: 4
Views: 82

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...
by Sara Sadrolsadat 1G
Fri Oct 12, 2018 12:04 pm
Forum: Photoelectric Effect
Topic: Equations
Replies: 3
Views: 52

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.
by Sara Sadrolsadat 1G
Fri Oct 12, 2018 11:43 am
Forum: Properties of Light
Topic: Oscillation of the Electric and Magnetic Field
Replies: 1
Views: 31

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?
by Sara Sadrolsadat 1G
Wed Oct 10, 2018 1:05 am
Forum: Empirical & Molecular Formulas
Topic: Writing formulas from mass compositions
Replies: 1
Views: 119

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)...
by Sara Sadrolsadat 1G
Fri Oct 05, 2018 12:07 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Molar Mass units
Replies: 2
Views: 58

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?
by Sara Sadrolsadat 1G
Fri Oct 05, 2018 12:02 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Molar Masses
Replies: 9
Views: 183

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...
by Sara Sadrolsadat 1G
Thu Oct 04, 2018 11:53 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Definition and Application of Moles
Replies: 2
Views: 56

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 ...

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