Search found 31 matches
- Fri Dec 07, 2018 4:07 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability
- Replies: 3
- Views: 764
Re: Polarizability
The ion will have bigger polarizability when it is bigger, has less electronegativity and less positive charge. So I-has larger polarizability.
- Fri Dec 07, 2018 4:02 pm
- Forum: Air Pollution & Acid Rain
- Topic: Acid Rain
- Replies: 3
- Views: 737
Re: Acid Rain
SO2 reacts with water. That’s the biggest impact.
- Fri Dec 07, 2018 12:59 am
- Forum: Dipole Moments
- Topic: partial charge
- Replies: 2
- Views: 576
partial charge
Why in CH4, the H atoms have nagetive partial charge? The electronegativity of C is higher than H.
- Fri Dec 07, 2018 12:53 am
- Forum: Hybridization
- Topic: Hybridizaiton
- Replies: 1
- Views: 279
Hybridizaiton
I know that hybridization lowering the enerey by permitting the formation of more bonds. But why permitting the formation of more bonds can lower the energy?
- Mon Nov 26, 2018 10:58 pm
- Forum: Resonance Structures
- Topic: Delocalization
- Replies: 6
- Views: 1198
Delocalization
Hi, can someone explains the meaning of delocalization?
- Sun Nov 25, 2018 10:34 pm
- Forum: Hybridization
- Topic: sigma vs. pi bonds
- Replies: 4
- Views: 416
Re: sigma vs. pi bonds
For single bonds, they have one sigma bond. For double bonds, they have one sigma bond and one pi bond. For tripe bonds, they have one sigma bond and two pi bonds. You can just remember that one bond is sigma bond and the rest are pi bonds.
- Sun Nov 25, 2018 10:29 pm
- Forum: Lewis Structures
- Topic: Exceptions to the Octet Rule
- Replies: 5
- Views: 545
Re: Exceptions to the Octet Rule
(1) molecules, such as NO, with an odd number of electrons; (2) molecules in which one or more atoms possess more than eight electrons, such as SF6; and (3) molecules such as BCl3, in which one or more atoms possess less than eight electrons.
- Sun Nov 25, 2018 10:18 pm
- Forum: Electronegativity
- Topic: The central atom
- Replies: 3
- Views: 724
The central atom
Hi, I’m wondering that the central atom should depends on the least electronegativity or the least ionization energy. And also, could you explain exact concept of electronegativity and the ionization energy.
Thank you
Thank you
- Mon Nov 19, 2018 11:25 am
- Forum: Administrative Questions and Class Announcements
- Topic: Discussion
- Replies: 3
- Views: 503
Discussion
Hello, I’m wondering that if we still have discussion on Wednesday since the lecture on Wednesday has been cancelled.
Thank you
Thank you
- Sun Nov 18, 2018 10:43 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: Intermolecular Forces
- Replies: 7
- Views: 1427
Re: Intermolecular Forces
Dipole-dipole forces are attractive forces between the positive end of one polar molecule and the negative end of another polar molecule.The London dispersion force is the weakest intermolecular force. The London dispersion force is a temporary attractive force that results when the electrons in two...
- Sun Nov 18, 2018 10:36 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles Between the Same shape
- Replies: 6
- Views: 699
Re: Bond Angles Between the Same shape
Yes, I think the bond angles would be the same since all the shape are identical.
- Sun Nov 18, 2018 10:28 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: lone pairs
- Replies: 11
- Views: 890
Re: lone pairs
The repulsion of the lone pairs will change the angle between atoms which means it will change the shape of molecules
- Sun Nov 11, 2018 9:46 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability Vs. Polarizing Power
- Replies: 3
- Views: 700
Re: Polarizability Vs. Polarizing Power
When atoms or ions are larger, have less electronegativity and less positive charge, they have more polarizability. When they have smaller size, more electronegativity and more positive charge, they have more polarizing power.
- Sun Nov 11, 2018 5:32 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Electronegativity
- Replies: 6
- Views: 700
Re: Electronegativity
The oxygen is more electronegative.
- Sun Nov 11, 2018 5:24 pm
- Forum: Dipole Moments
- Topic: VSPER
- Replies: 8
- Views: 976
Re: VSPER
VSEPR model explains experimenetally observed shape of molecules. Whereas the Lewis Structure just show a 2D representation of molecular shape and indicates approximate location of bonding.
- Sun Nov 11, 2018 5:16 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability Trend
- Replies: 6
- Views: 6516
Re: Polarizability Trend
When the atoms or ions have larger size, less electronegativity, and less positive charge, they have more polarizability.
When the atoms or ions have smaller size, more electronegarivity, and more positive charge, they have more polarizing power.
When the atoms or ions have smaller size, more electronegarivity, and more positive charge, they have more polarizing power.
- Sun Nov 11, 2018 5:07 pm
- Forum: Bond Lengths & Energies
- Topic: 2D 15)
- Replies: 3
- Views: 734
Re: 2D 15)
C-F bond is the strongest bond. Since the smaller the internuclear distance is, the stronger the bond is. According to their radius, the internuclear distance between C-F bond is the smallest, so CF4 has the strongest bond.
- Fri Nov 02, 2018 2:37 am
- Forum: Lewis Structures
- Topic: How to determine central atom
- Replies: 8
- Views: 1503
Re: How to determine central atom
The central atom is the least electronegative one.
- Fri Nov 02, 2018 2:20 am
- Forum: Octet Exceptions
- Topic: octet exceptions
- Replies: 4
- Views: 496
octet exceptions
Is there any reason for the octet exceptions that elements in 13th column don’t have to complete octet?
- Fri Nov 02, 2018 2:05 am
- Forum: Trends in The Periodic Table
- Topic: The exception of ionization energies
- Replies: 1
- Views: 1320
The exception of ionization energies
The first ionization energies generally increase across the period, however, the first ionization energy of oxygen is lower than before, so as the S and Se element. Is there any explanation for this decrease? Should we remember that?
- Fri Nov 02, 2018 1:44 am
- Forum: Electronegativity
- Topic: Electron Configuration
- Replies: 2
- Views: 351
Re: Electron Configuration
Yes, the photo below can give you the sequence of orbits:
- Fri Nov 02, 2018 1:39 am
- Forum: Octet Exceptions
- Topic: The center atom
- Replies: 20
- Views: 3340
The center atom
The Lewis Structure of HClO is that O atom at the center bonded with H and Cl atom. However, the Cl atom is the least electronegative one except hydrogen, so why Cl atom is at the center of HClO’s Lewis Structure?
- Fri Nov 02, 2018 1:12 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Perchlorate (ClO4)-
- Replies: 7
- Views: 12473
Re: Perchlorate (ClO4)-
Since the -1 charge should be on more electronegative atom. And the oxygen atom is more electronegative.
- Fri Nov 02, 2018 12:55 am
- Forum: Resonance Structures
- Topic: Most Stable Configuration
- Replies: 11
- Views: 1208
Re: Most Stable Configuration
When the formal charge(FC)is equal to 0, it is the most stable configuration, the more configuration is close to 0, the more stable the configuration is.
- Fri Nov 02, 2018 12:54 am
- Forum: Resonance Structures
- Topic: Most Stable Configuration
- Replies: 11
- Views: 1208
Re: Most Stable Configuration
When the formal charge(FC)is equal to 0, it is the most stable configuration, the more configuration is close to 0, the more stable the configuration is.
- Thu Nov 01, 2018 10:24 pm
- Forum: Lewis Structures
- Topic: Valence Electrons
- Replies: 3
- Views: 395
Re: Valence Electrons
You can simply figure this out by checking their electric configurations, the number of the electrons in the last s or p orbital would tell you.
- Thu Nov 01, 2018 10:17 pm
- Forum: Lewis Structures
- Topic: central atoms
- Replies: 8
- Views: 793
Re: central atoms
It should be the least electronegative atom, except Hydrogen.
- Thu Nov 01, 2018 9:09 pm
- Forum: Lewis Structures
- Topic: HClO3
- Replies: 2
- Views: 793
Re: HClO3
If you the Cl bonded to the H, there would be only 24 valence electrons
- Wed Oct 10, 2018 12:39 am
- Forum: Molarity, Solutions, Dilutions
- Topic: Why amount of CH3CO2- doubled for each Ca(CH3CO2)2
- Replies: 4
- Views: 1095
Re: Why amount of CH3CO2- doubled for each Ca(CH3CO2)2
Since each Ca2+ combine with 2 (CH3CO2)-
- Wed Oct 10, 2018 12:30 am
- Forum: Empirical & Molecular Formulas
- Topic: F.7
- Replies: 5
- Views: 1725
Re: F.7
Suppose that the mass of O atoms is 16g, according to the question, the percentage of O atoms is(100%-88.8%)=11.2%. Therefore, the molar mass of M2O would be 142.8g*mol^-1. So the molar mass of M is 63.4g*mol^-1, M is copper.
- Wed Oct 10, 2018 12:08 am
- Forum: Significant Figures
- Topic: Sig Fig zero rules
- Replies: 7
- Views: 2369
Re: Sig Fig zero rules
All non-zero digits are significant
Zeros between non-zero digits are significant
Leading zeros are never significant
In a number with a decimal point, trailing zeros (those to the right of the last non-zero digit) are significant
Zeros between non-zero digits are significant
Leading zeros are never significant
In a number with a decimal point, trailing zeros (those to the right of the last non-zero digit) are significant