Search found 31 matches

by Kristy 1F
Fri Dec 07, 2018 4:07 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability
Replies: 3
Views: 242

Re: Polarizability

The ion will have bigger polarizability when it is bigger, has less electronegativity and less positive charge. So I-has larger polarizability.
by Kristy 1F
Fri Dec 07, 2018 4:02 pm
Forum: Air Pollution & Acid Rain
Topic: Acid Rain
Replies: 3
Views: 233

Re: Acid Rain

SO2 reacts with water. That’s the biggest impact.
by Kristy 1F
Fri Dec 07, 2018 12:59 am
Forum: Dipole Moments
Topic: partial charge
Replies: 2
Views: 224

partial charge

Why in CH4, the H atoms have nagetive partial charge? The electronegativity of C is higher than H.
by Kristy 1F
Fri Dec 07, 2018 12:53 am
Forum: Hybridization
Topic: Hybridizaiton
Replies: 1
Views: 79

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?
by Kristy 1F
Mon Nov 26, 2018 10:58 pm
Forum: Resonance Structures
Topic: Delocalization
Replies: 5
Views: 479

Delocalization

Hi, can someone explains the meaning of delocalization?
by Kristy 1F
Sun Nov 25, 2018 10:34 pm
Forum: Hybridization
Topic: sigma vs. pi bonds
Replies: 4
Views: 71

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.
by Kristy 1F
Sun Nov 25, 2018 10:29 pm
Forum: Lewis Structures
Topic: Exceptions to the Octet Rule
Replies: 5
Views: 111

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.
by Kristy 1F
Sun Nov 25, 2018 10:18 pm
Forum: Electronegativity
Topic: The central atom
Replies: 3
Views: 234

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
by Kristy 1F
Mon Nov 19, 2018 11:25 am
Forum: Administrative Questions and Class Announcements
Topic: Discussion
Replies: 3
Views: 137

Discussion

Hello, I’m wondering that if we still have discussion on Wednesday since the lecture on Wednesday has been cancelled.
Thank you
by Kristy 1F
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: 183

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...
by Kristy 1F
Sun Nov 18, 2018 10:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles Between the Same shape
Replies: 6
Views: 91

Re: Bond Angles Between the Same shape

Yes, I think the bond angles would be the same since all the shape are identical.
by Kristy 1F
Sun Nov 18, 2018 10:28 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: lone pairs
Replies: 11
Views: 165

Re: lone pairs

The repulsion of the lone pairs will change the angle between atoms which means it will change the shape of molecules
by Kristy 1F
Sun Nov 11, 2018 9:46 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability Vs. Polarizing Power
Replies: 3
Views: 140

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.
by Kristy 1F
Sun Nov 11, 2018 5:32 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Electronegativity
Replies: 6
Views: 117

Re: Electronegativity

The oxygen is more electronegative.
by Kristy 1F
Sun Nov 11, 2018 5:24 pm
Forum: Dipole Moments
Topic: VSPER
Replies: 8
Views: 150

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.
by Kristy 1F
Sun Nov 11, 2018 5:16 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability Trend
Replies: 6
Views: 336

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.
by Kristy 1F
Sun Nov 11, 2018 5:07 pm
Forum: Bond Lengths & Energies
Topic: 2D 15)
Replies: 3
Views: 101

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.
by Kristy 1F
Fri Nov 02, 2018 2:37 am
Forum: Lewis Structures
Topic: How to determine central atom
Replies: 8
Views: 166

Re: How to determine central atom

The central atom is the least electronegative one.
by Kristy 1F
Fri Nov 02, 2018 2:20 am
Forum: Octet Exceptions
Topic: octet exceptions
Replies: 4
Views: 121

octet exceptions

Is there any reason for the octet exceptions that elements in 13th column don’t have to complete octet?
by Kristy 1F
Fri Nov 02, 2018 2:05 am
Forum: Trends in The Periodic Table
Topic: The exception of ionization energies
Replies: 1
Views: 358

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?
by Kristy 1F
Fri Nov 02, 2018 1:44 am
Forum: Electronegativity
Topic: Electron Configuration
Replies: 2
Views: 52

Re: Electron Configuration

Yes, the photo below can give you the sequence of orbits:
D57A7536-EF5B-4125-A702-BAE62B5C0FDA.png
by Kristy 1F
Fri Nov 02, 2018 1:39 am
Forum: Octet Exceptions
Topic: The center atom
Replies: 20
Views: 599

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?
by Kristy 1F
Fri Nov 02, 2018 1:12 am
Forum: Formal Charge and Oxidation Numbers
Topic: Perchlorate (ClO4)-
Replies: 7
Views: 1462

Re: Perchlorate (ClO4)-

Since the -1 charge should be on more electronegative atom. And the oxygen atom is more electronegative.
by Kristy 1F
Fri Nov 02, 2018 12:55 am
Forum: Resonance Structures
Topic: Most Stable Configuration
Replies: 11
Views: 216

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.
by Kristy 1F
Fri Nov 02, 2018 12:54 am
Forum: Resonance Structures
Topic: Most Stable Configuration
Replies: 11
Views: 216

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.
by Kristy 1F
Thu Nov 01, 2018 10:24 pm
Forum: Lewis Structures
Topic: Valence Electrons
Replies: 3
Views: 110

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.
by Kristy 1F
Thu Nov 01, 2018 10:17 pm
Forum: Lewis Structures
Topic: central atoms
Replies: 8
Views: 164

Re: central atoms

It should be the least electronegative atom, except Hydrogen.
by Kristy 1F
Thu Nov 01, 2018 9:09 pm
Forum: Lewis Structures
Topic: HClO3
Replies: 2
Views: 88

Re: HClO3

If you the Cl bonded to the H, there would be only 24 valence electrons
by Kristy 1F
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: 594

Re: Why amount of CH3CO2- doubled for each Ca(CH3CO2)2

Since each Ca2+ combine with 2 (CH3CO2)-
by Kristy 1F
Wed Oct 10, 2018 12:30 am
Forum: Empirical & Molecular Formulas
Topic: F.7
Replies: 5
Views: 343

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.
by Kristy 1F
Wed Oct 10, 2018 12:08 am
Forum: Significant Figures
Topic: Sig Fig zero rules
Replies: 7
Views: 238

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

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