Search found 30 matches

by Susu Le 1F
Sat Jun 09, 2018 3:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: ICl2- Shape
Replies: 2
Views: 6875

Re: ICl2- Shape

There are a total of 5 regions of electron density. Therefore, they are arranged in a trigonal bipyramidal way. The three lone pairs are in one plane in the shape of a triangle around the central atom (can be thought of the x,y plane) while the 3 atoms (Cl-I-Cl) are in a straight line in the z plane...
by Susu Le 1F
Sat Jun 09, 2018 2:50 pm
Forum: Conjugate Acids & Bases
Topic: Difference between Lewis and conjugate acids and bases
Replies: 4
Views: 365

Re: Difference between Lewis and conjugate acids and bases

A Lewis acid has a conjugate base in the products of the reaction, and a Lewis base has a conjugate acid in the products of the reaction. For example, look at the reaction NH3 + H2O —> NH4+ + OH-. NH3 is the Lewis Base because it can donate its lone pair of electrons, and its conjugate acid is NH4+....
by Susu Le 1F
Sat Jun 09, 2018 2:59 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Determining Exact Bond Angle [ENDORSED]
Replies: 2
Views: 106

Re: Determining Exact Bond Angle [ENDORSED]

I’m pretty sure that it is enough to know that the bond angle is less than 120.
by Susu Le 1F
Sun Jun 03, 2018 1:07 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: "-dral" Vs "-dron"
Replies: 2
Views: 89

Re: "-dral" Vs "-dron"

I think that -dral is the adjective form of -dron. For example, you can say “a molecule has an octahedral shape” or “the shape is an octahedron”. Octahedral is an adjective while octahedron is a noun.
by Susu Le 1F
Sun Jun 03, 2018 1:03 pm
Forum: Biological Examples
Topic: chemotherapy example [ENDORSED]
Replies: 4
Views: 270

Re: chemotherapy example [ENDORSED]

I thought that for the cisplatin chemotherapy drug, when the drug is near the DNA, the 2 Chlorine atoms that are on the same side will break off from the central Pt atom. They will be replaced with 2 Nitrogen atoms found on the DNA strand. Therefore, the cisplatin is now bonded to the DNA at 2 diffe...
by Susu Le 1F
Sun Jun 03, 2018 12:55 pm
Forum: Lewis Structures
Topic: Test Q.8 [ENDORSED]
Replies: 7
Views: 276

Re: Test Q.8 [ENDORSED]

For the bond that is x-ed out, the double bond can be moved. Therefore, resonance occurs for that structure and the actual structure consists of 4 bonds that are a blend of a single bond and a double bond. Therefore, the length of these 4 bonds are longer than the length of a double bond.
by Susu Le 1F
Wed May 23, 2018 11:46 am
Forum: Ionic & Covalent Bonds
Topic: Polyatomic Ions
Replies: 1
Views: 84

Re: Polyatomic Ions

The atoms within each polyatomic ion are linked by the sharing of electrons (covalent bonds). However the polyatomic ions are linked together due to their (+) and (-) charge, which resulted from the transfer of an electron. Therefore, one polyatomic ion is negative while the other polyatomic ion is ...
by Susu Le 1F
Wed May 23, 2018 11:20 am
Forum: Resonance Structures
Topic: Ionic character
Replies: 3
Views: 293

Re: Ionic character

Covalent bonds that have an increasing difference in electronegativity have increasing ionic character. Therefore, a larger radius means decreasing electronegativity, which means less difference in electronegativity between the 2 atoms, which means less ionic character.
by Susu Le 1F
Wed May 23, 2018 11:07 am
Forum: Octet Exceptions
Topic: Octet Rule Exceptions
Replies: 1
Views: 158

Re: Octet Rule Exceptions

Elements that are in Period 3 and below may have exceptions to the octet rule because they can have more electrons in their d orbital if their s and p orbitals are full with 8 electrons. Some common examples are Sulfur and Xenon. Some elements only have 6 valence electrons after bonding such as Boro...
by Susu Le 1F
Sat May 19, 2018 10:02 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: Dipole-Induced Dipole Interactions in Solution [ENDORSED]
Replies: 1
Views: 246

Re: Dipole-Induced Dipole Interactions in Solution [ENDORSED]

If HCl dissociated into H+ and Cl-, they would be considered ions now and I think they would be able to form ion to induced dipole interactions with N2 because dispersion attractive forces can occur between any atom/molecule.
by Susu Le 1F
Fri May 18, 2018 7:36 pm
Forum: Dipole Moments
Topic: Dipole relevance
Replies: 4
Views: 135

Re: Dipole relevance

A dipole is a molecule that has a slightly positive and a slightly negative region. Water is considered to be a dipole because the oxygen is the slightly negative region while the hydrogens cause the other side of the water molecule to be slightly positive.
by Susu Le 1F
Fri May 18, 2018 6:03 pm
Forum: Bond Lengths & Energies
Topic: Pentane vs. 2,2 Dimethylpropane
Replies: 3
Views: 295

Re: Pentane vs. 2,2 Dimethylpropane

I think by tightly packed he meant that the atoms in the molecule are more tightly packed, which means the atoms are closer together. So the structure is more tightly packed, and not the molecules are packed together. Therefore, pentane is less tightly packed because it’s atoms are in a straight line.
by Susu Le 1F
Wed May 09, 2018 6:50 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Order of Orbitals
Replies: 3
Views: 168

Re: Order of Orbitals

When going across a period on the periodic table, the s orbital fills up first but if there are d-orbital electrons, the d-orbital will end up being at a lower energy level so in the electron configuration, you put the d-orbital electrons before the s-orbital electrons. For example, the electron con...
by Susu Le 1F
Wed May 09, 2018 6:37 am
Forum: Photoelectric Effect
Topic: Work function and kinetic energy
Replies: 1
Views: 132

Re: Work function and kinetic energy

The work function of A is less than the work function of B, which means that it takes LESS energy to remove an electron from A. This also means that if the same light is shown on both, there is more excess energy that goes into the kinetic energy of the emitted electron from A than B. So, the electr...
by Susu Le 1F
Wed May 09, 2018 6:31 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: equation
Replies: 2
Views: 134

Re: equation

The h with the line through it (ħ) in the answer key equals h/2π (this h is Planck’s constant). If you replace the ħ in ∆p*∆x=1/2*ħ with h/2π, then you get ∆p*∆x=h/4π, which is the Heisenberg Uncertainty equation given in class. For 1.43, you would use this equation to find ∆p and then use ∆p=m∆v to...
by Susu Le 1F
Sun May 06, 2018 9:46 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic Bond formation
Replies: 5
Views: 186

Re: Ionic Bond formation

That energy is required to overcome the effective nuclear charge that is acting on the electron.
by Susu Le 1F
Sun May 06, 2018 8:36 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Ions in terms of molar mass
Replies: 2
Views: 154

Re: Ions in terms of molar mass

An ion is created when a neutral atom gains or loses electron(s). However, I think that the gain or loss of mass due to electrons is too small to be significant. Therefore, just use what it says on the periodic table for the molar mass.
by Susu Le 1F
Sun May 06, 2018 3:33 am
Forum: Photoelectric Effect
Topic: 1.34
Replies: 2
Views: 182

Re: 1.34

Energy of the photon of radiation=work function+kinetic energy of the electron 1) Convert 4.37 eV to J using 1 eV=1.602x10-19 J. This is the work function. 2) Find the kinetic energy of the electron by using Ek=1/2*m*v^2. 3) Add the work function and the Ek(kinetic energy) together to get the energy...
by Susu Le 1F
Thu Apr 26, 2018 11:08 pm
Forum: Quantum Numbers and The H-Atom
Topic: Fourth Quantum Number
Replies: 5
Views: 178

Re: Fourth Quantum Number

I am confused on how we would determine if an electron is spinning up or down?
by Susu Le 1F
Thu Apr 26, 2018 10:53 pm
Forum: Quantum Numbers and The H-Atom
Topic: higher energy/ lower energy
Replies: 2
Views: 116

Re: higher energy/ lower energy

I think it also has to do with electron shielding like how electrons in the s orbital experience the least shielding within an energy level and electrons in the f orbital experience the most electron shielding within the same energy level. Due to this, the s electrons are more attracted and closer t...
by Susu Le 1F
Thu Apr 26, 2018 10:30 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 2.1 help [ENDORSED]
Replies: 3
Views: 127

Re: 2.1 help [ENDORSED]

They all increase because for the 1s orbital: n=1 and l=0, and for the 2p orbital: n=2 and l=1. Therefore, both n and l increase. Also, the energy of the electron increased because the electron jumped to a higher energy level. The radius of the atom also increases because the 2p orbital is further f...
by Susu Le 1F
Sat Apr 21, 2018 10:31 pm
Forum: Photoelectric Effect
Topic: Work function [ENDORSED]
Replies: 6
Views: 345

Re: Work function [ENDORSED]

The work function is used in the photoelectric effect problems. And just to clarify, the kinetic energy that is mentioned in the above answer is the kinetic energy of the electron that is emitted. Therefore, the energy of the photon (Ep) - the work function = the kinetic energy of the electron (Ek).
by Susu Le 1F
Sat Apr 21, 2018 10:27 pm
Forum: Properties of Light
Topic: HW Question 1.57
Replies: 3
Views: 108

Re: HW Question 1.57

Since the question states that it’s the Balmer series, the electron is dropping from a higher energy level to the energy level of n=2. The greater the wavelength, the smaller the energy, so: 656.3 nm corresponds the the smallest transition, which is from n=3 to n=2. 486.1 nm corresponds to n=4 to n=...
by Susu Le 1F
Sat Apr 21, 2018 10:02 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect Post Module [ENDORSED]
Replies: 2
Views: 110

Re: Photoelectric Effect Post Module [ENDORSED]

B) The amount of energy required to remove an electron from one sodium atom is equal to the work function of sodium that is given in the question. Therefore, just convert the 150.6 kJ to J, and you would result in 1.506 x 10^5 J. C) The energy of the photon of light that is hitting the sodium surfac...
by Susu Le 1F
Wed Apr 11, 2018 5:41 pm
Forum: Empirical & Molecular Formulas
Topic: Molecular to Empirical [ENDORSED]
Replies: 12
Views: 470

Re: Molecular to Empirical [ENDORSED]

You should divide the number of atoms for each element in the molecular formula by the greatest number that would still leave you with whole numbers. For example the molecular formula for glucose is C6H12O6. Dividing this by 6 would still give you whole numbers: CH2O. This is the empirical formula f...
by Susu Le 1F
Wed Apr 11, 2018 5:29 pm
Forum: Molarity, Solutions, Dilutions
Topic: Variables
Replies: 5
Views: 190

Re: Variables

In lecture, he said that we will use Kelvin for calculations such as in gas laws.
by Susu Le 1F
Wed Apr 11, 2018 5:25 pm
Forum: SI Units, Unit Conversions
Topic: Sig Figs
Replies: 9
Views: 387

Re: Sig Figs

We should use the numbers given on the periodic table so that we can get a more accurate answer.
by Susu Le 1F
Sun Apr 08, 2018 6:17 pm
Forum: SI Units, Unit Conversions
Topic: Problem E.9 in textbook
Replies: 3
Views: 179

Re: Problem E.9 in textbook

Using the molar mass of magnesium sulfate heptahydrate (246.48 g/mol) above, you can find the number of moles in 5.15 g of Epsom salts. Once you have the number of moles of Epsom, you can find the number of moles of Oxygen. Finally, you can calculate the number of atoms of oxygen using Avogadro's nu...
by Susu Le 1F
Sun Apr 08, 2018 6:08 pm
Forum: SI Units, Unit Conversions
Topic: Sig figures
Replies: 9
Views: 323

Re: Sig figures

The number of sig figs in your answer should be the least number of sig figs that is given in the question.
by Susu Le 1F
Fri Apr 06, 2018 11:18 pm
Forum: Molarity, Solutions, Dilutions
Topic: Review Worksheet [ENDORSED]
Replies: 3
Views: 155

Re: Review Worksheet [ENDORSED]

1) Multiply 12% by 750 mL of wine. This is the volume of ethanol (mL).
2) Use the volume of ethanol (mL) to find the mass of ethanol (g) by using the density (.789 g/mL). Now you have the mass (g).
3) Divide the mass by the molar mass of ethanol (46.06 g/mol) to find the moles of ethanol.

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