Search found 51 matches

by ranqiao1e
Fri Dec 06, 2019 11:45 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Lewis Acid
Replies: 4
Views: 193

Re: Lewis Acid

Because they can accept an extra pair of electrons.
by ranqiao1e
Fri Dec 06, 2019 11:40 pm
Forum: Naming
Topic: How to find out the oxidation number?
Replies: 3
Views: 74

Re: How to find out the oxidation number?

The oxidation number of the central atom in a coordination compound depends on the oxidation number of the ligand.
by ranqiao1e
Fri Dec 06, 2019 11:37 pm
Forum: Calculating the pH of Salt Solutions
Topic: pH vs. pOH
Replies: 17
Views: 354

Re: pH vs. pOH

Ph measures acidity of the solution, and POh measure how basic the solution is. P stands for the -log of []
by ranqiao1e
Fri Dec 06, 2019 11:09 pm
Forum: Polyprotic Acids & Bases
Topic: Definition of Polyprotic
Replies: 5
Views: 158

Re: Definition of Polyprotic

Poly means many. Polyprotic means lots of protons. Polyprotic acids can donate more than one protons and bases can accept more than one protons.
by ranqiao1e
Fri Dec 06, 2019 11:04 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: what is a ligand?
Replies: 7
Views: 86

Re: what is a ligand?

Ligand is a Lewis base that can donate a pair of electrons. Note that Cl is not a Ligand but the electron-donating CL- is
by ranqiao1e
Fri Nov 29, 2019 9:40 pm
Forum: Hybridization
Topic: Pi vs Sigma Bonds
Replies: 10
Views: 87

Re: Pi vs Sigma Bonds

Because sigma bonds have greater overlap than pi bonds do.
by ranqiao1e
Fri Nov 29, 2019 9:39 pm
Forum: Bond Lengths & Energies
Topic: Melting Points
Replies: 8
Views: 256

Re: Melting Points

Yes you are right. It takes higher energy to break the bonds.
by ranqiao1e
Fri Nov 29, 2019 9:34 pm
Forum: Hybridization
Topic: Sigma and Pi Bonds
Replies: 21
Views: 157

Re: Sigma and Pi Bonds

All single covalent bonds have one and only one sigma bond, while double bonds and triple bonds have multiple pi bonds
by ranqiao1e
Fri Nov 29, 2019 9:28 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent Shape
Replies: 29
Views: 738

Re: Bent Shape

One or two lone pairs
by ranqiao1e
Fri Nov 29, 2019 9:27 pm
Forum: Hybridization
Topic: sigma or pi?
Replies: 20
Views: 281

Re: sigma or pi?

If it’s a single bond, then the bond is sigma. If it’s a double bond, then the bond is pi.
by ranqiao1e
Fri Nov 22, 2019 10:26 pm
Forum: Hybridization
Topic: Pi vs Sigma Bonds
Replies: 10
Views: 87

Re: Pi vs Sigma Bonds

Because the overlapping area of sigma bond is much bigger than pi bonds
by ranqiao1e
Fri Nov 22, 2019 10:24 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw
Replies: 23
Views: 210

Re: Seesaw

Yes it is less because lone pair would require some kind of experiment to determine its actual value
by ranqiao1e
Fri Nov 22, 2019 10:23 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Strength of Repulsion
Replies: 4
Views: 60

Re: Strength of Repulsion

Because they occupy a bigger area than bonds do
by ranqiao1e
Fri Nov 22, 2019 10:21 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Why is CH2Cl2 polar?
Replies: 12
Views: 147

Re: Why is CH2Cl2 polar?

Because the Cl is much more electronegative than carbon
by ranqiao1e
Fri Nov 15, 2019 10:23 pm
Forum: Ionic & Covalent Bonds
Topic: Bond Strength
Replies: 12
Views: 213

Re: Bond Strength

Ionic is stronger than covalent, but ionic in water is weaker than covalent.
by ranqiao1e
Fri Nov 15, 2019 10:21 pm
Forum: DeBroglie Equation
Topic: De Broglie Wavelength
Replies: 23
Views: 1888

Re: De Broglie Wavelength

Most likely the problem is not gonna tell you which equation to use, but you can use de broglie when there’s mass.
by ranqiao1e
Fri Nov 15, 2019 9:48 pm
Forum: Bond Lengths & Energies
Topic: Shorter bond lengths
Replies: 12
Views: 118

Re: Shorter bond lengths

Because they are pulled more closely to each other
by ranqiao1e
Fri Nov 15, 2019 6:36 pm
Forum: Electronegativity
Topic: Ionization Energy vs. Electronegativity
Replies: 9
Views: 203

Re: Ionization Energy vs. Electronegativity

Ionization energy has the same trend as electronegativity on the periodic table.
by ranqiao1e
Fri Nov 08, 2019 10:02 pm
Forum: Trends in The Periodic Table
Topic: atomic radius
Replies: 7
Views: 158

Re: atomic radius

As effective nuclear charge decreases the electrons are held less closely together, so the atomic radius is larger.
by ranqiao1e
Fri Nov 08, 2019 10:00 pm
Forum: Sigma & Pi Bonds
Topic: Single vs. Double bonds
Replies: 15
Views: 220

Re: Single vs. Double bonds

Because the strength of the single bond is much weaker than double bonds, so the electrons are held less closely together.
by ranqiao1e
Fri Nov 08, 2019 9:56 pm
Forum: Octet Exceptions
Topic: Octet Rule exceptions
Replies: 14
Views: 323

Re: Octet Rule exceptions

When making an exception can lower the formal charge or make it a lot more stable.
by ranqiao1e
Fri Nov 08, 2019 6:19 pm
Forum: Electronegativity
Topic: Ionic or covalent?
Replies: 17
Views: 215

Re: Ionic or covalent?

If it is a metal bonding to a nonmetal, it is ionic.
by ranqiao1e
Fri Nov 08, 2019 6:18 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 18
Views: 394

Re: Resonance Structures

They help to stabilize the molecule.
by ranqiao1e
Fri Nov 01, 2019 11:27 am
Forum: Electronegativity
Topic: Electronegativity
Replies: 11
Views: 150

Re: Electronegativity

Electronegativity increases from left to right and from bottom to top across the periodic table.
by ranqiao1e
Fri Nov 01, 2019 11:21 am
Forum: Electronegativity
Topic: electronegative
Replies: 6
Views: 118

Re: electronegative

Then the bond is said to be polar. Since the more electronegative atom hogs more electrons to its side, it has a partial negative charge, while the other atom has a partially positive charge.
by ranqiao1e
Fri Nov 01, 2019 11:12 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Writing electron configuration
Replies: 7
Views: 114

Re: Writing electron configuration

The right way would be to write the 3D sub shell first
by ranqiao1e
Fri Nov 01, 2019 11:10 am
Forum: Electronegativity
Topic: Electronegativity on Test
Replies: 7
Views: 84

Re: Electronegativity on Test

We don’t need to calculate the electronegtivity but we do need to know the electronegativity of atoms relative to each other.
by ranqiao1e
Fri Nov 01, 2019 11:05 am
Forum: Significant Figures
Topic: Sig Figs on Tests
Replies: 24
Views: 1113

Re: Sig Figs on Tests

You should round according to the least number of sig figs in a questions. Remember to keep as many sig fits as possible while doing to problem and round at the final step.
by ranqiao1e
Fri Oct 25, 2019 6:52 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: ml alue (i.e., ...-1,0,1,....)
Replies: 2
Views: 48

ml alue (i.e., ...-1,0,1,....)

How do you determine the ml value from l and n value? What's the rule for it?
by ranqiao1e
Fri Oct 25, 2019 6:45 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Exceptions
Replies: 2
Views: 53

Re: Exceptions

In order to be more stable, some electrons in certain atoms may not follow the rule. Remember that they want to be as "happy" as possible.
by ranqiao1e
Fri Oct 25, 2019 6:43 pm
Forum: DeBroglie Equation
Topic: Help with the concept of De Broglie's
Replies: 8
Views: 516

Re: Help with the concept of De Broglie's

Objects with this small of a wavelength does not have wave-like properties.
by ranqiao1e
Fri Oct 25, 2019 6:39 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Energy of spdf orbitals
Replies: 11
Views: 160

Re: Energy of spdf orbitals

505106414 wrote:Can someone explain what a shell is vs a subshell?


An energy shell is represented by n, while sub shells are spdf.
by ranqiao1e
Fri Oct 25, 2019 6:33 pm
Forum: Trends in The Periodic Table
Topic: Electronegativity
Replies: 3
Views: 41

Re: Electronegativity

The more protons the atom has, the more electronegative it is.
by ranqiao1e
Fri Oct 18, 2019 1:27 pm
Forum: Properties of Electrons
Topic: Delta
Replies: 3
Views: 60

Re: Delta

the change in energy should not be negative when n goes from 1 to 3 because electrons need to absorb energy in order to do that, making the sign in front of delta always a positive one.
by ranqiao1e
Fri Oct 18, 2019 1:25 pm
Forum: Properties of Light
Topic: Where to find equations?
Replies: 5
Views: 71

Re: Where to find equations?

I would recommend just using the equations found on the constant sheet on the website because they are all we have on the test and we can definitely solve all the problems using those equations.
by ranqiao1e
Fri Oct 18, 2019 1:20 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Best Way To Study?
Replies: 56
Views: 1178

Re: Best Way To Study?

I always find it easy to do as many practice problems as I can. Be sure to expose yourself to different kinds of problems. It is always helpful to go to worshops or step-ups.
by ranqiao1e
Fri Oct 18, 2019 1:09 pm
Forum: *Shrodinger Equation
Topic: Schrodinger and De Broglie's Equation
Replies: 3
Views: 62

Re: Schrodinger and De Broglie's Equation

Schrodinger's is used to calculate the energy level of atoms. De Broglie's is used to calculate the wavelength of a moving object.
by ranqiao1e
Fri Oct 18, 2019 1:07 pm
Forum: Significant Figures
Topic: sig figs and periodic tables
Replies: 11
Views: 401

Re: sig figs and periodic tables

You should use the one Professor Lavelle gives us on his website. On the test, I usually keep as many sig figs as I can when I'm doing calculations to keep my answers as precise as possible.
by ranqiao1e
Fri Oct 11, 2019 4:38 pm
Forum: Empirical & Molecular Formulas
Topic: empirical = molecular?
Replies: 15
Views: 545

Re: empirical = molecular?

In this case, the chemical formula is both empirical and molecular.
by ranqiao1e
Fri Oct 11, 2019 4:36 pm
Forum: Properties of Light
Topic: Electric vs Magnetic Fields
Replies: 2
Views: 33

Re: Electric vs Magnetic Fields

I know that magnetic forces result from moving charges and act on moving charges. Whereas electric forces are generated and used on charges. They are very similar and often go hands in hands with each other.
by ranqiao1e
Fri Oct 11, 2019 4:31 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Theoretical vs. Actual Yield
Replies: 38
Views: 3433

Re: Theoretical vs. Actual Yield

E.g., the scale is off, your measurement is not perfectly precise, some of the reactants evaporate during the reaction.
by ranqiao1e
Fri Oct 11, 2019 4:28 pm
Forum: Significant Figures
Topic: Sig Figs in Answer
Replies: 8
Views: 259

Re: Sig Figs in Answer

Usually I would do three, but I think 4 works better for certain questions. I would leave no more than 4.
by ranqiao1e
Fri Oct 11, 2019 4:27 pm
Forum: Limiting Reactant Calculations
Topic: percent yield
Replies: 10
Views: 348

Re: percent yield

We only need to worry about percent yield when the problem asks us to do so. However, while doing experiments, we should always expect a difference between the theoretical and the actual
by ranqiao1e
Thu Oct 03, 2019 4:39 pm
Forum: General Science Questions
Topic: Order of Elements When Writing Out a Compound
Replies: 8
Views: 198

Re: Order of Elements When Writing Out a Compound

Also, I think the order doesn't matter unless the question explicitly asks for it. It's not as strict as the other rules, as long as you can draw the right chemical structure from the formula.
by ranqiao1e
Thu Oct 03, 2019 4:32 pm
Forum: General Science Questions
Topic: Naming compounds
Replies: 6
Views: 114

Re: Naming compounds

We should be familiar with the common polyatomic compounds and the prefixes, but I don't know if we need to have them memorized before our first test.
by ranqiao1e
Thu Oct 03, 2019 4:28 pm
Forum: SI Units, Unit Conversions
Topic: Formula units vs molecule
Replies: 7
Views: 165

Re: Formula units vs molecule

For questions asking for formula units of a molecule, the unit for your answer should be atoms. So I think these questions are asking you to find N (i.e., number of molecules).
by ranqiao1e
Thu Oct 03, 2019 4:21 pm
Forum: Significant Figures
Topic: Sig Figs and Rounding
Replies: 4
Views: 104

Re: Sig Figs and Rounding

I think either way it should be fine. As long as your steps are correct, having your final answer off by .1 should not be a problem.
by ranqiao1e
Wed Oct 02, 2019 5:45 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactant Question
Replies: 4
Views: 43

Re: Limiting Reactant Question

I think the latter one is right because there isn't any shortage of reactants in this case.

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