Search found 30 matches

by 305127455
Fri Dec 07, 2018 10:01 pm
Forum: Air Pollution & Acid Rain
Topic: Acid Rain
Replies: 9
Views: 426

Re: Acid Rain

Mainly caused by chemicals like SO4^2- and NO3- coming from burning fossil fuels, such as coal.
by 305127455
Fri Dec 07, 2018 9:56 pm
Forum: Biological Examples
Topic: Ligands
Replies: 3
Views: 41

Re: Ligands

Magnesium ligands are in chlorophyll and critical for electron transport chain there.
by 305127455
Fri Dec 07, 2018 9:51 pm
Forum: DeBroglie Equation
Topic: De Brogile Application
Replies: 4
Views: 50

Re: De Brogile Application

Technically De Brogile equation can be used on anything with rest mass; however, the equation is not so helpful on macro objects since their wave property is not obvious.
by 305127455
Fri Dec 07, 2018 9:44 pm
Forum: Ionic & Covalent Bonds
Topic: Boiling point
Replies: 5
Views: 49

Re: Boiling point

Melting and boiling point depend on intermolecular forces. NH3 is polar with its two lone-pair electrons when CH4 is not. As a result, intermolecular forces between NH3 molecules are stronger.
by 305127455
Fri Dec 07, 2018 9:39 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: How to tell which ligands can be polydentrate
Replies: 2
Views: 25

Re: How to tell which ligands can be polydentrate

The angle between two ligands need to be around 90˚.
by 305127455
Fri Dec 07, 2018 9:35 pm
Forum: Electronegativity
Topic: Electronegativity
Replies: 5
Views: 29

Re: Electronegativity

Nitrogen is more electro negative since it has more protons than carbon does.
by 305127455
Fri Dec 07, 2018 9:25 pm
Forum: Conjugate Acids & Bases
Topic: Determining Conjugate Acid
Replies: 5
Views: 56

Re: Determining Conjugate Acid

We just add an H+, and for determining the conjugate base, just subtract an H+.
by 305127455
Fri Dec 07, 2018 9:20 pm
Forum: Bronsted Acids & Bases
Topic: Lewis Acids and Bases and Bronsted?
Replies: 5
Views: 31

Re: Lewis Acids and Bases and Bronsted?

Lewis acid has space for insertion of lone-pair electrons, like AlCl3 in which the Al has 6 bonded electrons and, thus, space for 2 more electrons. Lewis base has lone-pair electrons on the central atom. Brønsted acid donates H+ while Brønsted base accept H+.
by 305127455
Fri Dec 07, 2018 9:14 pm
Forum: Bronsted Acids & Bases
Topic: acidity
Replies: 4
Views: 29

Re: acidity

Longer bonds are weaker, and, thus, easy to break. This means it is easier for H+ to be released, so acids with longer bonds on hydrogen are typically more acidic.
by 305127455
Thu Dec 06, 2018 8:31 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Focus 9C.3 Part d
Replies: 3
Views: 30

Re: Focus 9C.3 Part d

Water is "aqua", which starts with "A."
by 305127455
Thu Dec 06, 2018 8:29 pm
Forum: Conjugate Acids & Bases
Topic: Neutralization Reactions
Replies: 6
Views: 45

Re: Neutralization Reactions

Taking H2O as another product of the reaction and filling the reactants should work.
by 305127455
Thu Dec 06, 2018 8:20 pm
Forum: Conjugate Acids & Bases
Topic: Conjugate Bases
Replies: 7
Views: 53

Re: Conjugate Bases

Conjugate acids and bases exist in pairs, typically one on the left of the equation, and the other on the right of the equation. For example, in the equation H2SO4 + H2O → HSO4- + H3O+, H2SO4 donates an H+ and becomes HSO4-. In this case, We say H2SO4, relative to HSO4-, is conjugate acid since it d...
by 305127455
Wed Dec 05, 2018 9:32 pm
Forum: Naming
Topic: 7th edition 9.C1
Replies: 2
Views: 25

Re: 7th edition 9.C1

If the complex has a total negative charge, add -ate at the end of the metal name. If the complex has a negative charge while the metal name comes from Latin, use the Latin stem.

For example:
Fe: -ferrate
by 305127455
Wed Dec 05, 2018 9:26 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 4
Views: 37

Re: Ligands

We can know it by looking at the valence shell of the central metal and the total charge of ligands. However, there should be more information most of the time.
by 305127455
Wed Dec 05, 2018 9:21 pm
Forum: Naming
Topic: Water as a ligand
Replies: 5
Views: 64

Re: Water as a ligand

Writing in OH2 instead of H2O illustrates that it is the oxygen actually binding to the metal, so we should write OH2.
by 305127455
Tue Dec 04, 2018 8:35 pm
Forum: Calculating the pH of Salt Solutions
Topic: Salt + Water?
Replies: 2
Views: 226

Re: Salt + Water?

In the scope of 14A, yes I think.
by 305127455
Tue Dec 04, 2018 8:32 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: strong or weak base
Replies: 3
Views: 35

Re: strong or weak base

There are 8 common strong bases worth committing to memory. It consists of Alkali and Alkaline Earth metals paired with Hydroxide Ions. LiOH - lithium hydroxide NaOH - sodium hydroxide KOH - potassium hydroxide RbOH - rubidium hydroxide CsOH - cesium hydroxide Ca(OH)2 - calcium hydroxide Sr(OH)2 - ...
by 305127455
Tue Dec 04, 2018 8:29 pm
Forum: Calculating the pH of Salt Solutions
Topic: pH formula?
Replies: 7
Views: 48

Re: pH formula?

I don't think we need to know how to derive it since pH is just an invented representation of proton concentration. For acid it's (-log[H+]), for base it's 14 - (-log[OH-])
by 305127455
Sun Dec 02, 2018 8:13 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: How to determine shape of coordination compound
Replies: 3
Views: 29

Re: How to determine shape of coordination compound

Looking at the formula and calculating bonds and valence electrons should do.
by 305127455
Sun Dec 02, 2018 8:09 pm
Forum: Hybridization
Topic: lone pairs
Replies: 20
Views: 94

Re: lone pairs

Long pairs does count, and memorizing this and "formula" of hybridization should be enough to solve most of the related problems.
by 305127455
Sun Dec 02, 2018 8:04 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodal planes
Replies: 6
Views: 65

Re: Nodal planes

I don' t think we need to remember that. Perhaps the question will give us a diagram and let us tell.
by 305127455
Sun Nov 25, 2018 7:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Naming the Shape
Replies: 16
Views: 113

Re: Naming the Shape

Ruiting Jia 4D wrote:With the shapes, do we need to memorize the bond angles?

I think we only need to remember those basic ones, such as 109.5˚, and how change in structure (like adding lone-pair electrons) can affect them.
by 305127455
Sun Nov 25, 2018 7:38 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shapes Not covered in Lecture
Replies: 10
Views: 75

Re: Shapes Not covered in Lecture

I guess it's better to memorize that since it may be included in questions.
by 305127455
Sun Nov 25, 2018 7:33 pm
Forum: Bond Lengths & Energies
Topic: Drawing resonance structures?
Replies: 6
Views: 60

Re: Drawing resonance structures?

I thinks the question will instruct you if it does want to test your understanding of resonance structure. Otherwise, just leave it.
by 305127455
Sun Nov 18, 2018 7:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pair?
Replies: 4
Views: 58

Re: Lone Pair?

It will require tons of calculation and some mathematic models to determine the exact angles. Also, electrons are not "solid" there since they are actually cloud. This perhaps makes stuff even more difficult.
by 305127455
Sun Nov 18, 2018 7:50 pm
Forum: Student Social/Study Group
Topic: Chemistry News
Replies: 32
Views: 14328

Re: Chemistry News

ibukunolabinjo_3J wrote:This isn't about thermochemistry but science has made becoming spider man pretty possible ;)

https://www.sciencedaily.com/releases/2 ... 124957.htm

Even though I guess becoming a Spiderman also requires a strong body that can endure such great acceleration.
by 305127455
Sun Nov 18, 2018 7:46 pm
Forum: Administrative Questions and Class Announcements
Topic: Saying Thank You to Dr. Lavelle
Replies: 186
Views: 39256

Re: Saying Thank You to Dr. Lavelle

Thank you Dr.Lavelle for this quarter's great lectures and other studying experiences such as The Online Community. Also, your music does make me feel more relaxed, which is important for high study efficiency.
by 305127455
Sun Nov 11, 2018 2:36 pm
Forum: *Shrodinger Equation
Topic: Threshold Energy
Replies: 4
Views: 103

Re: Threshold Energy

The Psi here means the probability to find an electron in a certain space while the Psi in the photo electric effect means threshold energy.
by 305127455
Sun Nov 11, 2018 2:32 pm
Forum: Dipole Moments
Topic: Dipole moment
Replies: 4
Views: 39

Re: Dipole moment

So the reason why dipole force is always attractive is because molecules are always tend to be stable, and attracting each other to stay together is the way to do this?
by 305127455
Sun Nov 11, 2018 2:25 pm
Forum: Sigma & Pi Bonds
Topic: Midterm1
Replies: 10
Views: 139

Re: Midterm1

So those won't be involved in the final either?

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