Search found 30 matches
- Fri Dec 07, 2018 10:01 pm
- Forum: Air Pollution & Acid Rain
- Topic: Acid Rain
- Replies: 24
- Views: 3813
Re: Acid Rain
Mainly caused by chemicals like SO4^2- and NO3- coming from burning fossil fuels, such as coal.
- Fri Dec 07, 2018 9:56 pm
- Forum: Biological Examples
- Topic: Ligands
- Replies: 6
- Views: 959
Re: Ligands
Magnesium ligands are in chlorophyll and critical for electron transport chain there.
- Fri Dec 07, 2018 9:51 pm
- Forum: DeBroglie Equation
- Topic: De Brogile Application
- Replies: 4
- Views: 774
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.
- Fri Dec 07, 2018 9:44 pm
- Forum: Ionic & Covalent Bonds
- Topic: Boiling point
- Replies: 5
- Views: 812
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.
- Fri Dec 07, 2018 9:39 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: How to tell which ligands can be polydentrate
- Replies: 4
- Views: 458
Re: How to tell which ligands can be polydentrate
The angle between two ligands need to be around 90˚.
- Fri Dec 07, 2018 9:35 pm
- Forum: Electronegativity
- Topic: Electronegativity
- Replies: 5
- Views: 762
Re: Electronegativity
Nitrogen is more electro negative since it has more protons than carbon does.
- Fri Dec 07, 2018 9:25 pm
- Forum: Conjugate Acids & Bases
- Topic: Determining Conjugate Acid
- Replies: 5
- Views: 871
Re: Determining Conjugate Acid
We just add an H+, and for determining the conjugate base, just subtract an H+.
- Fri Dec 07, 2018 9:20 pm
- Forum: Bronsted Acids & Bases
- Topic: Lewis Acids and Bases and Bronsted?
- Replies: 5
- Views: 599
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+.
- Fri Dec 07, 2018 9:14 pm
- Forum: Bronsted Acids & Bases
- Topic: acidity
- Replies: 4
- Views: 564
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.
- Thu Dec 06, 2018 8:31 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Focus 9C.3 Part d
- Replies: 3
- Views: 417
Re: Focus 9C.3 Part d
Water is "aqua", which starts with "A."
- Thu Dec 06, 2018 8:29 pm
- Forum: Conjugate Acids & Bases
- Topic: Neutralization Reactions
- Replies: 6
- Views: 946
Re: Neutralization Reactions
Taking H2O as another product of the reaction and filling the reactants should work.
- Thu Dec 06, 2018 8:20 pm
- Forum: Conjugate Acids & Bases
- Topic: Conjugate Bases
- Replies: 7
- Views: 2540
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...
- Wed Dec 05, 2018 9:32 pm
- Forum: Naming
- Topic: 7th edition 9.C1
- Replies: 2
- Views: 435
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
For example:
Fe: -ferrate
- Wed Dec 05, 2018 9:26 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligands
- Replies: 4
- Views: 521
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.
- Wed Dec 05, 2018 9:21 pm
- Forum: Naming
- Topic: Water as a ligand
- Replies: 5
- Views: 584
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.
- Tue Dec 04, 2018 8:35 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: Salt + Water?
- Replies: 2
- Views: 565
Re: Salt + Water?
In the scope of 14A, yes I think.
- 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: 605
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 - ...
- Tue Dec 04, 2018 8:29 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: pH formula?
- Replies: 69
- Views: 3565
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-])
- Sun Dec 02, 2018 8:13 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: How to determine shape of coordination compound
- Replies: 3
- Views: 484
Re: How to determine shape of coordination compound
Looking at the formula and calculating bonds and valence electrons should do.
- Sun Dec 02, 2018 8:09 pm
- Forum: Hybridization
- Topic: lone pairs
- Replies: 20
- Views: 1989
Re: lone pairs
Long pairs does count, and memorizing this and "formula" of hybridization should be enough to solve most of the related problems.
- Sun Dec 02, 2018 8:04 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Nodal planes
- Replies: 6
- Views: 1283
Re: Nodal planes
I don' t think we need to remember that. Perhaps the question will give us a diagram and let us tell.
- Sun Nov 25, 2018 7:42 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Naming the Shape
- Replies: 16
- Views: 1206
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.
- Sun Nov 25, 2018 7:38 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Shapes Not covered in Lecture
- Replies: 10
- Views: 1077
Re: Shapes Not covered in Lecture
I guess it's better to memorize that since it may be included in questions.
- Sun Nov 25, 2018 7:33 pm
- Forum: Bond Lengths & Energies
- Topic: Drawing resonance structures?
- Replies: 6
- Views: 665
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.
- Sun Nov 18, 2018 7:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pair?
- Replies: 4
- Views: 523
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.
- Sun Nov 18, 2018 7:50 pm
- Forum: Student Social/Study Group
- Topic: Chemistry News
- Replies: 135
- Views: 163715
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.
- Sun Nov 18, 2018 7:46 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Saying Thank You to Dr. Lavelle
- Replies: 490
- Views: 513496
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.
- Sun Nov 11, 2018 2:36 pm
- Forum: *Shrodinger Equation
- Topic: Threshold Energy
- Replies: 4
- Views: 729
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.
- Sun Nov 11, 2018 2:32 pm
- Forum: Dipole Moments
- Topic: Dipole moment
- Replies: 4
- Views: 405
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?
- Sun Nov 11, 2018 2:25 pm
- Forum: Sigma & Pi Bonds
- Topic: Midterm1
- Replies: 10
- Views: 1113
Re: Midterm1
So those won't be involved in the final either?