## Search found 52 matches

Sat Dec 07, 2019 8:07 pm
Forum: Air Pollution & Acid Rain
Topic: dirty/clean coal
Replies: 6
Views: 134

### Re: dirty/clean coal

clean coal produces less So2 (less sulphurous acid thus less acid is reacting with water vapor to form acid rain)
Sat Dec 07, 2019 7:34 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Trigonal planar Polarity
Replies: 3
Views: 139

### Trigonal planar Polarity

Is trigonal planar polar if one of the attached atoms is different from the other two? Is it similar to how tetrahedral is only nonpolar if all four attached atoms are the same?
Thu Dec 05, 2019 8:33 pm
Forum: Conjugate Acids & Bases
Topic: Double Arrows
Replies: 3
Views: 66

### Double Arrows

I understand that you use a single arrow in an equation to show when a strong acid or base completely dissociates in water, but does that mean you use double arrows for everything that is not a strong acid or base? In the homework, none of the equations used double arrows. Would we be penalized on t...
Wed Dec 04, 2019 10:17 pm
Forum: Identifying Acidic & Basic Salts
Topic: Q6.21
Replies: 1
Views: 44

### Q6.21

Why do protons not bond to the oxygens? Aren't there two lone pairs on oxygen that two hydrogens can bond to?
Wed Dec 04, 2019 7:24 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate Potential
Replies: 2
Views: 49

### Polydentate Potential

How do you know if a ligand can be polydentate? I know that the metal can bond to the lone pairs but for example in Oxalate (C2O4 2-), it can be bidentate, but why is it not tetradentate?
Tue Dec 03, 2019 8:24 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acids
Replies: 13
Views: 226

### Re: Acids

A good list to know is this list of 7 strong acids: HCl, HBr, HI, H2SO4, HNO3, HClO3, HClO4 Also know that generally molecules with COOH are weak acids. is H2SO4 different from the others because it has two Hydrogens? It's different in that H2SO4 can dissociate twice, meaning it is polyprotic: H2SO...
Wed Nov 27, 2019 11:18 pm
Forum: Properties & Structures of Inorganic & Organic Bases
Topic: strength of base
Replies: 8
Views: 379

### Re: strength of base

Stronger acids would make weak bases because of its conjugate and vice versa.
Wed Nov 27, 2019 11:15 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acids
Replies: 13
Views: 226

### Re: Acids

A good list to know is this list of 7 strong acids: HCl, HBr, HI, H2SO4, HNO3, HClO3, HClO4
Also know that generally molecules with COOH are weak acids.
Wed Nov 27, 2019 11:12 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: How to take the log to get the pH?
Replies: 8
Views: 81

### Re: How to take the log to get the pH?

BeylemZ-4A wrote:would a really weak base be close to 7? or as far away from 7 as possible?

for example:
would a pH of 8 be more or less basic than a pH of 12?

a pH of 8 would be less basic than a pH of 12.
Wed Nov 27, 2019 11:09 pm
Forum: Amphoteric Compounds
Topic: Identifying Amphoteric Compounds
Replies: 2
Views: 55

### Identifying Amphoteric Compounds

I understand the definition of amphoteric compounds, but how do you identify them or do you have to memorize a list?
Wed Nov 27, 2019 11:08 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Final Exam
Replies: 10
Views: 178

### Re: Final Exam

It probably will because everything we have learned is connected and builds on top of each other.
Sat Nov 23, 2019 10:22 am
Forum: Naming
Topic: Prefixes
Replies: 4
Views: 76

### Re: Prefixes

Bis- , tris- tetrakis-, pentakis- are used if the ligand has the same prefix as the polydentate so you wouldn't be using the prefix "di " twice to name a compound. The ligand would be named with di and then name the polydentate with "bis".
Sat Nov 23, 2019 10:19 am
Forum: Naming
Topic: Diethylenetriamine
Replies: 2
Views: 36

### Re: Diethylenetriamine

Also, I think the difference between "ammine" and "amine" is that "ammine" is used when ammonia is acting as a ligand while "amine" is used when the compound formed ammonia by replacing hydrogen atoms with other hydrocarbons.
Sat Nov 23, 2019 10:15 am
Forum: Naming
Topic: Diethylenetriamine
Replies: 2
Views: 36

### Re: Diethylenetriamine

Ethylene comes before the ammine because the ligand goes before the ion in naming.
Sat Nov 23, 2019 10:01 am
Forum: Naming
Topic: oxidation states
Replies: 2
Views: 40

### Re: oxidation states

To find the oxidation state, you need to figure out the oxidation states of the other atoms in the molecule. For example in NiCl2, you know that each Cl is -1. Since the overall molecule has a neutral charge, Ni must be +2 to balance the two -1 for the Cl's.
Sat Nov 23, 2019 9:59 am
Forum: Bronsted Acids & Bases
Topic: Bronsted Acids
Replies: 2
Views: 44

### Re: Bronsted Acids

Carbonic Acid and Benzoic Acid are included in Bronsted acids because they are proton donors.
Sat Nov 23, 2019 9:54 am
Forum: Biological Examples
Topic: myoglobin and hemoglobin
Replies: 3
Views: 60

### Re: myoglobin and hemoglobin

I think it's first important to know that both transport O2 but myoglobin transports O2 in muscle cells and hemoglobin does so in blood. Also, Fe bound to porphyrin ligand makes up a heme complex and a heme complex bound to a protein makes up the myoglobin. Hemoglobin has 4 myoglobin like molecules,...
Fri Nov 15, 2019 8:46 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Angular/Bent Angles
Replies: 3
Views: 55

### Re: Angular/Bent Angles

AX2E follows trigonal planar where one of the bonds is a lone pair, thus the angles are less than 120 degrees.
Fri Nov 15, 2019 8:44 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: test 2
Replies: 13
Views: 148

### Re: test 2

I think we do.
Fri Nov 15, 2019 8:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: T Shape
Replies: 7
Views: 89

### T Shape

Do we have to know T shaped because it is in the homework, but we did not go over it in class
Fri Nov 15, 2019 8:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 6
Views: 62

### Re: Bond Angles

Typically shapes like bent or trigonal pyramidal have slightly less than a typical tetrahedral bond angle due to the number of electron pairs on the central atom.
Fri Nov 15, 2019 8:40 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: seesaw
Replies: 9
Views: 130

### Re: seesaw

The formula for seesaw is AX4E where there are 4 bonds and one lone pair. The bond from trigonal bipyramidal that is selected as a lone pair must be on the equitorial plane so there is less repulsion, making it more stable.
Fri Nov 08, 2019 8:59 pm
Forum: Dipole Moments
Topic: Polar
Replies: 9
Views: 143

### Re: Polar

You can tell if it is polar by electronegativity. If an atom has more electronegativity than the other, it will be partially negative, pulling electrons towards it, leaving the other atom partially positive
Fri Nov 08, 2019 8:56 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: Dispersion Force
Replies: 3
Views: 32

### Dispersion Force

Is the dispersion force just within the atom or is it also found between two atoms?
Fri Nov 08, 2019 8:54 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: Test 2
Replies: 6
Views: 108

### Re: Test 2

Will Test 2 just be on Molecular Shape and Structure? Will it be cumulative have questions from past topics like quantum world?
Fri Nov 08, 2019 8:50 pm
Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
Topic: Viscosity Picture?
Replies: 2
Views: 389

### Re: Viscosity Picture?

Pentane is a mobile fluid because the bods are weak. Pentadecane is a viscous fluid similar to a thick oil, and Octadecane is a waxy solid. The picture showed a metal rod dipping into each fluid.
Fri Nov 08, 2019 8:48 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: H bonds and Intermolecular Forces
Replies: 4
Views: 85

### Re: H bonds and Intermolecular Forces

The electrons are not being transferred or shared. Hydrogen bonding just shows the attraction between atoms
Sat Nov 02, 2019 1:19 pm
Forum: Trends in The Periodic Table
Topic: Electronegativity trend exception
Replies: 3
Views: 51

### Re: Electronegativity trend exception

Oxygen has lower electronegativity because it has an extra electron added to a half full orbital, creating electron-electron repulsion.
Sat Nov 02, 2019 1:16 pm
Forum: Bond Lengths & Energies
Topic: Bond Length (2D.13)
Replies: 2
Views: 43

### Re: Bond Length (2D.13)

First draw out the lewis structure for each example and compare bond lengths with single, double, or triple bonds. A triple bond has the strongest and shortest bond length while a single bond has the weakest and longest bond length.
Sat Nov 02, 2019 1:08 pm
Forum: Octet Exceptions
Topic: 2C5a Help
Replies: 2
Views: 47

### Re: 2C5a Help

Cl and O are single bonded and oxygen must follow the octet rule, so that's why Cl must be a radical
Sat Nov 02, 2019 1:03 pm
Forum: Lewis Structures
Topic: HW: 2.7
Replies: 1
Views: 49

### HW: 2.7

For question 2.7, when I drew the lewis structure for the N5+ cation, it had alternating single and double bonds, where each of the N atoms had 5 electrons except one (one 1+ formal charge). However, when I looked up the structure, it actually had 2 triple bonds and 2 single bonds with two 1+ formal...
Sat Nov 02, 2019 1:00 pm
Forum: Bond Lengths & Energies
Topic: HW: 2D Q5c
Replies: 2
Views: 38

### HW: 2D Q5c

When determining whether which compound has bonds with greater ionic character, do you use the difference in electronegativity between the atoms? If so, how can you tell if C-O electronegativity difference is greater than that of C-S?
Sun Oct 27, 2019 4:41 pm
Forum: Student Social/Study Group
Topic: Study Tips
Replies: 58
Views: 2149

### Re: Study Tips

Besides doing practice problems, I like to retake my notes again even though it is time consuming. This way, I can understand and remember the conceptual parts of the topics better.
Sun Oct 27, 2019 4:39 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: S-orbitals symmetry
Replies: 4
Views: 75

### Re: S-orbitals symmetry

The sizes of the two lobes of the p orbitals are different sizes, so px, py, and pz are different
Sun Oct 27, 2019 4:33 pm
Forum: Resonance Structures
Topic: Compounds with Resonance
Replies: 1
Views: 42

### Compounds with Resonance

Why are compounds with resonance structures more stable?
Sun Oct 27, 2019 4:32 pm
Forum: Octet Exceptions
Topic: expanded valence shells
Replies: 4
Views: 39

### Re: expanded valence shells

The d orbitals can accommodate the extra valence electrons
Sun Oct 27, 2019 4:18 pm
Forum: Ionic & Covalent Bonds
Topic: 2A.23
Replies: 5
Views: 66

### Re: 2A.23

Amy Luu 3L wrote:I'm confused on part d of the problem. Why is hydrogen telluride H2Te? I don't know how to get this since i thought hydrogen would want to gain an electron so it would also be an anion?

Telluride has a 2-, so it would need two Hydrogens since each Hydrogen has a 1+ charge.
Sat Oct 19, 2019 9:05 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Hund's rule and Pauli Exclusion Principle
Replies: 14
Views: 224

### Re: Hund's rule and Pauli Exclusion Principle

Pauli Exclusion Principle simply states that in each orbital there are two electrons with opposite spin. Hund's rule states that each orbital should be filled up once before the second electron is added. It's also known as "the bus seat rule". On a bus, you want to maximize the seating so ...
Sat Oct 12, 2019 4:49 pm
Forum: Photoelectric Effect
Topic: Molecular Spectroscopy
Replies: 3
Views: 76

### Re: Molecular Spectroscopy

Molecular spectroscopy can be used to identify molecules, since each element has a certain pattern like a fingerprint.
Sat Oct 12, 2019 4:41 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Test 1 [ENDORSED]
Replies: 107
Views: 5114

### Re: Test 1[ENDORSED]

Does anyone know when we will be receiving our tests back?
Sat Oct 12, 2019 4:40 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect diagram
Replies: 3
Views: 86

### Re: Photoelectric Effect diagram

The detector is a machine that detects the speed of the particle. This will allow us to calculate other measures like de Broglie wavelength.
Sat Oct 05, 2019 10:36 pm
Forum: Quantum Numbers and The H-Atom
Topic: HW question 2.17 [ENDORSED]
Replies: 4
Views: 862

### Re: HW question 2.17[ENDORSED]

To find the number of orbitals in a subshell using l, there is a formula:
# orbitals = 2l + 1
Sat Oct 05, 2019 10:34 pm
Forum: Einstein Equation
Topic: Planack's constant
Replies: 8
Views: 197

### Re: Planack's constant

Planck's Constant is used in the following equations:
E=hv (Energy = h * frequency)
E = (-hR)/n^2 (Energy = (-hR)/(energy level)^2
Sat Oct 05, 2019 10:29 pm
Forum: Limiting Reactant Calculations
Topic: Order of atoms in molecules
Replies: 6
Views: 98

### Re: Order of atoms in molecules

If carbon is in the molecule, it is usually written first, and hydrogen is second. For now, I think we just need to know that hydrogen and metals come first and nonmetals are second.
Sat Oct 05, 2019 10:27 pm
Forum: Balancing Chemical Reactions
Topic: balancing charges
Replies: 4
Views: 88

### Re: balancing charges

Balancing charges are used in balancing redox equations, so I don't think we need to worry about that yet.
Sat Oct 05, 2019 10:24 pm
Forum: Significant Figures
Topic: All students read this sig fig post [ENDORSED]
Replies: 131
Views: 17182

### Re: All students read this sig fig post[ENDORSED]

For the upcoming test on Tuesday, will we be penalized for having incorrect sig figs?
Thu Oct 03, 2019 9:55 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Wavelength Plausibility
Replies: 31
Views: 1449

### Wavelength Plausibility

In the lecture slides, it said that an electron's wavelength is around 10^-12m. In the modules it asks if certain wavelengths are able to be detected. I just wanted to confirm that if the wavelength smaller than 10^-12, it is detectable. But how much smaller is detectable? Is ~10^-15m acceptable?
Thu Oct 03, 2019 9:48 pm
Forum: Balancing Chemical Reactions
Topic: H.5
Replies: 2
Views: 74

### Re: H.5

First, you notice that there are 6N on the left and only 3N for products. Thus, multiply HN3 by 2. After, there are 2H for reactants and 4 for products. Therefore, multiply H2O by 2. This will finalize balancing the equation:
Mg(N3)2 + 2H2O -> Mg(OH)2 + 2HN3
Thu Oct 03, 2019 9:42 pm
Forum: Properties of Electrons
Topic: Wave Properties of Electrons- Module Question
Replies: 3
Views: 395

### Re: Wave Properties of Electrons- Module Question

They experience particle and wave like properties as shown in the slit experiment. If it passes through the slits and hits the detector directly, it is behaving like a particle. However, if it forms a diffraction pattern, it is behaving like a wave - similar to what happens when an incident of light...
Thu Oct 03, 2019 9:38 pm
Forum: DeBroglie Equation
Topic: Units for DeBroglie
Replies: 4
Views: 95

### Re: Units for DeBroglie

You use kg and m because those are the SI units used in the formula.
Thu Oct 03, 2019 9:37 pm
Forum: Balancing Chemical Reactions
Topic: Compound names
Replies: 11
Views: 196

### Re: Compound names

I don't think we have to know all the naming rules at the moment, but I think it would be useful to know some basics since they keep appearing in the homework: If the compound is ionic, you add an "ide" to the end (e.g. NaCl is sodium chloride) Useful Polyatomics: (NO3 nitrate, NO2 nitrite...
Thu Oct 03, 2019 9:32 pm
Forum: Molarity, Solutions, Dilutions
Topic: Clarification
Replies: 7
Views: 155

### Re: Clarification

Moles of solute do not change even when more solvent is added because there is no solute being added or removed. It is easier to think that when more solvent is added, it is being added to its surrounding so the solute and solvent are separate.