Search found 50 matches
- Sun Dec 08, 2019 5:25 pm
- Forum: Naming
- Topic: bis,tris,tetrakis
- Replies: 6
- Views: 178
Re: bis,tris,tetrakis
These prefixes typically apply to polydentate ligands.
- Sun Dec 08, 2019 5:23 pm
- Forum: Naming
- Topic: Naming the metal
- Replies: 3
- Views: 150
Re: Naming the metal
If the overall charge of the compound is negative, then you add an -ate, otherwise you just state the metal. There are actually exceptions to this -ate rule. Copper -> cuprate and iron -> ferrate.
- Sun Dec 08, 2019 5:21 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pH sig figs
- Replies: 11
- Views: 166
Re: pH sig figs
You count the sig figs after the decimal point when calculating with logs.
- Sun Dec 08, 2019 5:20 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Fundamentals
- Replies: 5
- Views: 162
Re: Fundamentals
We didn't cover those topics. At least not in very much detail, so I don't think you would have to know them.
- Sat Dec 07, 2019 11:08 pm
- Forum: Biological Examples
- Topic: Cisplatin
- Replies: 5
- Views: 208
Cisplatin
Why can the cis- version of the complex form 2 bonds and why can the trans- version of the complex only form 1 bond?
- Sat Dec 07, 2019 11:04 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Chelate
- Replies: 2
- Views: 143
Chelate
How can we tell if the chelate is square planar or tetrahedral? Will we have to choose between the two on the final?
- Sat Dec 07, 2019 5:07 pm
- Forum: Lewis Acids & Bases
- Topic: bases
- Replies: 5
- Views: 216
Re: bases
Strong bases are completely ionized in water and consist of alkali metal and alkali earth metal oxides (groups 1 and 2). Weak bases are not completely ionized in water like ammonia.
- Sat Dec 07, 2019 5:06 pm
- Forum: Lewis Acids & Bases
- Topic: acids
- Replies: 2
- Views: 142
Re: acids
Strong acids produce more protons in a solution than weak acids. Strong acids also assumed to be 100% ionized/dissociated in a solution while weak acids are not.
- Sat Dec 07, 2019 5:04 pm
- Forum: Lewis Acids & Bases
- Topic: Lewis vs Bronsted
- Replies: 1
- Views: 61
Lewis vs Bronsted
What are some example of compounds that are Lewis acids/bases but not Bronsted acids/bases? And vice versa?
- Sat Dec 07, 2019 4:58 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron config for copper
- Replies: 2
- Views: 137
Re: Electron config for copper
The 3d10 and 4s1 implies that the 4s shell gave one electron to the 3d shell in order to make it more stable. 3d9 and 4s2 -> 3d10 and 4s1 is an exception made by copper. Also the 4s shell is written before the 3d because it has higher energy. Reading it off the periodic table can be confusing becaus...
- Sat Dec 07, 2019 4:51 pm
- Forum: Industrial Examples
- Topic: what examples should we know?
- Replies: 4
- Views: 198
Re: what examples should we know?
Cisplatin and porphyrin(->heme complex->myoglobin->hemoglobin) seem like important biological examples that have come up.
Re: cisplatin
Cisplatin is well known for being used in chemotherapy. It forms a coordination compound with DNA to stop cell division.
- Sat Dec 07, 2019 4:45 pm
- Forum: Coordinate Covalent Bonds
- Topic: Hybridization
- Replies: 1
- Views: 139
Re: Hybridization
I've seen the questions worded as "Identify the composition of each bond and the hybridization of each lone pair" for questions that use that notation. I'm not sure if this is the situation you are talking about, but for example the hybridization of lone pairs of oxygen can look like O(sp ...
- Sat Dec 07, 2019 4:37 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Why is NO2- monodentate?
- Replies: 1
- Views: 72
Re: Why is NO2- monodentate?
I went to a review session and essentially the TA explained that there isn't enough room on a single N to have multiple sites. He said think of each individual atom as a site instead of lone pair.
- Sat Dec 07, 2019 4:35 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Identical Values for Quantum Numbers
- Replies: 1
- Views: 128
Identical Values for Quantum Numbers
This was a question on the midterm. "How many electrons in bromine possess identical values for the first two quantum numbers, n and l, as the unpaired electrons? Include the unpaired electron in you answer." How do we find the amount of electrons with identical values?
- Thu Dec 05, 2019 9:53 pm
- Forum: Sigma & Pi Bonds
- Topic: Marshmallow 41.C
- Replies: 3
- Views: 194
Marshmallow 41.C
“Which pair of atoms in thymine are most tightly bound and why? C=C, C=O, C=N”
Sorry if sigma and pi bonds don’t relate to this question.
Sorry if sigma and pi bonds don’t relate to this question.
- Tue Dec 03, 2019 9:43 pm
- Forum: Bronsted Acids & Bases
- Topic: Self-Test J.1A
- Replies: 1
- Views: 50
Self-Test J.1A
Why is C6H6 neither an acid nor a base?
- Tue Dec 03, 2019 7:46 pm
- Forum: *Shrodinger Equation
- Topic: schrodingers equation
- Replies: 8
- Views: 264
Re: schrodingers equation
We may not have to do any calculations using the equation, but my TA said we should understand Schrodiner's equation conceptually.
- Tue Dec 03, 2019 7:44 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pOH Trends
- Replies: 3
- Views: 66
pOH Trends
Does higher pOH indicate a more basic or acidic solution?
- Mon Nov 18, 2019 6:59 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar and Nonpolar Question [ENDORSED]
- Replies: 4
- Views: 1024
Polar and Nonpolar Question [ENDORSED]
For question 2E.25(a), could you draw the lewis structure for CH2Cl2 so that the dipole moments cancel out? What makes this molecule polar?
- Sun Nov 17, 2019 11:18 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Notation
- Replies: 4
- Views: 109
Re: VSEPR Notation
A is the central atom and is typically 1. X is the number of atoms bonded to the central atom. E is the number of lone pairs around the central atom, A. The VSEPR formulas is very useful in determining the shape of the molecule.
- Sun Nov 17, 2019 11:16 pm
- Forum: Trends in The Periodic Table
- Topic: electron affinity
- Replies: 7
- Views: 253
Re: electron affinity
Electron affinity increase going to the right and upwards along the periodic table. It is the same trend as electronegativity. You can always look in the direction of Flourine since it's the element with the highest electronegativity.
- Sun Nov 17, 2019 11:10 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: dipole moments
- Replies: 11
- Views: 146
Re: dipole moments
Dipoles cancel when dipole moments of equal strength go in opposite directions.
- Sun Nov 17, 2019 11:09 pm
- Forum: Ionic & Covalent Bonds
- Topic: Strength and Length
- Replies: 18
- Views: 277
Re: Strength and Length
In general, the longer the bond length, the weaker it is. Also, multiple bonds results in short bonds meaning they are generally stronger.
- Sun Nov 17, 2019 10:58 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Double and triple bonds
- Replies: 4
- Views: 84
Re: Double and triple bonds
Double and triple bonds aren't considered because the VSEPR model focuses on the regions of electron concentration. Each bond, whether single or multiple, acts as a single unit when counting regions of high electron concentration.
- Sun Nov 03, 2019 11:20 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Magnetic Quantum Number
- Replies: 3
- Views: 43
Magnetic Quantum Number
When finding the magnetic quantum number ms, is it always+ 1/2? Or can the spin orientation be found?
- Sun Nov 03, 2019 11:03 pm
- Forum: Resonance Structures
- Topic: Drawing Resonance Structures
- Replies: 2
- Views: 60
Re: Drawing Resonance Structures
Since the arrangements of the electrons remain the same, I don't believe you'll have to draw separate resonance structures.
- Sun Nov 03, 2019 10:53 pm
- Forum: General Science Questions
- Topic: Step Up Sessions
- Replies: 3
- Views: 59
Re: Step Up Sessions
The step up sessions for Monday (no step-up sessions Tuesday) are in Young Hall Room 1032-3 from 11AM-12PM and Room 1023-1 from 1-2PM. You can find out more from this link: https://lavelle.chem.ucla.edu/wp-content/supporting-files/Chem14A/Chem14UA_PL_ALL.pdf
- Sun Nov 03, 2019 10:49 pm
- Forum: General Science Questions
- Topic: Step Up Sessions
- Replies: 3
- Views: 59
Re: Step Up Sessions
Step-up sessions could help reinforce your knowledge of a topic even if you have a firm grasp on it. I'd recommend going if you want practice and review.
- Fri Nov 01, 2019 11:37 am
- Forum: Octet Exceptions
- Topic: Expanded Valence Shells
- Replies: 2
- Views: 44
Expanded Valence Shells
How many more valence electrons can phosphorus, sulfur, and chlorine accommodate with their expanded valence shells? Why?
- Sun Oct 27, 2019 9:49 pm
- Forum: Resonance Structures
- Topic: Equal Bond Length
- Replies: 4
- Views: 70
Re: Equal Bond Length
Single and double bonds are drawn in Lewis dot structures, but those bonds are capable of being different equivalent locations. Electrons move around so that actual bond length is equal, representing the average bond length of the structure. This is represented in resonance.
- Sun Oct 27, 2019 9:36 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal charge
- Replies: 3
- Views: 60
Re: Formal charge
Yes, you find the formal charge of each bound atom.
- Sun Oct 27, 2019 9:35 pm
- Forum: Resonance Structures
- Topic: Drawing Resonance Structures
- Replies: 3
- Views: 76
Drawing Resonance Structures
How should resonance structures be drawn? The arrows indicated between the various structures or the organic chemistry shapes?
- Sun Oct 27, 2019 9:20 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Finding Most Stable Structure
- Replies: 9
- Views: 93
Finding Most Stable Structure
How do we determine which structure is the most stable with formal charge?
- Sun Oct 27, 2019 8:55 pm
- Forum: Resonance Structures
- Topic: Resonance
- Replies: 5
- Views: 67
Re: Resonance
Resonance is the blending of electron structures. They have the same arrangement of atoms but different arrangements of electrons.
- Sun Oct 20, 2019 9:34 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Spin Quantum Number
- Replies: 3
- Views: 77
Re: Spin Quantum Number
Positive means it's spinning up, negative means it's spinning down.
- Sun Oct 20, 2019 9:33 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect
- Replies: 7
- Views: 110
Re: Photoelectric Effect
Increasing the intensity of light does not result in an ejected electron because in this experiment, the light is acting as particles (photons). Increasing the light would only increase the amount of photons, not how much energy each photon has. So if one photon doesn't have enough energy to eject a...
- Sun Oct 20, 2019 9:24 pm
- Forum: Naming
- Topic: Naming Compounds (general question)
- Replies: 9
- Views: 156
Re: Naming Compounds (general question)
My TA recommended learning polyatomic ions, which will help you determine certain formulas from word problems. Here's a link to a few common ones: http://www.iun.edu/~cpanhd/C101webnotes ... salts.html
- Sun Oct 20, 2019 9:19 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Quantum Number
- Replies: 3
- Views: 45
Re: Quantum Number
The principal quantum number (n) tells you which energy level (shell) the electron is in. The angular momentum quantum number (l) describes the shape/orbital (s,p,d,f). The magnetic quantum number (m) labels different orbitals of a subshell/orientation.
- Sun Oct 20, 2019 9:12 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: M Value
- Replies: 3
- Views: 48
M Value
How is the m value determined within a set of quantum number?
- Sun Oct 13, 2019 9:11 pm
- Forum: Properties of Electrons
- Topic: Decrease in Quantum level
- Replies: 3
- Views: 29
Decrease in Quantum level
A few clarifying questions about when an electron transitions quantum levels. When they transition to a lower level, do electrons decrease the energy of an electron? Does that decrease in energy for the electrons increase the frequency of light emitted?
- Sun Oct 13, 2019 8:53 pm
- Forum: Limiting Reactant Calculations
- Topic: How to find which reactant is limiting?
- Replies: 3
- Views: 206
Re: How to find which reactant is limiting?
You would have to compare those calculated moles to the required moles. An easy way to look at it is using ratios. You could find the value of one mole and apply that to ratio of moles of the chemical equation. Using the ratio, you can determine how many moles are needed for the other reactants by d...
- Sun Oct 13, 2019 8:37 pm
- Forum: Properties of Light
- Topic: Diffraction Patterns
- Replies: 2
- Views: 29
Diffraction Patterns
How do constructive and destructive interference interact to create diffraction patterns of light? What is the relationship?
- Sun Oct 13, 2019 8:25 pm
- Forum: Properties of Light
- Topic: De Broglie's Equation
- Replies: 4
- Views: 40
Re: De Broglie's Equation
You would use De Broglie's equation for any moving particle with momentum and has wavelike properties with wavelength. You would typically use it for small objects with a small enough mass. Typically, a wavelength with less than 10^15 meters dies not have wavelength properties.
- Sun Oct 13, 2019 8:13 pm
- Forum: Properties of Electrons
- Topic: Photoelectric Effect
- Replies: 3
- Views: 47
Re: Photoelectric Effect
The "unexpected" aspect of the photoelectric effect is the fact that, unless there are greater than or equal photons to energy remove electrons, electrons are not emitted for even high intensity light.
- Thu Oct 03, 2019 10:24 pm
- Forum: Significant Figures
- Topic: Next Week's Test 1
- Replies: 9
- Views: 240
Re: Next Week's Test 1
I believe it will be different for every TA, but my TA said the correct use of sig figs will be part of his grading.
- Thu Oct 03, 2019 9:42 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Gaseous Mixtures
- Replies: 2
- Views: 91
Gaseous Mixtures
Can someone elaborate a quick statement from the textbook? "In practice, gaseous mixtures are not thought of as solutions, even though one gas might be dominant (such as nitrogen in the atmosphere)." Is it improper to call gaseous mixtures solutions? Or are gaseous mixtures incapable of be...
- Thu Oct 03, 2019 9:31 pm
- Forum: Significant Figures
- Topic: quick sig fig question
- Replies: 3
- Views: 70
Re: quick sig fig question
The first zero, the leading zero, is not significant.
- Thu Oct 03, 2019 9:27 pm
- Forum: Balancing Chemical Reactions
- Topic: Homework
- Replies: 4
- Views: 85
Re: Homework
I think the left side is what is typically used for APA (and MLA) format.
- Thu Oct 03, 2019 9:23 pm
- Forum: Significant Figures
- Topic: Sig Figs of Mass Percentage Composition?
- Replies: 3
- Views: 70
Sig Figs of Mass Percentage Composition?
I was wondering how many sig figs do we apply to percentages when we're only given a molecular/empirical formula.