Search found 39 matches
- Mon Jan 28, 2019 10:06 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: eq constant
- Replies: 1
- Views: 265
eq constant
Can we find equilibrium composition for a set of reactions using Gibbs minimization method?
- Mon Jan 28, 2019 10:02 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: eq constants for acids
- Replies: 4
- Views: 440
eq constants for acids
why do strong acids not have equilibrium constants? is it because the acid dissociates completely?
- Mon Jan 28, 2019 10:00 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Salts
- Replies: 1
- Views: 226
Salts
do salts affect the pH of a solution? how can we identify them as salts?
- Tue Jan 15, 2019 5:21 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Solids and liquids in equilibrium constants?
- Replies: 2
- Views: 244
Re: Solids and liquids in equilibrium constants?
They're not included because they do not affect the reactant amount at equilibrium in the reaction, so they are disregarded and kept at 1.
- Tue Jan 15, 2019 5:16 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Temperature
- Replies: 3
- Views: 291
Re: Temperature
Unless it says otherwise, we should be using Kelvin, and converting other units into Kelvin
- Tue Jan 15, 2019 4:36 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Exothermic vs. Endothermic Reaction
- Replies: 9
- Views: 3163
Re: Exothermic vs. Endothermic Reaction
I don't think you can tell whether a reaction is exothermic or endothermic by the equation alone. You have to either measure the heating to cooling or know enough about similar types of reactions.
- Sun Dec 09, 2018 8:55 pm
- Forum: Resonance Structures
- Topic: Resonance of CH3COOH
- Replies: 1
- Views: 2287
- Sun Dec 09, 2018 8:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Grade View
- Replies: 7
- Views: 906
Re: Final Grade View
I know that we get our physical tests back in the second week of winter quarter
- Sun Dec 09, 2018 8:49 pm
- Forum: Lewis Acids & Bases
- Topic: Ions as Bases
- Replies: 1
- Views: 368
- Sun Dec 09, 2018 8:48 pm
- Forum: Bronsted Acids & Bases
- Topic: Oxoacids
- Replies: 1
- Views: 595
Re: Oxoacids
As electron density of the O—H bond decreases, the bond becomes more polar. As the O—H becomes more polar, the oxoacid more readily dissolves in water. Therefore, acid strength increases as the number of oxygen attached to the central atom increases.
- Sat Dec 08, 2018 11:27 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polarizability and Polarizing Power
- Replies: 3
- Views: 432
Re: Polarizability and Polarizing Power
The polarizability of an atom increases the bigger the anion it is. The polarizing power of an atom increases the smaller the cation it is.
- Sat Dec 08, 2018 11:16 am
- Forum: Naming
- Topic: using prefix "mono"
- Replies: 2
- Views: 322
Re: using prefix "mono"
I'm pretty sure we don't use a prefix to identify one molecule. I'm pretty sure the first prefix we use is bis-.
- Sat Dec 08, 2018 11:14 am
- Forum: Biological Examples
- Topic: Ligands
- Replies: 7
- Views: 857
Re: Ligands
The ligand is also the same as the Lewis base in any given molecule, and the central atom is almost always the Lewis acid
- Sat Dec 08, 2018 11:11 am
- Forum: Biological Examples
- Topic: VSEPR model
- Replies: 2
- Views: 2521
Re: VSEPR model
VSEPR theory states that the electron pairs in the valence shell of an atom arrange themselves in such a way that repulsions among them are minimized and this arrangement of the electron pairs determines the shape of a particular molecule. Hybridization is the intermixing of a particular number of a...
- Sat Dec 08, 2018 11:08 am
- Forum: Bronsted Acids & Bases
- Topic: H vs OH
- Replies: 3
- Views: 434
H vs OH
Are A-H bonds stronger than AO-H bonds?
- Sat Dec 08, 2018 11:06 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2989427
Re: Post All Chemistry Jokes Here
Q: Why shouldn't you believe anything alcohol says?
A: 'Cause alkyl ha-lide
A: 'Cause alkyl ha-lide
- Sat Dec 08, 2018 11:05 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2989427
Re: Post All Chemistry Jokes Here
Q: What did the pregnant scientist say at the end of her electrolysis experiment?
A: "My water broke."
A: "My water broke."
- Tue Dec 04, 2018 2:22 pm
- Forum: Conjugate Acids & Bases
- Topic: Inductive Effect
- Replies: 5
- Views: 545
Inductive Effect
What is inductive effect? And how does it relate to electronegativity?
- Sun Nov 25, 2018 11:41 am
- Forum: Dipole Moments
- Topic: What are dipole moments used for?
- Replies: 3
- Views: 372
Re: What are dipole moments used for?
dipole moments refer to the distribution of electrons between two bonded atoms, normally between a polar and nonpolar bond. molecules with a net dipole moment are polar molecules. if the net dipole moment is zero or very small, the bond and molecule are considered to be nonpolar. atoms that have sim...
- Sun Nov 25, 2018 11:39 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2989427
Re: Post All Chemistry Jokes Here
Q: did you know proton's have mass?
A: i didn't even know they were catholic...
A: i didn't even know they were catholic...
- Sun Nov 25, 2018 11:36 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2989427
Re: Post All Chemistry Jokes Here
I would tell another chemistry joke...
... but all the good ones Argon
... but all the good ones Argon
- Mon Nov 19, 2018 6:54 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Different-looking N — H bonds in the Lewis structure for Ammonia (NH3)
- Replies: 3
- Views: 1116
Re: Different-looking N — H bonds in the Lewis structure for Ammonia (NH3)
The different bonds all essentially represent the same thing all they show is the 3D model of the molecule and how the atoms are all in different planes.
- Mon Nov 19, 2018 6:53 pm
- Forum: Bond Lengths & Energies
- Topic: VSEPR
- Replies: 6
- Views: 1985
Re: VSEPR
You would need to first draw the lewis structure for the compound, and then see how many bonds the molecule has and how many lone pairs the central atom as. Depending on that final number, you can determine the shape and the corresponding bond angle.
- Mon Nov 19, 2018 6:35 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem 14B
- Replies: 2
- Views: 296
Re: Chem 14B
math is an enforced co requisite so you would have to take a 3B, 31B, or LS30B the quarter before you take 14B or at the same time you take 14B
- Sun Nov 04, 2018 9:01 pm
- Forum: Octet Exceptions
- Topic: Radicals
- Replies: 16
- Views: 1660
Re: Radicals
How would you define a radical?
- Sun Nov 04, 2018 8:59 pm
- Forum: Lewis Structures
- Topic: 7th edition 2B.7
- Replies: 2
- Views: 244
Re: 7th edition 2B.7
From counting up all the lone pairs and bonds, you can calculate the total number of valence electrons for the compound. In this case, there are 32 VE. The diagram shows you how many Cl and O atoms are in the compound, so using that you can calculate the number of VE that come from those two atoms. ...
- Sun Nov 04, 2018 8:42 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Monday review sessions
- Replies: 2
- Views: 269
Re: Monday review sessions
I heard they're all going to be the same so it won't necessarily matter which lecture you decide to go to. You could always ask friends in other lectures for their notes as well if it's different!
- Mon Oct 29, 2018 8:22 pm
- Forum: Lewis Structures
- Topic: Number of Electrons
- Replies: 2
- Views: 98
Re: Number of Electrons
The number of protons is the same as the number of electrons if the atom is neutral and not charged. The number of valence electrons is based off of the group number the element is in.
- Mon Oct 29, 2018 8:20 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Energy Levels
- Replies: 2
- Views: 415
Re: Energy Levels
Electrons gain energy and become less stable as they move away from the nucleus. As it quantum number increases, the electron gains/absorbs energy from surroundings, which is also known as absorption of energy.
- Mon Oct 29, 2018 1:43 pm
- Forum: Octet Exceptions
- Topic: Sulfate Ion structure
- Replies: 2
- Views: 188
Re: Sulfate Ion structure
Sulfur is one of the exceptions to the octet rule. Sulfur is able to hold more than eight electrons due to its bonding. It's also a third period element which means the d sub level exists, and it has five d orbitals. Therefore, the additional d orbitals can accommodate for more electrons.
- Sun Oct 21, 2018 6:29 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Shape of Orbitals
- Replies: 3
- Views: 356
Re: Shape of Orbitals
lavelle mentioned that we will not be asked to draw the orbital shapes on our tests
- Sun Oct 21, 2018 1:17 pm
- Forum: Significant Figures
- Topic: Sig figs and percentages
- Replies: 3
- Views: 2217
Re: Sig figs and percentages
No, percentages do not count at sig figs.
- Sun Oct 21, 2018 1:12 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Atomic Spectroscopy vs Molecular Spectroscopy
- Replies: 1
- Views: 580
Re: Atomic Spectroscopy vs Molecular Spectroscopy
The main difference between the two is their energy levels. Molecular spectroscopy looks at the interactions between electrons in the outer valence shell and electromagnetic waves, which change based off of the structure and composition of the molecule. Atomic spectroscopy is only concerned with the...
- Mon Oct 15, 2018 2:34 pm
- Forum: Properties of Light
- Topic: 7th Edition HW 1B.27
- Replies: 1
- Views: 73
Re: 7th Edition HW 1B.27
to solve for minimum uncertainty you would use the uncertainty principle which is x=1/2(h/mv). the final answer should be x = 1.3 x 10^-36 m
- Mon Oct 15, 2018 2:32 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: 7th Edition HW 1D.21
- Replies: 3
- Views: 349
Re: 7th Edition HW 1D.21
a) 5d, five
b) 1s, one
c) 6f, seven
d) 2p, three
b) 1s, one
c) 6f, seven
d) 2p, three
- Mon Oct 15, 2018 2:29 pm
- Forum: General Science Questions
- Topic: BruinCast [ENDORSED]
- Replies: 4
- Views: 726
Re: BruinCast [ENDORSED]
if i remember correctly on the first day of class he said he doesn't bruin cast his lectures unfortunately
- Sun Oct 07, 2018 11:48 pm
- Forum: Balancing Chemical Reactions
- Topic: L. 31
- Replies: 2
- Views: 474
L. 31
The compound XCl2(NH3)2 can be formed by reacting XCl4 with NH3. Suppose that 3.571 g of XCl4 reacts with excess NH3 to give Cl2 and 3.180 g of XCl2(NH3)2. What is the element X?
I've been having trouble balancing the equation and identifying the mass of X?
I've been having trouble balancing the equation and identifying the mass of X?
- Sun Oct 07, 2018 11:44 pm
- Forum: Balancing Chemical Reactions
- Topic: 7th edition L.35
- Replies: 5
- Views: 668
Re: 7th edition L.35
the final balanced equation should be Fe3Br8 + 4Na2CO3 --> 8NaBr + 4CO2 + Fe3O4
- Sun Oct 07, 2018 10:48 pm
- Forum: Significant Figures
- Topic: Atlantic Pacific Rule
- Replies: 2
- Views: 1413
Re: Atlantic Pacific Rule
the rule states that if there is an Absence of a decimal point, you start counting from the right side of the number, and if there is a Presence of a decimal point you start counting from the left side of the number to determine how many significant figures there are overall.