Search found 54 matches
- Sat Dec 07, 2019 7:43 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: H20
- Replies: 4
- Views: 250
H20
Why is H2O a monodentate when it has 2 pairs of lone electrons?
Re: Ligands
^^^Thank you
Ligands
This might be a dumb question but are polydenate ligands and bidenate ligands the same thing?
- Sat Dec 07, 2019 12:41 pm
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 336760
Re: Final Jitters
Yes getting as much studying done as possible is beneficial but remember to take breaks in between so you don't overwhelm yourself.
- Sat Dec 07, 2019 12:39 pm
- Forum: General Science Questions
- Topic: Final
- Replies: 3
- Views: 428
Re: Final
I believe the final is cumulative but i would focus more on the info after the midterm.
- Sat Dec 07, 2019 12:04 pm
- Forum: Properties of Light
- Topic: 1b.
- Replies: 1
- Views: 197
1b.
Can someone help
1B.9 A lamp rated at 32 W emits violet light of wavelength 420 nm. How many photons of violet light can the lamp generate in 2.0 s? How many moles of photons are emitted in that time interval?
1B.9 A lamp rated at 32 W emits violet light of wavelength 420 nm. How many photons of violet light can the lamp generate in 2.0 s? How many moles of photons are emitted in that time interval?
- Sat Dec 07, 2019 12:01 pm
- Forum: Ionic & Covalent Bonds
- Topic: Nonpolar and polar
- Replies: 16
- Views: 1067
Nonpolar and polar
Whats the easiest ways to tell whether a molecule is polar or non-polar?
- Fri Dec 06, 2019 9:13 pm
- Forum: Naming
- Topic: writing formula of a given name
- Replies: 5
- Views: 390
Re: writing formula of a given name
Write the names of the ligands in the following order: neutral, negative, positive. If there are multiple ligands of the same charge type, they are named in alphabetical order.
- Fri Dec 06, 2019 9:07 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: electron withdrawing groups
- Replies: 1
- Views: 301
Re: electron withdrawing groups
An electron withdrawing group draws electrons away from a reaction center. When this center is an electron rich carbanion or an alkoxide anion, the presence of the electron-withdrawing substituent has a stabilizing effect. Electron withdrawing group are atoms or groups that draw electron density fro...
- Fri Dec 06, 2019 9:03 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Topics
- Replies: 2
- Views: 168
Re: Final Topics
I think it will be everything from the fundamentals to post midterm topics. But I would mostly focus post midterm.
- Fri Dec 06, 2019 9:00 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Sharing resources
- Replies: 1
- Views: 288
- Fri Dec 06, 2019 8:50 pm
- Forum: Naming
- Topic: How to find out the oxidation number?
- Replies: 3
- Views: 318
Re: How to find out the oxidation number?
The oxidation number of an atom is zero in a neutral substance that contains atoms of only one element. Atoms in O2, O3, P4, S8, and aluminum metal all have an oxidation number of 0. The oxidation number of simple ions is equal to the charge on the ion. The oxidation number of sodium in the Na+ ion ...
- Fri Dec 06, 2019 8:41 pm
- Forum: Polyprotic Acids & Bases
- Topic: bases
- Replies: 2
- Views: 232
Re: bases
Some examples would be Ba(OH)2, PO4^3-, SO4^2-
- Fri Dec 06, 2019 8:37 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Relative Acidity: e- withdrawing groups
- Replies: 2
- Views: 280
Re: Relative Acidity: e- withdrawing groups
An atom or group that draws electron density from neighboring atoms towards itself, usually by resonance or inductive effects
- Fri Dec 06, 2019 8:30 pm
- Forum: Administrative Questions and Class Announcements
- Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
- Replies: 115
- Views: 12368
Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
For number 21 what is the oxidation state of iron?
- Thu Dec 05, 2019 9:12 pm
- Forum: Properties & Structures of Inorganic & Organic Bases
- Topic: 6B.5
- Replies: 8
- Views: 1458
6B.5
Hi, could someone help me approach this? 6B.5 Calculate the pH and pOH of each of the following aqueous solutions of a strong acid or base: (a) 0.0146 m HNO3(aq); (b) 0.11 m HCl(aq); (c) 0.0092 m Ba(OH)2(aq); (d) 2.00 mL of 0.175 m KOH(aq) after dilution to 0.500 L; (e) 13.6 mg of NaOH dissolved in ...
- Thu Dec 05, 2019 9:07 pm
- Forum: Amphoteric Compounds
- Topic: 6A.17
- Replies: 2
- Views: 309
6A.17
Could someone explain amphoteric
6A.17 State whether the following oxides are acidic, basic, or
amphoteric: (a) BaO; (b) SO3; (c) As2O3; (d) Bi2O3.
6A.17 State whether the following oxides are acidic, basic, or
amphoteric: (a) BaO; (b) SO3; (c) As2O3; (d) Bi2O3.
- Wed Dec 04, 2019 8:30 pm
- Forum: Student Social/Study Group
- Topic: Grades
- Replies: 14
- Views: 947
Re: Grades
I doubt that their will be a curve especially since a C in the class is 50%.
- Tue Dec 03, 2019 6:53 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Strong vs. Weak Acids and Bases
- Replies: 4
- Views: 268
Re: Strong vs. Weak Acids and Bases
Strong acids usually have very high electronegativity
- Mon Dec 02, 2019 10:10 pm
- Forum: Bronsted Acids & Bases
- Topic: stronger acid ?
- Replies: 8
- Views: 389
Re: stronger acid ?
Usually the stronger acid is the element with the higher electronegativity.
- Mon Dec 02, 2019 10:03 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Number
- Replies: 9
- Views: 457
Re: Coordination Number
The value depends on the relative sizes of the central atom and ligands and by the charge from the electronic configuration of an ion. The coordination number of an atom in a molecule or polyatomic ion is found by counting the number of atoms bound to it
- Mon Dec 02, 2019 10:00 pm
- Forum: General Science Questions
- Topic: 50 post grade
- Replies: 25
- Views: 1760
Re: 50 post grade
I think they just count them after week 10 to make sure you've done the posts
- Mon Dec 02, 2019 9:58 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: pKa vs Ka
- Replies: 6
- Views: 463
Re: pKa vs Ka
The dissociation constant Ka is usually written as a quotient of the equilibrium concentrations (in mol/L), denoted by [HA], [A−] and [H3O+]. Relationship between Ka, pKa and acid strength: The smaller the value of Ka, the larger the value of pKa, the weaker the acid.
- Mon Dec 02, 2019 9:39 pm
- Forum: Student Social/Study Group
- Topic: Practice Final
- Replies: 17
- Views: 1354
Practice Final
Will Lavelle be giving a practice final in preparation for Sunday?
- Mon Dec 02, 2019 9:37 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Grades
- Replies: 15
- Views: 980
Re: Grades
yes a 50% is a C which is passing.
- Mon Dec 02, 2019 9:36 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam Location
- Replies: 11
- Views: 709
Re: Final Exam Location
Lavelle will probably send an email to inform everyone which room they will be taking the test in.
- Thu Nov 21, 2019 8:00 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Test 2
- Replies: 3
- Views: 185
Test 2
Is test 2 only covering VSEPR models?
- Mon Nov 18, 2019 9:46 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Advice for studying
- Replies: 92
- Views: 6541
Re: Advice for studying
I feel like the step up programs have helped a lot and just reviewing practice problems would be the best.
- Sun Nov 17, 2019 7:41 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: HW# 2E.26
- Replies: 2
- Views: 98
HW# 2E.26
Draw the Lewis structure and predict whether each of the
following molecules is polar or nonpolar: (a) H2Se; (b) AsF5;
(c) SiO2; (d) NF3.
Any easy rules to remember to find out if a molecule is polar or nonpolar?
following molecules is polar or nonpolar: (a) H2Se; (b) AsF5;
(c) SiO2; (d) NF3.
Any easy rules to remember to find out if a molecule is polar or nonpolar?
- Sun Nov 17, 2019 7:33 pm
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 336760
Re: Final Jitters
Personally I like to meditate and go over breathing exercises to get myself focused on something else
- Sun Nov 17, 2019 7:30 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Other VSEPR shapes?
- Replies: 2
- Views: 157
Re: Other VSEPR shapes?
I believe that whatever's been reviewed during lecture and section are the most relevant shapes to know. So if it hasn't been introduced in class then I wouldn't worry too much about it.
- Sun Nov 17, 2019 7:27 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: HW# 2E.28
- Replies: 1
- Views: 163
HW# 2E.28
Hi could anyone help with approaching this problem
Predict whether each of the following molecules is likely to
be polar or nonpolar: (a) CH3SH (methanethiol, found in breath
odor and skunks); (b) CH3NH2 (methylamine, a drug precursor);
(c) CH3OCH3 (dimethyl ether, used as an aerosol propellant).
Predict whether each of the following molecules is likely to
be polar or nonpolar: (a) CH3SH (methanethiol, found in breath
odor and skunks); (b) CH3NH2 (methylamine, a drug precursor);
(c) CH3OCH3 (dimethyl ether, used as an aerosol propellant).
- Sun Nov 17, 2019 7:16 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Test 2
- Replies: 19
- Views: 831
Re: Test 2
if you're not very sure on whether you can correctly visualize the molecule in your head then its safe to draw the lewis structure for an accurate VSEPR shape
- Sun Oct 27, 2019 6:37 pm
- Forum: Sigma & Pi Bonds
- Topic: Single vs. Double bonds
- Replies: 15
- Views: 1908
Re: Single vs. Double bonds
Double bonds involving carbon are stronger than single bonds and are also shorter. Double and triple covalent bonds are stronger than single covalent bonds.
- Sun Oct 27, 2019 6:30 pm
- Forum: General Science Questions
- Topic: Midterms
- Replies: 22
- Views: 893
Re: Midterms
Midterms are just the prior info given before the test. I believe the finals are cumulative.
- Sun Oct 27, 2019 6:24 pm
- Forum: Properties of Electrons
- Topic: Electron resonance
- Replies: 2
- Views: 94
Re: Electron resonance
Resonance is a mental exercise and method within the Valence Bond Theory of bonding that describes the delocalization of electrons within molecules.
- Sun Oct 27, 2019 6:22 pm
- Forum: Properties of Electrons
- Topic: Electron removal
- Replies: 11
- Views: 386
Re: Electron removal
The increased distance weakens the nuclear attraction to the outer-most electron, and is easier to remove (requires less energy).
- Sun Oct 27, 2019 6:20 pm
- Forum: Octet Exceptions
- Topic: octet rule exception
- Replies: 3
- Views: 142
Re: octet rule exception
Yes it could accommodate more than eight valence electrons by using one or more d orbitals
- Sun Oct 20, 2019 7:19 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Problem 1E.5
- Replies: 2
- Views: 167
Problem 1E.5
Can someone explain part b to me 1E.5 Which of the following statements are true for many-electron atoms? If false, explain why. (a) The effective nuclear charge Zeffe is independent of the number of electrons present in an atom. (b) Electrons in an s-orbital are more effective than those in other o...
- Sun Oct 20, 2019 7:16 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Problem 1E.25
- Replies: 2
- Views: 64
Problem 1E.25
Hi can someone assist me on this
1E.25 Give the notation for the valence-shell configuration
(including the outermost d-electrons) of (a) the alkali metals;
(b) Group 15 elements; (c) Group 5 transition metals; (d) the
“coinage” metals (Cu, Ag, Au).
1E.25 Give the notation for the valence-shell configuration
(including the outermost d-electrons) of (a) the alkali metals;
(b) Group 15 elements; (c) Group 5 transition metals; (d) the
“coinage” metals (Cu, Ag, Au).
- Sun Oct 20, 2019 7:10 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Hund's Rule
- Replies: 3
- Views: 175
Hund's Rule
When writing an electron configuration how does the Hund's rule come in? Is it only when more than one orbital in a subshell is available? Or is it when their spin numbers are paired?
- Sun Oct 20, 2019 7:00 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Problem 1a.11
- Replies: 3
- Views: 141
Problem 1a.11
Hi could someone walk me through this please. 1A.11 In the spectrum of atomic hydrogen, several lines are generally classified together as belonging to a series (for example, Balmer series or Lyman series, as shown in Fig. 1A.10). What is common to the lines within a series that makes grouping them ...
- Sun Oct 20, 2019 6:55 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Advice for studying
- Replies: 92
- Views: 6541
Re: Advice for studying
Something that has been immensely helpful to me is the AAP program. Enrolling in a plf session two times a week has helped me review a lot in addition to the step up program.
- Sun Oct 13, 2019 9:50 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Post Module Calculation
- Replies: 2
- Views: 75
Re: Post Module Calculation
Correction 2 x 10^-11 m
- Sun Oct 13, 2019 9:47 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Post Module Calculation
- Replies: 2
- Views: 75
Re: Post Module Calculation
Use the formula (h/4pi x delta p) and plug in all the values after solving for delta x.
I think the answer is Delta x >= 2 x 10^11 m
I think the answer is Delta x >= 2 x 10^11 m
- Sun Oct 13, 2019 9:37 am
- Forum: Properties of Light
- Topic: de broglies equation
- Replies: 6
- Views: 297
Re: de broglies equation
Also if their is massless particles like photons, I believe we can use c=λν or E=hν. And I think the formula c=λν can be used for objects with a mass you just have to replace the speed of light (c), with velocity
- Sun Oct 13, 2019 9:26 am
- Forum: Properties of Light
- Topic: Question of the Hypothetical Variety (nah not really)
- Replies: 2
- Views: 89
Re: Question of the Hypothetical Variety (nah not really)
I think it's because all electromagnetic radiation, regardless of wavelength or frequency, travels at the speed of light.
- Sun Oct 13, 2019 9:18 am
- Forum: Properties of Electrons
- Topic: Quantum electrons
- Replies: 2
- Views: 201
Quantum electrons
How do I know how to assign quantum numbers to electrons?
- Sun Oct 13, 2019 9:13 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Post Module Problem
- Replies: 1
- Views: 163
Re: Post Module Problem
The size of the atom represents the uncertainty in position. The radius of the atom represents 1/2 of the uncertainty of the position of the electron, the diameter equaling the entire uncertainty. Use this and the mass of an electron and the constant h/4pi to calculate delta-v, or the uncertainty in...
- Sat Oct 05, 2019 6:50 pm
- Forum: Limiting Reactant Calculations
- Topic: Clarifying Limiting Reactants
- Replies: 2
- Views: 129
Re: Clarifying Limiting Reactants
The way I've learned it is to have the balanced chemical equation for the chemical reaction and convert all given information into moles. Then use stoichiometry for each individual reactant to find the mass of product produced.The reactant that has a lesser amount of product is the limiting reagent.
- Sat Oct 05, 2019 6:44 pm
- Forum: SI Units, Unit Conversions
- Topic: Fundamentals E.9
- Replies: 2
- Views: 214
Re: Fundamentals E.9
To find the formula units of the compound I believe you take the amount of sample and divide it by its molar mass in order to get the moles of the sample. To find the formula unit from the compound use Avogadro's constant
= (5.15g/(246.48 g/mol))(6.022x10^23)
= (5.15g/(246.48 g/mol))(6.022x10^23)
- Sat Oct 05, 2019 6:38 pm
- Forum: Significant Figures
- Topic: Next Week's Test 1
- Replies: 9
- Views: 522
Re: Next Week's Test 1
I think the most important info to study for Test 1 would be the Review and fundamentals not so much the sig fig aspect
https://lavelle.chem.ucla.edu/wp-conten ... ciples.pdf
https://lavelle.chem.ucla.edu/wp-conten ... ciples.pdf
- Sat Oct 05, 2019 6:29 pm
- Forum: General Science Questions
- Topic: HW# H.7
- Replies: 1
- Views: 157
HW# H.7
Hi so I'm a little overwhelmed by this question and would like some advice on how to approach H.7 Write a balanced chemical equation for each of the following reactions. (a) Calcium metal reacts with water to produce hydrogen gas and aqueous calcium hydroxide. (b) The reaction of solid sodium oxide,...
- Sat Oct 05, 2019 6:17 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Absorption Spectrum
- Replies: 2
- Views: 214
Re: Absorption Spectrum
I think its because wavelength of light comes from photons with a specific energy released by electrons making transitions between specific energy levels of the atom.When an electron in an atom goes from a higher energy level to a lower energy level, it gives a photon to carry off the extra energy. ...