## Search found 54 matches

Sat Dec 07, 2019 7:43 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: H20
Replies: 4
Views: 94

### H20

Why is H2O a monodentate when it has 2 pairs of lone electrons?
Sat Dec 07, 2019 1:20 pm
Forum: Naming
Topic: Ligands
Replies: 4
Views: 64

### Re: Ligands

^^^Thank you
Sat Dec 07, 2019 1:16 pm
Forum: Naming
Topic: Ligands
Replies: 4
Views: 64

### 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: 288
Views: 37868

### 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: 225

### 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: 111

### 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?
Sat Dec 07, 2019 12:01 pm
Forum: Ionic & Covalent Bonds
Topic: Nonpolar and polar
Replies: 16
Views: 317

### 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: 119

### 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: 37

### 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: 65

### 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: 119

### Re: Sharing resources

Fri Dec 06, 2019 8:50 pm
Forum: Naming
Topic: How to find out the oxidation number?
Replies: 3
Views: 114

### 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: 108

### 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: 135

### 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: 6631

### 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: 4
Views: 187

### 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: 157

### 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.
Wed Dec 04, 2019 8:30 pm
Forum: Student Social/Study Group
Replies: 14
Views: 512

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: 81

### 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: 3
Views: 59

### 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: 122

### 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
Replies: 25
Views: 931

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: 117

### 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: 695

### 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
Replies: 15
Views: 356

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: 234

### 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: 69

### 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
Replies: 92
Views: 2199

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: 43

### 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?
Sun Nov 17, 2019 7:33 pm
Forum: Student Social/Study Group
Topic: Final Jitters
Replies: 288
Views: 37868

### 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: 37

### 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: 46

### 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).
Sun Nov 17, 2019 7:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 19
Views: 374

### 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: 432

### 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: 381

### 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: 52

### 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: 182

### 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: 64

### 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: 45

### 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: 36

### 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).
Sun Oct 20, 2019 7:10 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Hund's Rule
Replies: 3
Views: 74

### 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: 71

### 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
Replies: 92
Views: 2199

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: 46

### 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: 46

### 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
Sun Oct 13, 2019 9:37 am
Forum: Properties of Light
Topic: de broglies equation
Replies: 6
Views: 117

### 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: 23

### 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: 26

### 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: 59

### 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: 63

### 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: 113

### 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)
Sat Oct 05, 2019 6:38 pm
Forum: Significant Figures
Topic: Next Week's Test 1
Replies: 9
Views: 243

### 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
Sat Oct 05, 2019 6:29 pm
Forum: General Science Questions
Topic: HW# H.7
Replies: 1
Views: 95

### 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: 120

### 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. ...