Search found 58 matches

by Dakota Walker 1L
Thu Dec 05, 2019 8:57 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: 9C.5
Replies: 1
Views: 41

Re: 9C.5

The rule is atom with lone pair - spacer atom - spacer atom - atom with lone pair. In CO3- this rule allows for only 2 bonds, and for C2O4, the same applies since you must have atoms in between.
by Dakota Walker 1L
Thu Dec 05, 2019 8:50 am
Forum: Properties & Structures of Inorganic & Organic Bases
Topic: Strength of bases
Replies: 1
Views: 89

Strength of bases

How are you supposed to compare strength of bases?
I know for acids you look at size and charge dispersion, what would you use for bases?
by Dakota Walker 1L
Thu Dec 05, 2019 8:40 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Lone Pairs in this Compound
Replies: 2
Views: 65

Re: Lone Pairs in this Compound

I think the third lone pair can be found on the third nitrogen (the NH).
by Dakota Walker 1L
Thu Dec 05, 2019 8:39 am
Forum: Amphoteric Compounds
Topic: Water
Replies: 1
Views: 32

Re: Water

Water can act as an acid or a base, if it is mixed with an acid, for example HCl +H2O then it will act as a base and form H3O+ and Cl-. If water is mixed with a base such as NH3 +H2O then it will act as an acid and donate a proton forming OH- and NH4+.
by Dakota Walker 1L
Thu Dec 05, 2019 8:35 am
Forum: Polyprotic Acids & Bases
Topic: Chelate/polydentate
Replies: 2
Views: 75

Chelate/polydentate

Is there a difference between chelates and polydentate molecules?
If so how would you define each of them?
by Dakota Walker 1L
Sun Dec 01, 2019 5:00 pm
Forum: Industrial Examples
Topic: Biological examples of co-ordination compounds
Replies: 3
Views: 126

Biological examples of co-ordination compounds

Do we need to know specific examples and how they work for the final?
If so does anyone know which specific molecules we need to memorize?
by Dakota Walker 1L
Sun Dec 01, 2019 4:57 pm
Forum: Naming
Topic: Naming for the final
Replies: 6
Views: 118

Naming for the final

Can someone summarize the general rules for naming we will need for the final?
I don't understand what we do and don't have to memorize/know.
by Dakota Walker 1L
Sun Dec 01, 2019 4:55 pm
Forum: Lewis Acids & Bases
Topic: bronsted vs lewis
Replies: 9
Views: 130

Re: bronsted vs lewis

Lewis acids accept electrons and lewis bases donate electrons.
Bronsted acids donate protons and bronsted bases accept protons.
by Dakota Walker 1L
Sun Dec 01, 2019 4:53 pm
Forum: Bronsted Acids & Bases
Topic: Distinguishing between the different definitions of acids and bases
Replies: 2
Views: 33

Re: Distinguishing between the different definitions of acids and bases

A bronsted base is a proton accepter while a bronsted acid is a proton donor, lewis acids and bases are the same they are just described differently where a lewis acid accepts electrons and a lewis base donates electrons. Arrhenius refers to acids and bases by OH- and H+ concentration so an acid put...
by Dakota Walker 1L
Sun Dec 01, 2019 4:49 pm
Forum: Naming
Topic: Cis & Trans
Replies: 3
Views: 36

Re: Cis & Trans

If you were to include cis or trans in the naming would this just come at the front of the entire name?
by Dakota Walker 1L
Tue Nov 19, 2019 1:28 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: States and Intermolecular forces
Replies: 4
Views: 40

Re: States and Intermolecular forces

Yes solids have the strongest intermolecular forces because molecules are interacting so much that they are stuck together in solid form instead of bouncing off each other and moving far away in gas form.
by Dakota Walker 1L
Tue Nov 19, 2019 1:26 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Pi and Sigma bonds
Replies: 5
Views: 88

Pi and Sigma bonds

Can someone explain any general rules about using pi and sigma bonds? I understand how they overlap either end to end or sideways but do you have to draw out the entire 3D structure to figure this out? Or is there a rule deciding how many pi/sigma bonds are in molecules?
by Dakota Walker 1L
Tue Nov 19, 2019 1:23 am
Forum: Determining Molecular Shape (VSEPR)
Topic: How to know which angles are smaller
Replies: 8
Views: 81

Re: How to know which angles are smaller

Square pyramidal shapes have slightly less than 90 degree angles.
by Dakota Walker 1L
Tue Nov 19, 2019 1:22 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Thiosulfate Ion
Replies: 4
Views: 63

Re: Thiosulfate Ion

There should only be double bonds on 2 of the Oxygen atoms!
by Dakota Walker 1L
Tue Nov 19, 2019 1:18 am
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.1
Replies: 4
Views: 44

Re: 2E.1

Linear models can either have no lone pairs, or 3 or 4 sets of lone pairs. When the 3 or 4 sets of lone pairs are in the same plane they do not bend the bonded atoms and therefore the overall molecule can still have a linear structure.
by Dakota Walker 1L
Tue Nov 19, 2019 12:05 am
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E 19
Replies: 1
Views: 33

2E 19

This Question is: Predict the shapes and estimate the bond angles of (a) the thiosulfate ion, S2O3-2; (b) (CH3)2Be; (c) BH2- ; (d) SnCl2. Does anyone know how you would predict the shape of B?? (CH3)2Be has so many connections should we only predict the shape of the middle atom? Would this be linear...
by Dakota Walker 1L
Wed Nov 13, 2019 7:05 pm
Forum: Dipole Moments
Topic: Do lone pairs repel more?
Replies: 5
Views: 59

Re: Do lone pairs repel more?

Yes, 2 lone electrons will create a balloon of repulsion and push the bonded electrons away from them, because they take up more space compared to bonded electrons.
by Dakota Walker 1L
Wed Nov 13, 2019 7:04 pm
Forum: Dipole Moments
Topic: Textbook question 3F.1
Replies: 5
Views: 73

Re: Textbook question 3F.1

There will be london forces for all molecules, dipole-dipole forces for polar molecules where there is a difference in electronegativity between the atoms or a lone pair on the central atom, there are hydrogen bonds found between H and O, F or N, and there could be ionic bonds between atoms that giv...
by Dakota Walker 1L
Wed Nov 13, 2019 7:00 pm
Forum: Dipole Moments
Topic: 3f.15
Replies: 3
Views: 67

Re: 3f.15

I think AsF3 is a polar molecule because it has a lone pair on the central atom, for this reason it will have a higher boiling point than the non-polar AsF5 molecule.
by Dakota Walker 1L
Wed Nov 13, 2019 6:38 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: intermolecular forces
Replies: 8
Views: 146

Re: intermolecular forces

When googling information about SO2 I found that it was bent, polar and has dipole-dipole interactions. Does anyone know if this is true? And if it is, why is the molecule bent?
by Dakota Walker 1L
Tue Nov 12, 2019 1:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Homework for Week 7
Replies: 5
Views: 65

Re: Homework for Week 7

We're supposed to do the end of chemical bonds and not the start of molecular structure/shape?
by Dakota Walker 1L
Tue Nov 12, 2019 1:24 pm
Forum: Administrative Questions and Class Announcements
Topic: Homework Week 7
Replies: 1
Views: 38

Homework Week 7

Are we doing homework this week on Molecular shape, or still on bonding?
by Dakota Walker 1L
Mon Nov 04, 2019 4:34 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Highly Polarized
Replies: 2
Views: 38

Re: Highly Polarized

Highly polarized means that a bond is getting closer to becoming ionic because it has a large difference in its atom charges, and one is pulling the electrons a lot more closer than the other.
by Dakota Walker 1L
Mon Nov 04, 2019 4:29 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic
Replies: 3
Views: 80

Re: Ionic

Electronegativies will be given if we need to calculate them, otherwise we could just compare them based on periodic trends. The gray area describes polar bonds which I don't think are covered on this midterm.
by Dakota Walker 1L
Mon Nov 04, 2019 4:26 pm
Forum: Quantum Numbers and The H-Atom
Topic: Orbital angular momentum
Replies: 4
Views: 162

Re: Orbital angular momentum

What is the orbital angular momentum equation?
by Dakota Walker 1L
Mon Nov 04, 2019 4:26 pm
Forum: DeBroglie Equation
Topic: de Broglie vs electromagnetic radiation
Replies: 3
Views: 74

Re: de Broglie vs electromagnetic radiation

I think debroglis is used if you want to find wave length and E=hv is used if you have frequency or energy and want to find the missing variable.
by Dakota Walker 1L
Mon Nov 04, 2019 4:16 pm
Forum: Ionic & Covalent Bonds
Topic: Question 3.9 Ground state electron configuration
Replies: 2
Views: 3527

Re: Question 3.9 Ground state electron configuration

You need to find the configurations for the elements with 2 less electrons (2+) so for a it would be the ion that matches [Ar]3d74s2, and for b) it would be the ion that goes with [Ar]3d64s2.
by Dakota Walker 1L
Mon Nov 04, 2019 3:56 pm
Forum: Lewis Structures
Topic: Homework 2C3
Replies: 1
Views: 50

Homework 2C3

This problem asks you to draw lewis structures for:
a) periodate ion, b) hydrogen phosphate ion, c) chloric acid etc.

I was wondering if we need to know what a "periodate ion" is for our midterm/final or if the IO4- would be given?
by Dakota Walker 1L
Tue Oct 29, 2019 10:17 pm
Forum: Lewis Structures
Topic: Formal charge
Replies: 9
Views: 111

Formal charge

When drawing lewis structures do we need to calculate all formal charge options in order to decide how the structure should be drawn? Or can you just draw it based on electrons and guess on the double bond.
by Dakota Walker 1L
Tue Oct 29, 2019 10:01 pm
Forum: Lewis Structures
Topic: If the overall charge of a Lewis Structure is -1, does that mean all the atoms' charges are adding to -1?
Replies: 4
Views: 44

Re: If the overall charge of a Lewis Structure is -1, does that mean all the atoms' charges are adding to -1?

Yes! The molecule will have an overall charge of -1, so each atom will have its own charge (likely -2 and +1) allowing the whole molecule to add to -1.
by Dakota Walker 1L
Tue Oct 29, 2019 9:57 pm
Forum: Lewis Structures
Topic: Drawing lewis structures
Replies: 8
Views: 86

Drawing lewis structures

When drawing lewis structures on tests do you need to angle the bonds in the correct ways or would we get full points for drawing our best guess?
by Dakota Walker 1L
Tue Oct 29, 2019 9:11 pm
Forum: Lewis Structures
Topic: Homework 2A 12
Replies: 3
Views: 66

Homework 2A 12

Which M2+ ions are predicted to have the following ground state configurations? [Ar]3d6, [Kr]4d9, [Ar]3d10 etc.
I don't understand what this question is asking, does anyone know how to go about answering it / what the answer is?
by Dakota Walker 1L
Tue Oct 29, 2019 8:44 pm
Forum: Resonance Structures
Topic: Homework 2C 1
Replies: 3
Views: 54

Homework 2C 1

Which of the following species are radicals? a) NO2-, b) CH3, c) OH, d) HOCO.
Can someone explain how to do this question? And explain what a radical is?
by Dakota Walker 1L
Tue Oct 29, 2019 8:42 pm
Forum: General Science Questions
Topic: Midterm 1
Replies: 2
Views: 80

Midterm 1

Does anyone know what topics are on the midterm?
Is it review of chem, quantum world and bond lengths? Or are bond lengths not on it because we are still reviewing them?
by Dakota Walker 1L
Tue Oct 22, 2019 4:17 pm
Forum: Properties of Electrons
Topic: x,y,z for Electrons
Replies: 10
Views: 141

Re: x,y,z for Electrons

x y z differentiate the spaces electons can go within the P orbital because it has 3 spaces for paired electrons, for the D orbital the letters would be different/longer - I would guess u w x y z but am unsure.
by Dakota Walker 1L
Tue Oct 22, 2019 12:38 pm
Forum: Quantum Numbers and The H-Atom
Topic: 1D.19
Replies: 6
Views: 81

Re: 1D.19

The lettered orbitals are what matters in context, the number "4" for example in 4s or 4p is arbitrary.
by Dakota Walker 1L
Tue Oct 22, 2019 12:19 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals 1D.19
Replies: 3
Views: 81

Re: Orbitals 1D.19

You only look at the lettered sub-shells not the number before, so S will always have 1, P has 3, D has 5 and F has 7 (you know this by drawing out the orbitals to place paired electrons in).
by Dakota Walker 1L
Tue Oct 22, 2019 12:16 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Hw 1B.27
Replies: 3
Views: 88

Re: Hw 1B.27

Does anyone know why the uncertainty in the equation wasn't 10 because 5+5 is 10?
by Dakota Walker 1L
Mon Oct 21, 2019 11:20 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Problem 1E.5
Replies: 2
Views: 40

Re: Problem 1E.5

What does Zeffe mean in this context?
by Dakota Walker 1L
Mon Oct 21, 2019 9:20 pm
Forum: Trends in The Periodic Table
Topic: Isotopes
Replies: 2
Views: 39

Isotopes

Homework problem 1B.3. asks for the protons, neutrons and electrons in Boron-11. I answered that the protons would be 5 (because of the atomic number), the electrons would be 5 to match this, and the neutrons would be 6 so that the mass would add up to 11. Is this right?
by Dakota Walker 1L
Mon Oct 21, 2019 9:15 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 4 homework problems
Replies: 5
Views: 64

Week 4 homework problems

How do we know what homework problems to do each week? Like should we be doing quantum world or chemical bond problems for week 4?
by Dakota Walker 1L
Tue Oct 15, 2019 5:51 pm
Forum: DeBroglie Equation
Topic: Given the energy, calculate the wavelength of y-rays
Replies: 11
Views: 1687

Re: Given the energy, calculate the wavelength of y-rays

also how do you convert the 10^-12 answer into nm
by Dakota Walker 1L
Tue Oct 15, 2019 5:45 pm
Forum: DeBroglie Equation
Topic: Given the energy, calculate the wavelength of y-rays
Replies: 11
Views: 1687

Re: Given the energy, calculate the wavelength of y-rays

How do you get the value for c in this equation?
by Dakota Walker 1L
Sun Oct 13, 2019 5:24 pm
Forum: Properties of Electrons
Topic: Friday Lecture
Replies: 2
Views: 28

Friday Lecture

When he went over the 2 models of electrons orbiting a nucleus, was the only thing you were supposed to take away from that the fact that an open line (electron path) would not work?
I feel like i missed the concept we were meant to learn here does anyone know what it is?
by Dakota Walker 1L
Sun Oct 13, 2019 5:20 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Post Module Assessment Number 20
Replies: 3
Views: 29

Re: Post Module Assessment Number 20

Because hydrogen has one electron for every H atom, the number of excited electrons will be equal to the number of excited hydrogen particles, which in this case is 1 million.
by Dakota Walker 1L
Sun Oct 13, 2019 5:17 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: D.19
Replies: 2
Views: 65

Re: D.19

The 4s orbital is lower in energy therefore it is filled before the higher energy 3d orbital. If you draw it out, you can see that 4s is below 3d and thus would fill up sooner.
by Dakota Walker 1L
Sun Oct 13, 2019 5:14 pm
Forum: Properties of Electrons
Topic: Assessing probablity of finding an electron given distance from nucleus
Replies: 2
Views: 28

Re: Assessing probablity of finding an electron given distance from nucleus

a)The energy of an electron does increase as it gets further away from the nucleus, therefore as it moves from the 1s to the 2p orbital it would experience an energy increase.
b)The value of n also increases as an electron moves away from the nucleus (it goes from 1n to 2n etc).
by Dakota Walker 1L
Sun Oct 13, 2019 5:11 pm
Forum: Properties of Electrons
Topic: Equations for electrons
Replies: 4
Views: 29

Equations for electrons

When calculating properties of electrons are we supposed to use equations that include wavelengths, even though an electron does have properties that make it behave like a photon?
by Dakota Walker 1L
Fri Oct 11, 2019 9:32 am
Forum: Administrative Questions and Class Announcements
Topic: Posting
Replies: 3
Views: 54

Posting

How do you create a new post on this website?
I have figured out how to create a completely new topic, which I am doing right now, and how to reply to previously answered questions, but how do you regularly create a new post/question under a previously existing topic?
by Dakota Walker 1L
Fri Oct 11, 2019 9:31 am
Forum: Properties of Light
Topic: Converting units
Replies: 8
Views: 78

Converting units

If you wanted to convert, for example, 400nm to angstroms, how would you do this?
Angstroms are 10^-10m and nm are 1*10^-9m.
Would you have to convert nm to m first, or how generally would you do this?
by Dakota Walker 1L
Thu Oct 10, 2019 1:54 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity and Dilution
Replies: 10
Views: 3094

Re: Molarity and Dilution

I still don't understand why this isn't a dilution when a 75mL solution was created at first, then this same solution was diluted to get a 125mL solution. In what way would a dilution problem be written differently?
by Dakota Walker 1L
Thu Oct 10, 2019 1:39 pm
Forum: Empirical & Molecular Formulas
Topic: post test problem
Replies: 3
Views: 198

post test problem

In the post module test there was a question asking the following: 339.20 g of Cobalt metal is reacted with Fluorine gas to produce a compound with a mass of 996.08 grams. What is the empirical formula of this new compound? I was wondering if you always apply the law of conservation of mass to these...
by Dakota Walker 1L
Wed Oct 09, 2019 11:53 am
Forum: General Science Questions
Topic: Tests
Replies: 9
Views: 127

Tests

Do we need to memorize all the units and conversions we learnt in class (deci, nano, etc) for the test this week or the midterms in class?
by Dakota Walker 1L
Thu Oct 03, 2019 12:07 pm
Forum: Empirical & Molecular Formulas
Topic: Homework L39
Replies: 5
Views: 76

Re: Homework L39

For Cu the charge would be -2 because you pull up the number from the bottom of the opposite element which in this case is (NO3)2, making the charge of Cu -2.
by Dakota Walker 1L
Thu Oct 03, 2019 12:05 pm
Forum: Balancing Chemical Reactions
Topic: Chemical Principles Section L Question 35
Replies: 2
Views: 62

Re: Chemical Principles Section L Question 35

Fe3Br8 + 4Na2CO3 -> 8NaBr + 2CO2 + 2Fe3O4
by Dakota Walker 1L
Thu Oct 03, 2019 11:54 am
Forum: Molarity, Solutions, Dilutions
Topic: Molarity and Ratios
Replies: 3
Views: 42

Re: Molarity and Ratios

I believe you need a balanced chemical equation to solve this problem? But I am not sure how to exactly calculate the molarity of ions if we don't have their molar ratios.
by Dakota Walker 1L
Tue Oct 01, 2019 10:16 pm
Forum: Molarity, Solutions, Dilutions
Topic: Average molar mass
Replies: 2
Views: 81

Re: Average molar mass

Yes, if you are trying to find the molar mass of an isotope you can ignore the average atomic mass and multiply the atomic mass of the isotope by avogadro's number.
by Dakota Walker 1L
Tue Oct 01, 2019 10:09 pm
Forum: Significant Figures
Topic: Sig Figs in homework problems
Replies: 4
Views: 88

Sig Figs in homework problems

Because there are so many different significant figures that can be used for molar masses, for example Hydrogen could be 1.01, 1.008, etc, how does this work with significant figures? If you use 1.01 can you only use 2 decimal places in your final answer?

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