## Search found 56 matches

Sat Dec 07, 2019 1:31 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: KA1>KA2>KA3
Replies: 2
Views: 44

### KA1>KA2>KA3

I am not sure why this statement is true KA1>KA2>KA3. Please explain why it is harder to lose H+ from negatively charged ions.
Sat Dec 07, 2019 1:23 pm
Forum: Hybridization
Topic: 2sp2 vs sp2
Replies: 3
Views: 79

### Re: 2sp2 vs sp2

The two specifies what row the element is in, so since carbon is in the second row it has the 2 in front of the p. Unless specified, sp^2 can still be the correct hybridization for carbon.
Sat Dec 07, 2019 1:22 pm
Forum: Naming
Topic: Ligands
Replies: 4
Views: 54

### Re: Ligands

They are both chelating ligands because they are complexes that contain a ligand that forms a ring of atoms around a central atom. The ring is formed because 2 electron pairs are donated for bidentate ligands. Polydentate ligands just have to donate more than one electron pair.
Sat Dec 07, 2019 1:19 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Oxidation State
Replies: 1
Views: 33

### Oxidation State

How is oxidation state determined? Please explain this step by step using the heme complex from the practice final problems (Marshmallow) #21, which tells you to find the oxidation state of Iron. Feel free to explain this using other examples as well.
Sat Dec 07, 2019 1:16 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pH and pKA for acids
Replies: 1
Views: 29

### pH and pKA for acids

I am rereading the notes from week 10, lecture 1 and I see if the pH<pKA then the solution is acidic. Is this true all the time because in the example for HA from lecture, the pH is more than pKA since the pH is 6 and the pKA is 4.22, the solution is still labeled as acidic? How is this true?
Fri Dec 06, 2019 6:19 pm
Forum: Naming
Topic: Coordination Number
Replies: 3
Views: 49

### Coordination Number

How is coordination number determined?
Can someone explain this using the following example: [Fe(CN)6]^4-
Fri Dec 06, 2019 6:17 pm
Forum: Hybridization
Topic: 2s for Carbon hybridization
Replies: 3
Views: 53

### 2s for Carbon hybridization

For many examples I am noticing that the hybridization of Carbon begins with 2s instead of just s. For instance, methyl-2-cyanoacrylate has carbons that have C2sp^2 as their hybridization. Can someone explain why it is 2s instead of just s?
Sat Nov 30, 2019 9:53 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted Base and Acid
Replies: 5
Views: 63

### Bronsted Base and Acid

Is a Bronsted base and acid determined only on whether or not a proton is accepted or donated?
Sat Nov 30, 2019 9:15 pm
Forum: Conjugate Acids & Bases
Topic: Product of Acid and Base
Replies: 5
Views: 71

### Product of Acid and Base

Why does the reaction between an acid and a base product salt and water?
Sat Nov 30, 2019 9:09 pm
Forum: Hybridization
Topic: What to consider for hybridization?
Replies: 3
Views: 46

### What to consider for hybridization?

Should I only consider lewis structures and orbitals when determining hybridization?
Sat Nov 30, 2019 9:01 pm
Forum: Amphoteric Compounds
Topic: determining if compounds are acids, bases, or amphoteric
Replies: 3
Views: 49

### Re: determining if compounds are acids, bases, or amphoteric

I would also look at what elements makeup the compound, since the location of the element on the periodic table could provide insight on whether or not the compound is acidic, basic, or both.
Sat Nov 30, 2019 8:50 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: What is this?
Replies: 5
Views: 97

### Re: What is this?

I would review outline 5 on the class website, it details what we need to know regarding coordination compounds, etc.
Sun Nov 24, 2019 5:56 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: AXE
Replies: 6
Views: 154

### Re: AXE

I would also remember to consider that just because molecules have the same AXE, it does not mean they will have the same angles.
Sun Nov 24, 2019 5:54 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarity
Replies: 5
Views: 53

### Polarity

What is the best way to understand polarity and apply it to molecules? Are there any rules I should memorize to be able to identify if the molecule I am looking at is polar or nonpolar? Are there any exceptions to general rules of polarity?
Sun Nov 24, 2019 5:52 pm
Forum: Determining Molecular Shape (VSEPR)
Replies: 4
Views: 46

How do radicals contribute to molecular shape? Do they cause major repulsion?
Sun Nov 24, 2019 5:51 pm
Forum: Sigma & Pi Bonds
Topic: Visualizing this
Replies: 4
Views: 154

### Re: Visualizing this

I base the sigma and pi bonds off of how many bonds are present:
1 bond= sigma
double bound= sigma + pi
triple bond= sigma +2 pi bond
Sun Nov 24, 2019 5:50 pm
Forum: Hybridization
Topic: Hybridization
Replies: 3
Views: 45

### Hybridization

Is hybridization mainly depending on orbitals and the space electrons occupy?
Sat Nov 16, 2019 12:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shape of ClO2+
Replies: 6
Views: 82

### Re: Shape of ClO2+

I think the solutions manual shows the shape and then the shape including all of the electronic densities ( which includes lone pairs). Be sure to read the question carefully and see whether or not the lone pairs should be accounted for when identifying the shape.
Sat Nov 16, 2019 12:45 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: Test 2
Replies: 5
Views: 50

### Re: Test 2

There is not going to be quantum or fundamentals on the exam. It will be the material starting with types of bonds ( eg. London Dispersion) all the way until Monday's lecture on hybridization (Pi and Sigma Bonds).
Sat Nov 16, 2019 12:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone pairs
Replies: 3
Views: 32

### Re: Lone pairs

This is why you may see lone pairs on opposite sides of each other because lone pairs want to be far from each other due to their repulsion. Thus, you may see them on opposite sides of the equatorial axis of a molecule.
Sat Nov 16, 2019 12:41 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 3
Views: 39

### Re: Bond Angles

I would review the concept of repulsion Lavelle talked about in class. He lays out the parts of a molecule that cause repulsion. For instance, a lone pair causes repulsion and can cause two atoms to come closer together. This would decrease the angle between the atoms.
Sat Nov 16, 2019 12:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: T-shape
Replies: 6
Views: 81

### Re: T-shape

T shaped is mentioned in the homework problems for 2E, so I recommend doing those problems and referring to the chart Julia Chang posted which shows how lone pairs can influence the shape. In this case, T shape is created when there are two lone pairs.
Sat Nov 09, 2019 5:39 pm
Forum: SI Units, Unit Conversions
Topic: Memorizing Conversions
Replies: 25
Views: 543

### Re: Memorizing Conversions

In case I forgot how to do a conversion, I use the equation sheet and confirm my answer using KHDUDCM ( King Henry Doesn't Usually Drink Chocolate Milk). This acronym stands for each unit and u is the base unit you convert to a different unit, the number of times you move from U or another base unit...
Sat Nov 09, 2019 5:35 pm
Forum: Lewis Structures
Topic: When to draw Resonance Structures
Replies: 14
Views: 174

### Re: When to draw Resonance Structures

The midterm did say to draw the resonance structure if appropriate, so I think in the future you would have to determine whether or not there is a resonance structure. For instance, if it doesn't matter which oxygen has the double bond and which one has the single bond it may look like you have a re...
Sat Nov 09, 2019 5:31 pm
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 18
Views: 195

### Re: Drawing Lewis Structures

Try to draw the lewis structure where it will be the most stable unless the questions asks you otherwise or to match the charge on the molecule given in the question. Ultimately, make sure you are addressing the question.
Tue Nov 05, 2019 11:04 pm
Forum: DeBroglie Equation
Topic: Dino Nuggets Problem 8b
Replies: 11
Views: 491

### Re: Dino Nuggets Problem 8b

I just realized you would need to calculate velocity by manipulating the equations.
Tue Nov 05, 2019 10:16 pm
Forum: DeBroglie Equation
Topic: Dino Nuggets Problem 8b
Replies: 11
Views: 491

### Re: Dino Nuggets Problem 8b

What is our velocity for our kinetic energy?
Sat Nov 02, 2019 9:15 pm
Forum: Limiting Reactant Calculations
Topic: Test 1 Question
Replies: 5
Views: 248

### Test 1 Question

Here is the question: " If 10.00 g of glucose (C6H12O6) is initially present and 5.00 g of H20 is formed, how much grams of glucose is left over? How many moles of 02 were initially present? (glucose is 180.156 g/mol) I converted water and glucose into moles first, but then I got stuck. What ne...
Sat Nov 02, 2019 9:11 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: delta V. in. Heisenberg questions
Replies: 2
Views: 54

### Re: delta V. in. Heisenberg questions

This is a typo: On the website you can find the typo and the correction: "1B.27
Solution manual states Δv = 5.0 m.s-1
Velocity was given as 5.00 ± 5.0 m.s-1
Therefore Δv = 10.0 m.s-1
With the correction, the final answer is: Δx = 6.7 x 10-37 m"
Sat Nov 02, 2019 9:08 pm
Forum: Ionic & Covalent Bonds
Topic: covalent character
Replies: 3
Views: 40

### Re: covalent character

I believe he was just referring to the the characteristics of a bond being covalent in relation to its partial ionic character and propensity to attract electrons. He did then talk about how bonds could have both ionic and covalent characteristics, where the electronegativity difference determines w...
Sat Nov 02, 2019 9:02 pm
Forum: Lewis Structures
Topic: Dino Nugs 12b
Replies: 5
Views: 72

### Re: Dino Nugs 12b

Does Cl04- not have any resonance structures? I thought it did have resonance, but it makes more sense to me that oxygen has the negative charge because it's more electronegative.
Sat Nov 02, 2019 8:50 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Atoms to Moles
Replies: 7
Views: 240

### Re: Atoms to Moles

The way I convert from moles to atoms is I take avogadro's number and I multiply by the molar amount given/ found, since avogadro's number is equal to one mole. Thus, to convert from atoms to moles you would do the opposite, which is to divide.
Fri Oct 25, 2019 11:06 pm
Forum: Properties of Light
Topic: visible light
Replies: 2
Views: 43

### Re: visible light

I would study that information, I think it would be helpful to know what color has a higher frequency than the other because we did a practice problem in a step-up session that asked to identify the color the frequency we calculated matched.
Fri Oct 25, 2019 11:03 pm
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 2
Views: 34

### Re: Drawing Lewis Structures

In this case I would just count the number of valence electrons for each element and add them like we did in class on Wednesday. There would be no need to subtract or add electrons unless specified.
Fri Oct 25, 2019 11:01 pm
Forum: Lewis Structures
Topic: 2B.3
Replies: 1
Views: 36

### 2B.3

Draw the Lewis structure of (d) BrF3

Why does Br have two extra lone pairs at the top? Is it one of the exceptions to the octet rule?
Fri Oct 25, 2019 11:00 pm
Forum: Lewis Structures
Topic: HW question 2B.3
Replies: 2
Views: 44

### HW question 2B.3

Draw the Lewis structure of (c) SiO2

Why does the lewis structure have double bonds in between Si and Oxygen instead of just single bonds with lone pairs around the oxygen?
Fri Oct 25, 2019 10:53 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 4
Views: 64

### Re: Formal Charge

Formal charge can also help you determine whether or not a certain lewis structure is better than the other if there is more than one way to draw a lewis structure. The more stable the formal charge is, the better the lewis structure is.
Fri Oct 25, 2019 10:51 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Topics
Replies: 5
Views: 75

### Re: Midterm Topics

I think the midterm will cover everything we have learned in class, but it will most likely focus more on the units we studied after the fundamentals since we were already tested on high school chem
Thu Oct 17, 2019 8:23 pm
Forum: Properties of Light
Topic: 1A.5
Replies: 6
Views: 74

### 1A.5

1A.15 states "Arrange the following types of photons of electromagnetic radiation in order of increasing energy: γ-rays, visible light, ultraviolet radiation, microwaves, x-rays." Would I just have to memorize the properties of each type of photons? How else could I solve this problem with...
Thu Oct 17, 2019 8:19 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Drawing Orbitals
Replies: 5
Views: 69

### Re: Drawing Orbitals

He did mention in class that you will not need to know how to draw orbitals, but he said it helps to get a general idea of how the orbitals look to clarify certain features of the orbitals. For instance, the principal and orbital angular momentum quantum numbers. If you are a more visual learner, I ...
Thu Oct 17, 2019 8:15 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Replies: 92
Views: 1851

I highly highly recommend going to the Step Up sessions. I feel like they review the material in class really well, so if I am lost I can just ask any questions during the review. They also provide some practice problems for extra support. I think this is a great way to refresh topics and see what t...
Thu Oct 17, 2019 8:12 pm
Forum: Properties of Electrons
Topic: 1D.15
Replies: 2
Views: 54

### 1D.15

1D.15 states "What are the principal and orbital angular momentum quantum numbers for each of the following orbitals: (a) 6p; (b) 3d; (c) 2p; (d) 5f? I understand that the principal number is just the number given, but can someone explain how to find the orbital angular momentum number?
Thu Oct 17, 2019 8:07 pm
Forum: Properties of Electrons
Topic: x,y,z for Electrons
Replies: 10
Views: 141

### x,y,z for Electrons

In class we discussed the example of px,py,pz in relation to electrons. Does x,y,z represent the coordinate plane? Can someone explain the role of x,y,z?
Fri Oct 11, 2019 11:01 pm
Forum: Properties of Electrons
Topic: Electron Energy Levels
Replies: 8
Views: 76

### Re: Electron Energy Levels

Does anyone know if the energy levels correspond to the electron shells of a particular atom?
Fri Oct 11, 2019 10:59 pm
Forum: Trends in The Periodic Table
Topic: Element Names
Replies: 8
Views: 608

### Re: Element Names

The periodic table is not color coded on tests. I recommend using the periodic table from the chem 14 A website when doing your homework. This will help you become more accustomed to using the same periodic table that is used on tests and will make taking the tests seem more familiar.
Fri Oct 11, 2019 10:56 pm
Forum: Molarity, Solutions, Dilutions
Topic: M1V1=M2V2
Replies: 11
Views: 6562

### Re: M1V1=M2V2

During one of the step up sessions, the UA said to use M1V1=M2V2 whenever a dilution is mentioned. However, when you can't identify a dilution is occurring you most likely have to use M= m/v. This may not always be the case, but this is how I would think of it in simplest terms.
Fri Oct 11, 2019 10:51 pm
Forum: Significant Figures
Topic: Sig Figs
Replies: 5
Views: 195

### Re: Sig Figs

I recommend rounding to the correct number of sig figs at the end for your answer, but during your work I suggest not rounding to the correct number of sig figs. This aids in reducing any rounding error in the end. Also, be sure your answer in sig figs matches the smallest sig fig provided in the qu...
Fri Oct 11, 2019 10:47 pm
Forum: Empirical & Molecular Formulas
Topic: How to format formulas
Replies: 4
Views: 196

### Re: How to format formulas

I also heard that formulas can be formatted with C and H first and then every other element after is placed alphabetically. Is this the hill system? Does this always work?
Wed Oct 09, 2019 9:26 pm
Forum: Empirical & Molecular Formulas
Topic: How to format formulas
Replies: 4
Views: 196

### How to format formulas

When told to find the empirical or molecular formula, how do I know what order to put the elements in? Is there a specific order or rules I should follow?
Thu Oct 03, 2019 3:14 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Fundamental E
Replies: 2
Views: 105

### Fundamental E

Self Test E.1B states, "A double espresso contains 3.14 mol H2O. What is the number of H atoms present in the espresso?" Based on the result, I was confused as to why oxygen was not subtracted from the number of H atoms. Anyone know why oxygen is not subtracted from the total number of H a...
Thu Oct 03, 2019 3:03 pm
Forum: Significant Figures
Topic: Sig Fig Rules
Replies: 7
Views: 96

### Re: Sig Fig Rules

For rounding your answer, I would wait to round until you get your final answer to ensure a more precise answer. Also, for sig figs you should look for the smallest sig fig value given in the problem. For instance, if the problem gave you a value with 5 sig figs and a value with 2 sig figs, your ans...
Thu Oct 03, 2019 3:00 pm
Forum: Significant Figures
Topic: Sig Figs in an Answer
Replies: 3
Views: 73

### Re: Sig Figs in an Answer

I was always taught to go by the value with the least sig figs. So if one of the values in the problem was 4 sig figs and the other value was 3 sig figs, you would make your answer have 3 sig figs. Hope this helped! Also, if you need additional help with sig figs I recommend looking up sig fig works...
Thu Oct 03, 2019 2:53 pm
Forum: Significant Figures
Topic: Sig Fig Rules
Replies: 3
Views: 93

### Re: Sig Fig Rules

It has also been some time since I have reviewed sig figs and I recommend that you look up worksheets online to practice the common sig fig rules. Your sig figs in your final answer should match the smallest sig fig value in the problem, but be sure to remember the sig fig rules. For instance, revie...
Wed Oct 02, 2019 11:18 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Fundamental E
Replies: 2
Views: 81

### Fundamental E

In Fundamental E, Example E.2 states "Fluorine gas is so reactive that it reacts explosively with almost every other element. If you are working with fluorine and making quantitative observations, it is very important to know how much material you have. Calculate (a) the amount of F2 and (b) th...
Wed Oct 02, 2019 11:05 pm
Forum: Administrative Questions and Class Announcements
Topic: Tips for Tests [ENDORSED]
Replies: 4
Views: 118

### Re: Tips for Tests[ENDORSED]

I spoke with one of the UA's and went to their Step-Up session on Tuesday and they really recommended taking advantage of the resources available. For instance, the Step-Up session really helped me solidify my confidence in certain skills and identify areas I am weaker in. They gave us a bunch of pr...
Mon Sep 30, 2019 9:19 pm
Forum: Balancing Chemical Reactions
Topic: Fundamental L
Replies: 2
Views: 156

### Fundamental L

I am having a hard time with Self Test L.2A in Fundamental L. The problem states, " Calculate the mass of potassium metal needed to react with 0.450 g of hydrogen gas to produce solid potassium hydride, KH." Do I have to first create the balanced chemical equation? If so, how do I do this ...