Search found 58 matches

Thu Dec 05, 2019 1:21 am
Forum: Lewis Acids & Bases
Topic: HW #6.13
Replies: 1
Views: 48

HW #6.13

Is the first part of the answer: no? For the second part of the question, why isn't boric acid a Lewis base? I thought since the oxygens have multiple unpaired electrons present, it would be a Lewis base, but the answer is Lewis acid.
Thu Dec 05, 2019 1:18 am
Forum: Conjugate Acids & Bases
Topic: HW 6D #11
Replies: 1
Views: 34

HW 6D #11

For this problem, would the answer be just NH4Br---> NH4+ Br-? or would it include H2O as a base? so it looks like NH4Br + H2O---> NH4+H3O+ Br- ? How would I approach the second part of the problem?
Thu Dec 05, 2019 1:11 am
Forum: Lewis Acids & Bases
Topic: HW 6.B #9
Replies: 1
Views: 44

HW 6.B #9

I thought for this problem you had to plug in 1.5 into -log(HA) to find the pOH,, but I'm not sure if that's right... How would I approach this problem?
Thu Dec 05, 2019 1:09 am
Forum: Lewis Acids & Bases
Topic: HW 6.B #3
Replies: 1
Views: 26

HW 6.B #3

I'm not sure which formula to use for this problem and how I would overall just approach this problem... Also, are we expected to be able to solve using numerical values in this problem on the final? or can we just set up the equation but not solve for it?
Thu Dec 05, 2019 1:02 am
Forum: Lewis Acids & Bases
Topic: HW 6.A.1 #9
Replies: 1
Views: 29

HW 6.A.1 #9

How do you know which is the acid and base in these equations? How would I approach this problem?
Fri Nov 29, 2019 2:28 am
Forum: Lewis Acids & Bases
Topic: Lecture Question
Replies: 2
Views: 38

Lecture Question

Why is trichloroacetic acid a stronger acid than acetic acid again?
Fri Nov 29, 2019 2:16 am
Forum: Lewis Acids & Bases
Topic: Bonds and pH
Replies: 4
Views: 35

Bonds and pH

Why is it that short strong bonds are less acidic and long weaker bonds have more acidic components?
Fri Nov 29, 2019 2:12 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 3
Views: 31

Ligands

Is there ever an instance when ligands don't have a lone pair? If the central element does not have a lone pair does that mean it is not a ligand? If so, what else can it be?
Fri Nov 29, 2019 2:09 am
Forum: Lewis Acids & Bases
Topic: Weak and Strong Acids and Bases
Replies: 3
Views: 29

Weak and Strong Acids and Bases

How do I determine whether an acid or base is strong or weak? Is it based on if it is a metal or non-metal? Or does it depend on the intermolecular forces or charges?
Fri Nov 29, 2019 2:07 am
Forum: Amphoteric Compounds
Topic: Amphoteric Examples
Replies: 3
Views: 48

Amphoteric Examples

What are some examples of amphoteric compounds and do they react with water to either form a strong base or acid?
Fri Nov 29, 2019 2:05 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Compound Naming
Replies: 1
Views: 26

Compound Naming

How would you name K4 [Ni(N)4]? Which is the best way to name compounds? I still have trouble naming compounds...
Mon Nov 18, 2019 4:44 pm
Forum: Sigma & Pi Bonds
Topic: E Density
Replies: 1
Views: 44

E Density

How is electron density related to calculating bonds?
Mon Nov 18, 2019 4:44 pm
Forum: Ionic & Covalent Bonds
Replies: 1
Views: 63

How do you calculate a bond angle when there is a radical on an element?
Mon Nov 18, 2019 4:41 pm
Forum: Ionic & Covalent Bonds
Topic: Bond Angles Test 2
Replies: 2
Views: 59

Bond Angles Test 2

How do we know when a certain bond angle is 107 degrees? I know for tetrahedrals with lone pairs, they are usually less than 109.5 degrees, but are we expected to know the exact degrees that's a little less than 109.5 degrees?
Mon Nov 18, 2019 4:30 pm
Forum: Lewis Structures
Topic: HW #2.27
Replies: 1
Views: 65

HW #2.27

Why is CH2(2-) the least strongest HCH bond? I thought because it was a tetrahedral with two lone pairs and two bonds, it would be a linear bond angle of 180 degrees.
Mon Nov 18, 2019 3:28 pm
Forum: Lewis Structures
Topic: HW 2E #13 A
Replies: 1
Views: 49

HW 2E #13 A

Is there a difference between a linear-linear and a trigonal bipyramidal- linear, or are they considered the same linear? I got linear for this question as an answer because there were 2 bonds and three lone pairs on the central atom which is a linear.
Thu Nov 14, 2019 12:04 am
Forum: Ionic & Covalent Bonds
Topic: HW 3F #19
Replies: 1
Views: 54

HW 3F #19

For b, how would you determine the vapor pressure? Does it still depend on whichever molecule has the stronger IMF forces?
Wed Nov 13, 2019 10:01 pm
Forum: Ionic & Covalent Bonds
Topic: HW 2D #3
Replies: 2
Views: 44

Re: HW 2D #3

How do we determine the electronegativity difference without having the actual values to determine the difference?
Wed Nov 13, 2019 9:59 pm
Forum: Ionic & Covalent Bonds
Topic: HW #2.25
Replies: 2
Views: 53

HW #2.25

Is the answer for a) H3CNH2 and for b) PF in PF3? I chose H3CNH2 because HCN will have a triple bond, therefore a shorter bond. And for b, I chose PF bond because bond distances increase with atomic size. Since N is a smaller atom than P, I NF3 will have shorter bond distances... Is my reasoning cor...
Wed Nov 13, 2019 8:55 pm
Forum: Ionic & Covalent Bonds
Topic: 2D #11
Replies: 3
Views: 47

2D #11

What's the difference and similarities between polarizing power and polarizability? I thought they were the same thing...
Wed Nov 13, 2019 8:51 pm
Forum: Ionic & Covalent Bonds
Topic: HW 2D #9
Replies: 2
Views: 65

HW 2D #9

For this question, I measured their electronegativities on the chart and got the right answer for the increasing polarizing power. Is there a correlation between electronegativity and polarizing power? The answer key said that it had to do with the radius in that the smaller, highly charged cations ...
Wed Nov 13, 2019 8:41 pm
Forum: Ionic & Covalent Bonds
Topic: Electronegativity
Replies: 7
Views: 100

Electronegativity

Are we given an electronegativity chart for Test 2 to compare electronegativity difference?
Wed Nov 13, 2019 8:31 pm
Forum: Ionic & Covalent Bonds
Topic: HW 2D #5
Replies: 2
Views: 39

HW 2D #5

I know that electronegativity decreases down a period and group. However, for B, since C and F are closer together, wouldn't it have similar electronegative values? So, then it would not be CF4 because the difference is smaller, but the answer is CF4 and not CH4.
Wed Nov 13, 2019 8:29 pm
Forum: Ionic & Covalent Bonds
Topic: HW 2D #3
Replies: 2
Views: 44

HW 2D #3

Is the answer BaBr2 because Ba is more of a heavier alkali metal that's placed lower in the periodic table, so it would be more ionic?
Thu Nov 07, 2019 8:03 pm
Forum: Einstein Equation
Topic: Wavelength and KE
Replies: 5
Views: 174

Wavelength and KE

How do we find wavelength when we're given the kinetic energy in Joules?
Thu Nov 07, 2019 7:56 pm
Forum: Lewis Acids & Bases
Topic: Acid Base
Replies: 1
Views: 35

Acid Base

Are Acids and Base equations always in the form: acid+ base= complex?
Thu Nov 07, 2019 7:53 pm
Forum: Lewis Structures
Topic: Oxygen
Replies: 8
Views: 94

Oxygen

Why does Oxygen have a low first ionization energy?
Thu Nov 07, 2019 7:42 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rhydberg Equations
Replies: 1
Views: 108

Rhydberg Equations

What's the difference between using R(1/n(1)^2- 1/n(2)^2) and -hR/n^2?
Thu Nov 07, 2019 7:40 pm
Forum: Properties of Light
Topic: Work Function
Replies: 2
Views: 129

Work Function

Can I ever use work function as the total energy? For example, can I substitute the work function number for E in the formula: wavelength= hc/E ?
Sun Nov 03, 2019 3:16 pm
Forum: Formal Charge and Oxidation Numbers
Topic: En
Replies: 3
Views: 53

En

When do we get to use the formula: En= -(hR)/ n^2?
Sun Nov 03, 2019 3:13 pm
Forum: Lewis Structures
Topic: Limiting Reactants
Replies: 3
Views: 34

Limiting Reactants

In a problem, when we find the limiting reactant and convert it to grams, is that the amount of how much is produced as a result?
Sun Nov 03, 2019 3:10 pm
Forum: Einstein Equation
Topic: eV
Replies: 4
Views: 186

eV

What does the M stand for when it says 5.4 MeV?
Sun Nov 03, 2019 3:09 pm
Forum: Ionic & Covalent Bonds
Topic: Electron Configuration
Replies: 7
Views: 88

Electron Configuration

If there's a charge on an element, do we always try to move the electrons to complete an orbital or at least make it a half-filled orbital?
Sun Nov 03, 2019 3:07 pm
Forum: Properties of Light
Topic: De Broglie
Replies: 3
Views: 68

De Broglie

Which would have a faster speed?
An electron or proton according to De Broglie's formula?
Fri Oct 25, 2019 5:10 pm
Forum: Lewis Structures
Topic: Steps to drawing a structure
Replies: 5
Views: 64

Re: Steps to drawing a structure

This is because the least electronegative element is able to share more electrons when compared to a more electronegative element. This also may be because less electronegative atoms tend to have a lower number of electrons in the valence shell, so it is easier to add more electrons into its valence...
Fri Oct 25, 2019 5:06 pm
Forum: Properties of Electrons
Topic: 1E1
Replies: 2
Views: 50

Re: 1E1

Since the orbital is going from a lower to higher energy level, the energy of the electron will increase. Energy is a function of n, so n is increased from 1 to 2.
Fri Oct 25, 2019 4:54 pm
Forum: Trends in The Periodic Table
Topic: Electronegativity
Replies: 3
Views: 41

Re: Electronegativity

Atoms with more protons tend to have higher electronegativity because it depends on the atomic number. Higher electronegativity means that electrons are pulled stronger towards itself. Therefore, if the positive nuclear charge is higher, more electrons are pulled closer.
Fri Oct 25, 2019 4:50 pm
Forum: Lewis Structures
Topic: Transition Elements
Replies: 2
Views: 59

Re: Transition Elements

Most transition metals have a valence shell of 2 electrons. This is because most of the elements have a charge of 2+. I assume that if it were to have a different charge, then it would be a different number of electrons according to the charge number.
Fri Oct 25, 2019 4:44 pm
Forum: Octet Exceptions
Topic: Expanded Valence Shells
Replies: 4
Views: 46

Re: Expanded Valence Shells

I wouldn't necessarily say that those elements listed above are the only elements that have expanded valence shells, but those are some widely known examples. When you combine those elements into compounds such as phosphorus pentaflouride, then it is an expanded valence shell since the phosphorus ha...
Fri Oct 25, 2019 4:38 pm
Forum: Ionic & Covalent Bonds
Topic: ground-state configuration of ions
Replies: 4
Views: 48

Re: ground-state configuration of ions

The answer you have [Ar] 3d^10 4s^1 is for Cu, not Cu+. Because the element has become more positive, this means that the electron was removed. Therefore, it would look like [Ar] 3d^10 4s^0 which is [Ar] 3d^10.
Fri Oct 25, 2019 4:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Resonance Delocalization
Replies: 5
Views: 53

Resonance Delocalization

Can someone explain how delocalization works in resonance structures? I was still unclear after lecture.
Fri Oct 25, 2019 4:20 pm
Forum: Lewis Structures
Topic: Single or Double Bonds
Replies: 4
Views: 57

Re: Single or Double Bonds

You use a double bond according to the octet rule where you want the middle element to have a full valence shell of eight electrons.
Mon Oct 14, 2019 10:36 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: HW Question 1.D.13
Replies: 3
Views: 72

HW Question 1.D.13

I get the rest of the parts for this question except A. What is the question asking and why is there 7?
Mon Oct 14, 2019 10:35 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: HW Question 1.B.25
Replies: 3
Views: 59

HW Question 1.B.25

For this problem, I got delta p as greater than or equal to 1.51*10^-25. However, when I try to find delta v, the solution manual states to multiply by 1/2, so it looks like this: .5((1.5*10^-34)/(9.1*10^-31)(350*10^-12))= 1.65*10^5 m/s. Again, why would you multiply that by .5? Isn't the original f...
Mon Oct 14, 2019 10:31 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: HW Question 1.B.27
Replies: 2
Views: 33

HW Question 1.B.27

So for this problem I got the answer to be 8.28*10^-36 m but the answer key replaces h with 1.054*10^-34. Is this a mistake or am I just doing the problem wrong?
Mon Oct 14, 2019 10:29 pm
Forum: Properties of Light
Topic: HW Question 1.B.19
Replies: 2
Views: 25

HW Question 1.B.19

I know for photo-ejection you use the formula Ek= .5m(e)v^2, but how would you approach this problem? Also, when do you use the de Broglie relation?
Mon Oct 14, 2019 10:28 pm
Forum: DeBroglie Equation
Topic: HW Question 1.B.15
Replies: 3
Views: 45

HW Question 1.B.15

I got the velocity for this problem which was 3,600,000 m/s but I can't seem to find the mass for this problem. I know you use wavelength= h/mv but how do you get the mass?
Wed Oct 09, 2019 7:50 pm
Forum: Properties of Light
Topic: Atomic Spectra
Replies: 7
Views: 96

Atomic Spectra

I just want a couple of clarifications:
1. Biggest gap/ difference in energy levels results in the UV region, Lyman Series?
2. Short gaps/ difference in energy levels usually result in the infrared, visible region called the Balmer Series?
Wed Oct 09, 2019 7:41 pm
Forum: Properties of Light
Topic: Photoelectric Effect
Replies: 3
Views: 76

Photoelectric Effect

Can someone explain the photoelectric effect? More specifically, what the work function is and how electrons are removed.
Wed Oct 09, 2019 7:36 pm
Forum: Quantum Numbers and The H-Atom
Topic: Frequency
Replies: 15
Views: 255

Frequency

What's the relationship between frequency and difference in energy levels? Do they both increase, decrease, or either one increases or decreases?
Wed Oct 09, 2019 7:25 pm
Forum: Properties of Light
Topic: Formulas
Replies: 2
Views: 48

Formulas

I can't seem to know when to use the H-atom spectrum formula and the Rydberg equation, since they both include the final and initial energy levels. For example, I used the H-atom spectrum for question #1A. 13, but you're supposed to use the Rydberg equation instead...
Wed Oct 09, 2019 7:20 pm
Forum: SI Units, Unit Conversions
Topic: Test 1_Supplies [ENDORSED]
Replies: 5
Views: 135

Re: Test 1_Supplies[ENDORSED]

no, the TA provides you with a periodic table :)
Wed Oct 09, 2019 7:19 pm
Forum: Properties of Light
Topic: HW Question #1A.15
Replies: 6
Views: 65

HW Question #1A.15

How do you know that n1 level is equal to the Lyman series and why can't n2 be the Lyman series? How do you determine which is final and initial energy level?
Wed Oct 02, 2019 9:22 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Chemical Reaction
Replies: 6
Views: 112

Re: Balancing Chemical Reaction

When it comes to combustion questions, the set up for it is usually like this: CxHy +O2---> CO2+H2O, where the x and y are variables. So in this case, you would replace the x and y as 4 and 10, respectively. I balanced the equation and I got this: 4C4H10+26O2---> 16CO2+20H2O. In order to find the ne...
Wed Oct 02, 2019 9:10 pm
Forum: Limiting Reactant Calculations
Topic: Fundamentals Homework Problem M11
Replies: 3
Views: 93

Re: Fundamentals Homework Problem M11

So from part a, we know that there are 4.47 grams of O2. We then take 5.77g of O2- 4.47g O2 to get the excess amount of O2. Then, we get 1.30 grams of O2 and divide that by the molar mass of oxygen; next, you multiply that by the ratio of P4O10 to O2 in the second equation (1 mol P4O10: 2 mol O2) [t...
Wed Oct 02, 2019 4:52 pm
Forum: Significant Figures
Topic: Rounding Sig Figs
Replies: 4
Views: 69

Re: Rounding Sig Figs

When you're solving a problem, it's best to use the exact numbers with all of the decimals. This way, it gives you the closest number as possible to the correct answer. I recommend rounding the number to the correct amount of sigfigs in the end rather than while you're solving the problem. Also, if ...
Wed Oct 02, 2019 1:00 am
Forum: Accuracy, Precision, Mole, Other Definitions
Replies: 12
Views: 405