Search found 33 matches

by Noah Carey 1G
Sun Jun 10, 2018 8:03 am
Forum: Amphoteric Compounds
Topic: As2O3
Replies: 4
Views: 249

Re: As2O3

In order for it to be amphoteric, it means that the oxide can react either with acid or base. In the case of As2O3 we have the reaction with acid: As2O3 + 6HCl --> 2AsCl3 + 3H2O, and reaction with base NaOH + As2O3 + 3H2O --> 2Na[As(OH)4]. It also applies to Bi2O3. Okay this was the answer I was ex...
by Noah Carey 1G
Sat Jun 09, 2018 9:46 am
Forum: Amphoteric Compounds
Topic: As2O3
Replies: 4
Views: 249

As2O3

How do we determine that As2O3 is amphoteric? I understand that it has acidic and basic characters, but how do I actually figure this out for this compound?
by Noah Carey 1G
Sat Jun 09, 2018 8:04 am
Forum: Bronsted Acids & Bases
Topic: J13
Replies: 1
Views: 178

J13

I understand part a and b of J13 where you calculate the empirical molecular formulas. I have some questions about part c. 1. Will we just be expected to know on a test that the formula C2H2O4 corresponds to (COOH)2? 2. I suppose in the overall equation the reason there are two sodium atoms attached...
by Noah Carey 1G
Fri Jun 08, 2018 7:26 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: ethylenediaminetetraacetato (edta)
Replies: 6
Views: 251

ethylenediaminetetraacetato (edta)

Why is ethylenediaminetetraacetato (edta) not octadentate? There are two additional Oxygen atoms that have double bonds and therefore two lone pairs each. These pairs do not interact with the metal. Is it because the shape can't reach those two Oxygen atoms? Oxygen atoms with a formal charge of 0 ca...
by Noah Carey 1G
Fri Jun 01, 2018 11:31 am
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.25 a
Replies: 2
Views: 96

4.25 a

This problem asks to predict whether CH2Cl2 is polar or nonpolar. Can't the dipole moments of CH2Cl2 cancel out when H is across from H and Cl is across from Cl? Why do you assume H is across from Cl?
by Noah Carey 1G
Fri Jun 01, 2018 11:08 am
Forum: Determining Molecular Shape (VSEPR)
Topic: No central atom
Replies: 1
Views: 75

No central atom

So when we draw up a Lewis structure for a molecule with no central atom are we unable to use the VSEPR notation (AXE)?
by Noah Carey 1G
Fri Jun 01, 2018 10:53 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Atoms with Resonance vs Atoms without
Replies: 1
Views: 73

Re: Atoms with Resonance vs Atoms without

In the VSEPR model, all bonds are treated as equivalent. Resonance doesn't play a role in determining the molecular shape. Just look at the number of bonding pairs and lone pairs to determine the shape of the molecule. This is my understanding and I hope it helps.
by Noah Carey 1G
Wed May 23, 2018 6:37 pm
Forum: Octet Exceptions
Topic: Radicals
Replies: 2
Views: 231

Radicals

When drawing Lewis structures, does the radical go on the most or least electronegative atom? What is more important in determining which atom it goes on, formal charge or electronegativity?
by Noah Carey 1G
Tue May 22, 2018 9:31 pm
Forum: Ionic & Covalent Bonds
Topic: 3.27 part C
Replies: 1
Views: 67

Re: 3.27 part C

The roman numeral 4 tells you that there is a +4 charge on Manganese. You can now finish solving the problem like the other ones in 3.27. If Mn has a +4 charge and O has a -2 charge (assumed because it requires 2 electrons to reach the nearest noble gas configuration), to balance the compound you ne...
by Noah Carey 1G
Tue May 22, 2018 9:18 pm
Forum: Dipole Moments
Topic: Do all covalent bonds have dipole nature?
Replies: 1
Views: 109

Do all covalent bonds have dipole nature?

Do all covalent bonds have dipole nature or are some covalent bonds, like C-H, so similar in electronegativity that they do not have any dipole nature? Where is the cut off if this is the case?
by Noah Carey 1G
Tue May 15, 2018 10:12 pm
Forum: Formal Charge and Oxidation Numbers
Topic: 3.67 part b
Replies: 1
Views: 105

3.67 part b

Why is ClO2 not more stable with a double bond on O and only 1 electron on Cl? The formal charge of the oxygen will turn to 0. Is it not more stable because this will make Cl's formal charge higher?
by Noah Carey 1G
Tue May 15, 2018 9:44 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Reducing formal charge number
Replies: 3
Views: 160

Reducing formal charge number

I understand how to calculate formal charges. What are the methods you can use to reduce them? I should be checking formal charges on every problem I do, correct?
by Noah Carey 1G
Tue May 15, 2018 9:26 pm
Forum: Resonance Structures
Topic: 3.59 part c resonance structure? [ENDORSED]
Replies: 3
Views: 181

3.59 part c resonance structure? [ENDORSED]

I'm confused about resonance structures. In part c of 3.59, should chlorine nitrate ClONO2 have a resonance structure because the double bond with oxygen can be on either O of NO2?
by Noah Carey 1G
Tue May 15, 2018 2:19 pm
Forum: Formal Charge and Oxidation Numbers
Topic: 3.59 [ENDORSED]
Replies: 1
Views: 216

3.59 [ENDORSED]

In chlorine monoxide ClO, when Cl has the radical, the formal charge of Cl is +1 and the formal charge of O is -1. Right? If O is given the radical then the formal charges are 0. Why does Cl have the radical?
by Noah Carey 1G
Sun May 13, 2018 11:52 pm
Forum: Lewis Structures
Topic: Dots or lines [ENDORSED]
Replies: 5
Views: 185

Dots or lines [ENDORSED]

Instead of drawing two dots, my TA saved time by drawing lines which represent two electrons around the element while working through examples in discussion. Can I do this on a test and not be marked down?
by Noah Carey 1G
Wed May 09, 2018 9:28 pm
Forum: Empirical & Molecular Formulas
Topic: Question 3 on midterm [ENDORSED]
Replies: 8
Views: 454

Re: Question 3 on midterm [ENDORSED]

So i assumed oxygen was present in the compound as well, so I started solving for oxygen. I took each of the masses of the products, divided by the molar mass of that product so I could get the moles, then I used another conversion factor (mole of one element/the mole of each product) to get the mo...
by Noah Carey 1G
Wed May 09, 2018 8:21 pm
Forum: Empirical & Molecular Formulas
Topic: Question 3 on midterm [ENDORSED]
Replies: 8
Views: 454

Question 3 on midterm [ENDORSED]

Why were we expected to know the makeup of nicotine? Every empirical and molecular formula problem we've seen in all the practice examples and everything we've covered in class included the elements Hydrogen and Oxygen in the makeup of the compound that underwent combustion. In this question you had...
by Noah Carey 1G
Tue May 08, 2018 12:35 pm
Forum: Trends in The Periodic Table
Topic: Octets and ionization energy
Replies: 2
Views: 159

Octets and ionization energy

Can someone explain to me how I can use “octets” to figure out which ionization energy is higher? Why is Oxygen’s ionization energy lower than Nitrogen’s?
by Noah Carey 1G
Sat May 05, 2018 1:40 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration Exceptions
Replies: 3
Views: 122

Re: Electron Configuration Exceptions

I don't believe all the elements in the column below the chromium and copper exceptions follow the same pattern because the electron configuration for Tungsten, an element two periods below Chromium, is [Xe] 4f14 5d4 6s2? Does anyone know why Tungsten does not follow the exception, but in the same p...
by Noah Carey 1G
Wed May 02, 2018 8:36 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Homework 2.43
Replies: 2
Views: 107

Homework 2.43

I thought Tungsten would follow the same rule as Chromium where the s orbital would only have 1 electron and the d orbital would have 5. Why is this not true? Does the rule stop applying after molybdenum and silver in the fifth period?
by Noah Carey 1G
Wed May 02, 2018 6:46 pm
Forum: Quantum Numbers and The H-Atom
Topic: 2.17 homework problem
Replies: 2
Views: 115

2.17 homework problem

I don't understand why we don't count other orbitals when finding the number of orbitals inside of a sub shell. For part b in 2.17, l=2 so we know that it goes to the d orbital which has 5 spaces to fill. And the answer is 5 orbitals. But what about the s orbital and p orbital that comes before it? ...
by Noah Carey 1G
Sat Apr 28, 2018 10:09 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodal Planes [ENDORSED]
Replies: 6
Views: 204

Re: Nodal Planes [ENDORSED]

How would the presence or absence of a nodal plane influence the electron configuration? Does that mean that the electrons are more evenly distributed in an orbital with nodal planes than in one without nodal planes? The p-, d-, f- orbitals all have nodal planes and non-symmetric electron distribut...
by Noah Carey 1G
Sat Apr 28, 2018 10:02 pm
Forum: Properties of Electrons
Topic: Hydrogen Levels and Energy [ENDORSED]
Replies: 3
Views: 187

Re: Hydrogen Levels and Energy [ENDORSED]

Electrons in hydrogen in lower n-levels have lower energy because they are closer to their attractor, a positively charged nucleus which contains protons and therefore are more satisfied and using less energy. For the Lyman series which includes ultraviolet light the lower energy level is n=1. I'm n...
by Noah Carey 1G
Tue Apr 24, 2018 6:26 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra Post Module #29 [ENDORSED]
Replies: 3
Views: 207

Re: Atomic Spectra Post Module #29 [ENDORSED]

If you divide the 11 Joules of energy by the amount of energy per photon you calculated in the first step, you will get the number of photons of infrared radiation generated.
by Noah Carey 1G
Sat Apr 21, 2018 8:44 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Discrepancy in Rydberg equation [ENDORSED]
Replies: 1
Views: 81

Discrepancy in Rydberg equation [ENDORSED]

At the end of the post module for atomic spectra I understand that when deriving the equation you end up with -R[1/n1^(2)-1/n2^(2)]. Why does the solutions manual under problem 1.15 have the equation listed R[1/n1^(2)-1/n2^(2)] with no negative out in front? Bonus question: is there a way to do 1.15...
by Noah Carey 1G
Sat Apr 21, 2018 7:09 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Baseball through sensors experiment [ENDORSED]
Replies: 5
Views: 224

Re: Baseball through sensors experiment [ENDORSED]

I read online that hand dryers and urinals have infrared motion sensors. So we cannot see the light when our hands or bodies hit it because the detecting light is not in the visible region.
by Noah Carey 1G
Wed Apr 18, 2018 6:47 pm
Forum: Properties of Light
Topic: Homework 1.15
Replies: 3
Views: 170

Homework 1.15

How do you get the formula v=R(1/(n1)^2-1/(n2)^2)? I see it in the solutions manual but can't understand where it came from.
by Noah Carey 1G
Sun Apr 15, 2018 3:08 pm
Forum: Properties of Light
Topic: Quantized v. Discrete
Replies: 5
Views: 143

Re: Quantized v. Discrete

Adding on to this! in lecture on 4/11/18 he mentioned "the energy of an electron in the H-atom changes as a function of n" What is n? Is it a discrete variable? Because the output of the function is energy, what does n represent? I think what Dr. Lavelle meant is that the function n descr...
by Noah Carey 1G
Sun Apr 15, 2018 2:57 pm
Forum: Photoelectric Effect
Topic: What is a vacuum?
Replies: 7
Views: 243

What is a vacuum?

The photoelectric experiment must be done "in a vacuum." When an experiment is done in a vacuum what does this mean and what does this look like?
by Noah Carey 1G
Sun Apr 15, 2018 2:13 pm
Forum: Photoelectric Effect
Topic: Video module worked example [ENDORSED]
Replies: 1
Views: 86

Video module worked example [ENDORSED]

The question was, "If 3.61 X 10^(19) J is required to remove an electron with zero kinetic energy from a metal surface, what would be the longest wavelength light that could do this?" The video proceeded and combined the equations E=hv and c=(wavelength)Xv in order to find the wavelength, ...
by Noah Carey 1G
Sat Apr 07, 2018 8:17 pm
Forum: SI Units, Unit Conversions
Topic: why do I not use avogadro's number
Replies: 5
Views: 246

Re: why do I not use avogadro's number

You use Avogadro's number when you are working with moles because 1 mole is equal to approximately 6.022 X 10^(23) atoms/molecules/etc.. The question doesn't ask for anything related to moles. It's interesting because it's actually giving you another method to find how many atoms there are in Beryll...
by Noah Carey 1G
Fri Apr 06, 2018 5:25 pm
Forum: Balancing Chemical Reactions
Topic: H.3
Replies: 3
Views: 155

H.3

In exercise H.3, why is it written SiH4 instead of H4Si? I read that Carbon and Hydrogen come before the other atoms and then the rest follow in alphabetic order (Hill System). Is this an exception or am I just confused?
by Noah Carey 1G
Fri Apr 06, 2018 1:28 pm
Forum: Empirical & Molecular Formulas
Topic: Which mass of Hydrogen should I use?
Replies: 3
Views: 150

Which mass of Hydrogen should I use?

Throughout section E's exercises in the solution manual, the mass of Hydrogen is approximated to be 1.01 g/mol. While in section F of the solution manual, the mass of Hydrogen is approximated to be 1.0079 g/mol. Using 1.01 g/mol changed my answer by a hundredth in a couple problems. Is there a reaso...

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