## Search found 31 matches

Wed Dec 05, 2018 7:19 pm
Forum: Properties & Structures of Inorganic & Organic Bases
Topic: Memorize strong and weak acids and bases?
Replies: 3
Views: 386

### Re: Memorize strong and weak acids and bases?

I asked a TA and they said that it would be helpful and we should memorize them
Wed Dec 05, 2018 7:14 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 7th Edition 6D11
Replies: 1
Views: 130

### 7th Edition 6D11

Why does KBr have a pH that equals 7?
Wed Dec 05, 2018 7:09 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 7th Edition Problem 6B.9 Solution
Replies: 1
Views: 144

### Re: 7th Edition Problem 6B.9 Solution

You should take the negative log of the H3O+ concentration so the answer is actually -(-.176) which is simplified to +.176
Thu Nov 29, 2018 1:36 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Number
Replies: 10
Views: 387

### Re: Coordination Number

I am not sure how to find the coordination number, however the coordination number is defined as the number of atoms or ions immediately surrounding a central atom in a complex.
Thu Nov 29, 2018 1:35 pm
Forum: Naming
Topic: Common Ligand Names
Replies: 4
Views: 268

### Re: Common Ligand Names

I had the same question too. I am a bit confused because we hadn't gone over the chart in class so I'm not sure to what extent we should memorize the chart
Thu Nov 29, 2018 1:33 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelate
Replies: 6
Views: 327

### Re: Chelate

According to the book definition, a chelate is a complex containing one or more ligands that form a ring of atoms that includes the central metal atom.
Tue Nov 20, 2018 2:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Determining Location of Lone Pair
Replies: 1
Views: 132

### Determining Location of Lone Pair

When determining the location of a lone pair on the central atom, does it matter between which elements the lone pair is placed in? For example in the 7th edition number 2E.23c we have IO2F2- We have iodine as the central atom and have Fluorine on the south and west end of Iodine and Oxygen to be on...
Tue Nov 20, 2018 2:24 pm
Forum: Hybridization
Topic: 7th Edition 2F.15
Replies: 1
Views: 121

### 7th Edition 2F.15

For the 7th Edition number 2F.15, what does it mean when it talks about the s character of hybrids? What is the s character of a hybrid and how can it increase?
Tue Nov 20, 2018 2:20 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: lone pairs
Replies: 4
Views: 251

### Re: lone pairs

Lone pairs on non central atoms should not affect the shape of the molecule
Wed Nov 14, 2018 11:20 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: 6.1 Sixth Edition Intermolecular Forces
Replies: 2
Views: 1799

### Re: 6.1 Sixth Edition Intermolecular Forces

I think CBr4 only has London forces because it is a non polar molecule. London forces are always present so CBr4 only has London forces.
Wed Nov 14, 2018 11:16 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 4
Views: 187

### Re: Bond Angles

We should be able to identify bond angles whether it be for example 180,120, 90 or <120,<90
However we do not need to know the specific bond angle for a specific molecule if it is less than like <120 because the bond angle would vary slightly for each molecule.
Wed Nov 14, 2018 11:13 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Multiple bonds
Replies: 2
Views: 148

### Re: Multiple bonds

Yes, a single/double/triple bond is considered just 1 region of electron density. A lone pair is considered 1 region of electron density as well
Thu Nov 08, 2018 2:08 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Electronegativity
Replies: 6
Views: 315

### Re: Electronegativity

I think oxygen is more electronegative than chlorine because it is on the same period as fluorine. Even though the electronegativity decreases going both down a group and to the left of a period, there is a greater change in electronegativity between periods than groups. (If two elements are placed ...
Thu Nov 08, 2018 2:04 pm
Forum: Resonance Structures
Topic: Finding all Resonance Structures
Replies: 4
Views: 211

### Re: Finding all Resonance Structures

I don't think there are certain "tricks" in drawing resonance structures. The best way would be to look at the formal charges and making sure they are as close to zero (or add up to the ion charge) If the structure consists of different types of bonds and you notice that the different type...
Thu Nov 08, 2018 2:02 pm
Forum: Electronegativity
Topic: What are the trends useful for?
Replies: 12
Views: 470

### Re: What are the trends useful for?

Trends are generally helpful as they give us useful information when drawing Lewis Structures. For example, the electronegativity trend can give us a good idea as to what element to put in the center because we want the least electronegative element in the center.
Wed Oct 31, 2018 5:49 pm
Forum: Trends in The Periodic Table
Replies: 2
Views: 210

If we are comparing the radius of an atom on the very right side of the periodic table (group 17, period 3) with an atom on the left side of the periodic table (group 2, period 4) how should we compare the size of the atomic radius if they are in different groups and their periods are next to each o...
Wed Oct 31, 2018 5:23 pm
Forum: Resonance Structures
Topic: 7th Edition 2C5.C
Replies: 2
Views: 234

### 7th Edition 2C5.C

For 7th edition, chapter 2C number 5C, why is the Lewis structure not a resonance structure if the two oxygens that are attached to the nitrogen are 1 single bond and 1 double bond?
Wed Oct 31, 2018 5:14 pm
Forum: Octet Exceptions
Topic: 7th Edition 2C5.A
Replies: 2
Views: 135

### 7th Edition 2C5.A

On the 7th edition for chapter 2c number 5A, why is the unpaired electron on chlorine as opposed to having it on oxygen?
Mon Oct 29, 2018 1:18 pm
Forum: Lewis Structures
Topic: 7th Edition 2.B.9
Replies: 5
Views: 155

### 7th Edition 2.B.9

Could someone explain why in 2.B.9 in the 7th edition, the Lewis structure for potassium phosphide has the P in the center with 8 electrons, and the K does not have any electrons and isn't attached to the P, but instead just floats around the P?
Wed Oct 24, 2018 5:13 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 1D.23, part c (7th Edition)
Replies: 2
Views: 152

### Re: 1D.23, part c (7th Edition)

n=2 can either be the 2s or 2p subshell. The 2s subshell has 1 orbital while the 2p subshell has 3 orbitals. Since it asks for the general principal quantum number of n=2, we must take into account 2s and 2p so we add 1 orbital + 3 orbitals to get 4 possible orbitals.
Wed Oct 24, 2018 5:10 pm
Forum: Photoelectric Effect
Topic: Question 1.B.15 7th
Replies: 2
Views: 211

### Re: Question 1.B.15 7th

Use the DeBroglie wavelength equation and plug into the numerator Planck's constant. In the denominator you can multiply the mass of an electron (9.11x10^-31 kg) by the velocity which is 3.6x10^6 ms-1. This should give you the desired answer of 2.02 x 10^-10 meters.
Wed Oct 24, 2018 5:06 pm
Forum: Trends in The Periodic Table
Topic: Helium
Replies: 2
Views: 127

### Re: Helium

Helium is part of the s block, not the p block. The electron configuration is 1s2, so even though it does appear on top of the p block when looking at the periodic table, it still belongs to the s block.
Tue Oct 16, 2018 12:18 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: G Orbital
Replies: 2
Views: 483

### G Orbital

When coming across the homework, I noticed one of the problems mentioned something about the g orbital. Does anyone know what the g orbital is and if it is ever used in writing ground state electron configuration?
Tue Oct 16, 2018 12:15 pm
Forum: Quantum Numbers and The H-Atom
Topic: 7th Edition HW 1D.21
Replies: 3
Views: 200

### Re: 7th Edition HW 1D.21

When we are given 5d, 1s, 6f, 2p, I usually like to first identify where that shell/subshell is on the periodic table. Typically when you are looking at the s shell, it has 1 orbital, the p shell has 3 orbitals, the d shell has 5 orbitals, and the f shell has 7 orbitals.
Tue Oct 16, 2018 12:08 pm
Forum: Properties of Light
Topic: Mass of Light
Replies: 5
Views: 310

### Re: Mass of Light

I don't think you can calculate the mass of light. We are given the speed of light which is the constant c=2.99792x10^8 ms^-1, but the mass of light is I believe negligible as someone has already said.
Tue Oct 09, 2018 8:20 pm
Forum: Properties of Light
Topic: Summary Notes Clarification
Replies: 3
Views: 209

### Summary Notes Clarification

In our summary notes, I am reviewing how "in the photoelectric experiment, light sources with long wavelength light cannot eject electrons." Can someone please clarify why this is the case?
Tue Oct 09, 2018 8:15 pm
Forum: Properties of Electrons
Topic: Energy per photon equation
Replies: 3
Views: 202

### Re: Energy per photon equation

yes, because in the equation E=hv, h is a constant. So as the frequency increases, the energy too should increase as well
Tue Oct 09, 2018 8:13 pm
Forum: Properties of Light
Topic: Do I need to memorize the Light Spectrum? [ENDORSED]
Replies: 13
Views: 449

### Re: Do I need to memorize the Light Spectrum?[ENDORSED]

^ I agree. I think we should have a general idea and be familiar with the spectrum, however knowing the exact numbers may not be necessary. But it can never hurt to memorize it!
Tue Oct 02, 2018 6:07 pm
Forum: Significant Figures
Topic: F.15
Replies: 4
Views: 159

### F.15

For question F.15 from the problem sets, I noticed that when calculating the number of mols of H, the setup is 4.60gH/1.008g mol-1 According to the sig fig rules 4.60 has 3 sig figs and 1.008 has 4 sig figs, and when dividing we should take the lowest number of sig figs, however the answer is 4.563 ...
Tue Oct 02, 2018 6:00 pm
Forum: Empirical & Molecular Formulas
Topic: Formula Mass and Molar Mass
Replies: 2
Views: 1293

### Formula Mass and Molar Mass

For question F.17 on the problem sets, what is the difference between formula mass and molar mass?
Tue Oct 02, 2018 5:59 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical Formula Calculations
Replies: 2
Views: 188

### Re: Empirical Formula Calculations

When dividing by the smallest value in solving for the empirical formula, you should usually get a whole number or a number very close to a whole number. In the instances where you get ".99 or .97", I would say rounding up to get the ratios would be appropriate. However if you calculate a ...