## Search found 50 matches

Fri Mar 15, 2019 8:49 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: exercise 14.13 (d)
Replies: 2
Views: 97

### Re: exercise 14.13 (d)

Sorry, I didn't get your point. What should I do with the redox reaction on 2B?
Fri Mar 15, 2019 8:18 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: exercise 14.13 (d)
Replies: 2
Views: 97

### exercise 14.13 (d)

for this question, why is Au(s) used as the electrode for both sides? Isn't Au(s) a product of the redox reaction?
Fri Mar 15, 2019 8:11 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: rules of drawing the cell diagram
Replies: 2
Views: 115

### Re: rules of drawing the cell diagram

What about the cathode side? the reactant is always on the left side of the products, or are reactants closer to the electrode than the product?
Fri Mar 15, 2019 7:54 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: rules of drawing the cell diagram
Replies: 2
Views: 115

### rules of drawing the cell diagram

Is there a specific order when there are multiple molecules present besides the electrode?
for example
Pt(s)|H2(g), H+(aq)||Fe3+(aq), Fe2+(aq)|Pt(s)
for the H2 gas and H+ on the right side of Pt for the anode, is there a specific order?
Thu Mar 14, 2019 2:01 pm
Forum: Second Order Reactions
Topic: second order half life calculation
Replies: 1
Views: 102

### second order half life calculation

For exercise 15.35 on the 6th edition book, can I use the half-life and multiply by 4 to find the time for the reactant to become 1/16 of the original amount in a second-order reaction?
Thu Mar 14, 2019 1:58 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: exercise 15.65
Replies: 1
Views: 75

### exercise 15.65

In this question, the equilibrium of the reaction is K=[B][C]/[A]^2 Should we consider the reaction order when calculating the equilibrium constant using rate constant? Doesn't [A]^2 means the order of reaction for A is two? Why can we directly plug in the rate constants provided regardless of the r...
Wed Mar 13, 2019 10:54 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: exercise 15.17
Replies: 1
Views: 257

### exercise 15.17

for c) in this question, why can we use the initial rate for the product G to calculate the rate constant?
quantitatively, what does the general rate law equals to?
What are the differences between initial rate, general rate law, instantaneous rate, and unique rate of reaction?
Wed Mar 13, 2019 10:30 pm
Forum: General Rate Laws
Topic: reaction order and reaction quotient
Replies: 1
Views: 75

### reaction order and reaction quotient

what is the relationship between reaction quotient and reaction order? when writing the rate law for a reaction, the power of the reactants is determined by the reaction order of the reactant instead of the reactant's reaction quotient?
Wed Mar 13, 2019 10:04 pm
Forum: General Rate Laws
Topic: determining the rate of reaction for individual components in the reaction
Replies: 1
Views: 71

### determining the rate of reaction for individual components in the reaction

When asking about the reaction rate of a reactant, should the value be positive or negative?
I know that for products, more are forming, so the reaction rate for the individual product is positive.
Tue Mar 12, 2019 10:26 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: exercise 11.77 6th edition
Replies: 2
Views: 127

### exercise 11.77 6th edition

In b) why is the reaction endothermic? Is it because a halogen is stable in the form X2, so 2X is an unstable form thus has higher energy?
Tue Mar 12, 2019 9:40 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: exercise 11.41
Replies: 1
Views: 80

### exercise 11.41

In this question, how can I calculate Kc with gas? How can I know the concentration of gases?
Tue Mar 12, 2019 8:52 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: value of equilibrium constant
Replies: 1
Views: 65

### value of equilibrium constant

What are the factors that can influence the value of the equilibrium constant? Why is d) in the question true?
Tue Mar 12, 2019 6:59 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Heat of combustion
Replies: 1
Views: 84

### Heat of combustion

How can I use the heat of combustion to calculate the reaction enthalpy?
Mon Mar 11, 2019 7:05 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: reducing power and oxidizing power
Replies: 2
Views: 189

### reducing power and oxidizing power

How do I know the strength of reducing power and oxidizing power using standard reduction potential?
Sun Mar 10, 2019 12:46 pm
Forum: General Rate Laws
Topic: how to determine the rate law
Replies: 2
Views: 57

### how to determine the rate law

What effect does temperature have on reaction constant k? in many homework problems, I see there are specific values of k relating with different temperature.
Mon Feb 25, 2019 9:11 pm
Forum: Balancing Redox Reactions
Topic: balancing redox reaction
Replies: 2
Views: 145

### balancing redox reaction

How can I find the skeletal reaction for the redox reaction? After finding one of the skeletal reaction, do I just take whatever is left from the overall reaction for the other skeletal reaction?
Mon Feb 25, 2019 9:09 pm
Forum: Balancing Redox Reactions
Replies: 5
Views: 260

Is it true that the redox reaction always involves oxygen? From the homework problems, there is always oxygen present.
Sat Feb 23, 2019 7:10 pm
Forum: Balancing Redox Reactions
Topic: problem 14.5 6th edition
Replies: 1
Views: 74

### problem 14.5 6th edition

can someone help me out with this question? how can I find the skeletal reaction when the product is both produced by the oxidizing agent and the reducing agent?
Tue Feb 12, 2019 9:47 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: practice midterm question
Replies: 3
Views: 142

### practice midterm question

Can somebody explain how to calculate reaction enthalpy using enthalpy of combustion? Why is the enthalpy of the reaction negative?
Sun Feb 10, 2019 7:23 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: calculation of change in entropy
Replies: 3
Views: 148

### calculation of change in entropy

when volume and temperature change at the same time, how can I calculate the overall change of entropy
Wed Feb 06, 2019 11:21 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Calculate degeneracy
Replies: 1
Views: 94

### Calculate degeneracy

How can I calculate degeneracy (w), how is the volume related to degeneracy?
Thu Jan 31, 2019 11:51 pm
Forum: General Science Questions
Topic: Redox reaction
Replies: 1
Views: 431

### Redox reaction

I couldn't find links to discussion about Redox reactions, so here I am, posting a redox reaction question under the general science board.
Can someone help me out with the question shown in the picture, what is the relationship between losing and gaining electrons with losing and gain H+ (H atom)?
Mon Jan 21, 2019 11:38 am
Forum: Bronsted Acids & Bases
Topic: protonation and deprotonation
Replies: 2
Views: 321

### protonation and deprotonation

what are protonation and deprotonation? How should I calculate the percentage of protonation and percentage of deprotonation?
Fri Jan 18, 2019 8:25 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Ka Kb significance
Replies: 3
Views: 1041

### Ka Kb significance

What are the significance of Ka Kb and pKa pKb, why do we calculate them? What is the relationship between pH pOH and pKa pKb?
Mon Jan 14, 2019 7:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: the value of equilibrium constant
Replies: 3
Views: 139

### the value of equilibrium constant

Is the value of the reaction quotient the same for gas when calculating it by gas concentration and when calculating it by partial pressure?
Mon Jan 14, 2019 6:59 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: effect on equilibrium by changing volume
Replies: 2
Views: 126

### effect on equilibrium by changing volume

How do I explain the change in equilibrium with reaction quotient (Q) after changing the volume?
Thu Jan 10, 2019 8:45 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: calculation of equilibrium constant
Replies: 2
Views: 101

### calculation of equilibrium constant

1. If the reaction includes both aqueous solutions and gases, how can we calculate the equilibrium constant?
2. Under what condition can the concentration(partial pressure) of water be included in the calculation of equilibrium constant?
Sat Dec 08, 2018 9:08 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: how can a hydrogen bond form
Replies: 2
Views: 272

### Re: how can a hydrogen bond form

however, on the practice midterm, question (d) on the attachment, how is the answer 4 then?
Sat Dec 08, 2018 2:05 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: how can a hydrogen bond form
Replies: 2
Views: 272

### how can a hydrogen bond form

Is it necessary for electronegative atoms like Oxygen, Nitrogen, Florine to bond to hydron for them to form hydrogen bonds with other molecules that have N,O,F bonded to hydrogen?
Sat Dec 08, 2018 11:56 am
Forum: Naming
Topic: order of ligand name
Replies: 5
Views: 419

### order of ligand name

When there are a neutral and a charged ligand in the coordination complex, should the neutral ligand be in front of the charged ligand regardless of the alphabetical order? relating to question 31(d) on the 6th edition book (page762)
Wed Dec 05, 2018 2:00 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: unit
Replies: 3
Views: 115

### unit

What should be the unit of the concentration when calculating the pH of the solution?
Sun Dec 02, 2018 8:03 pm
Forum: Hybridization
Topic: Hybridization of CH3CN
Replies: 2
Views: 157

### Hybridization of CH3CN

For Question8 in 2011 midterm. What is the hybridization of the Nitrogen atom in CH3CN? What about the lone pair on N? Are there different hybridizations for the 3 bonds between the central Carbon atom and the Nitrogen atom? How should I represent the hybridizations in the final if there are questio...
Sun Dec 02, 2018 2:59 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: structure of molecule for coordination number of 4
Replies: 1
Views: 73

### structure of molecule for coordination number of 4

The syllabus says that we need to identify and draw structures of coordinate compounds. How do I know whether the shape of the molecule is tetrahedron or square-planar when the coordination number is 4.
Sun Dec 02, 2018 1:12 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: why do we care about coordination
Replies: 2
Views: 78

### why do we care about coordination

we have talked a lot about coordination, but why do we care? what is the significance of coordinates?
Sun Nov 25, 2018 8:08 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: text book question 6th edition
Replies: 1
Views: 109

### text book question 6th edition

For question 6.5.c in the 6th edition, why does CHI3 has greater melting point than CHF3. I thought that Fluorine has greater electronegative thus causing the greater dipole moment.
Thu Nov 22, 2018 11:08 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Ethylene bond angle
Replies: 2
Views: 147

### Re: Ethylene bond angle

so the presence of a double bond and a bond with another carbon doesn't affect the other bond angles?
Wed Nov 21, 2018 11:04 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Ethylene bond angle
Replies: 2
Views: 147

### Ethylene bond angle

I'm not sure how the bond angles in Ethylene is affected by different atoms. how are the bond angles of H-C-H different from that of H-C-C? and why?
Thu Nov 15, 2018 1:57 am
Forum: Determining Molecular Shape (VSEPR)
Topic: bond angle
Replies: 4
Views: 208

### bond angle

will double and triple bonds in a muti-bond structure affect the bond angle?
Thu Nov 08, 2018 10:42 am
Forum: Lewis Structures
Topic: Formal charges
Replies: 15
Views: 493

### Formal charges

I was informed that formal charges are a component of the Lewis structure, do I have to write the formal charges for each of the atoms in the molecule when writing a Lewis structure.
Fri Nov 02, 2018 10:32 pm
Forum: Quantum Numbers and The H-Atom
Topic: degeneracy of the a 4p orbital
Replies: 9
Views: 960

### degeneracy of the a 4p orbital

for question 5.c on test2:
how exactly should I answer: what is the degeneracy of a 4p orbital?
Fri Nov 02, 2018 10:25 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: question 4.b on Test2
Replies: 1
Views: 108

### question 4.b on Test2

what is the correct answer for question 4.b on test2:
describe the nature of the energy levels in the Ne atoms
Tue Oct 30, 2018 1:33 pm
Forum: Quantum Numbers and The H-Atom
Topic: degeneracy
Replies: 2
Views: 183

### degeneracy

How can I interpret the meaning of degenerate? How should I answer the question on test2 that asks about the degeneracy of a 4p orbital?
Mon Oct 22, 2018 9:32 pm
Forum: Properties of Light
Topic: worksheet3 question11
Replies: 3
Views: 200

### worksheet3 question11

Why is a true and d false?
Mon Oct 22, 2018 8:31 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: How do I identify excited state through the electronic configuration
Replies: 5
Views: 1439

### How do I identify excited state through the electronic configuration

Does the down spin represent a higher energy? Is it okay if I put down arrows instead of arrows pointing up? How do I tell if the atom is in an excited state by looking at the electron configuration?
Sun Oct 21, 2018 3:41 pm
Forum: Properties of Light
Topic: measuring wavelength
Replies: 5
Views: 244

### measuring wavelength

How can I tell if a wavelength is detectable? Is there a limit for current technologies?
Tue Oct 16, 2018 4:39 pm
Forum: Properties of Light
Topic: property of light
Replies: 2
Views: 67

### property of light

I'm confused, if the number of photons only influence the intensity of the light instead of the energy of the light, then why can the book ask questions like the photo attachment?
Sat Oct 13, 2018 11:24 pm
Forum: Properties of Light
Topic: energy of light
Replies: 2
Views: 55

### Re: energy of light

If the number of particles determines the amount of energy given off, then the assumptions in the photoelectric effect example would be wrong, since we can manipulate the number of photons to excite electrons no matter what the frequency is. How is this possible?
Sat Oct 13, 2018 8:31 pm
Forum: Properties of Light
Topic: energy of light
Replies: 2
Views: 55

### energy of light

When excited electrons fall back from the excited state to ground state, what determines the energy besides frequency and wavelength? Will the number of electrons falling back affects the amount of energy given off?

To see a specific question: go to exercise 1.25 in the 6th edition book.
Mon Oct 08, 2018 6:42 pm
Forum: Significant Figures
Topic: significant figures
Replies: 5
Views: 501

### significant figures

what if I want to round 14.996 to the nearest hundredth? what result will I get?
Tue Oct 02, 2018 11:11 pm
Forum: Photoelectric Effect
Topic: equation generated through the photoelectric experiment
Replies: 1
Views: 90

### equation generated through the photoelectric experiment

One of the questions in the video module about photoelectric effect asks about the new equation that was given rise by the photoelectric experiment, which equation should I put?