## Search found 120 matches

Sat Mar 14, 2020 11:25 pm
Forum: Van't Hoff Equation
Topic: Celcius vs Kelvin for T1 and T2
Replies: 68
Views: 461

### Celcius vs Kelvin for T1 and T2

Do we need to be aware of any technical changes to the formula if we decide to use Kelvins vs Celcius in the calculations for temperature in both T1 and T2? Or should we just stick with Kelvin to be safe?
Sat Mar 14, 2020 11:23 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat released/ gained
Replies: 22
Views: 233

### Heat released/ gained

When bonds are being broken/ formed in relation to melting points and freezing points, is energy released when a bond is broken? Or is energy gained? Similarly, is energy released/gained when a bond is formed?
Sat Mar 14, 2020 11:19 pm
Forum: Balancing Redox Reactions
Topic: cathode vs anode
Replies: 11
Views: 347

### Re: cathode vs anode

Remember that the cathode will be on the right and the anode will be on the left. Electrons always flow from left to right because it's commonly accepted that the anode will be left and the cathode will be right.
Sat Mar 14, 2020 11:17 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Electrode Mass
Replies: 10
Views: 570

### Re: Electrode Mass

Changing the mass of the electrode, whether it be the cathode or the anode, will not affect the Ecell. It could be doubled, halved, or changed by any factor; the overall change will have no affect on the Ecell.
Sat Mar 14, 2020 11:14 pm
Forum: Balancing Redox Reactions
Topic: changing half reactions
Replies: 6
Views: 167

### Re: changing half reactions

To find which one is the oxidation half and which one is the reduction half, you subtract the two Ecells and whichever one gives you a positive Ecell is the correct order. Then you analyze which numbers are in which position. The one on the left is the cathode and the one on the right is the anode.
Sat Mar 14, 2020 11:09 pm
Forum: Phase Changes & Related Calculations
Topic: expansion
Replies: 5
Views: 182

### Re: expansion

Reversible expansion means that the expansion is gradual, while irreversible expansion means that the expansion is instantaneous.
Sat Mar 14, 2020 11:08 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: specific vs molar
Replies: 4
Views: 456

### Re: specific vs molar

Specific heat capacity will usually use the weight of the molecule that is being used, like grams or kilograms. Molar heat capacity calculates how much the molecule will change by one degree celcius, given the amount of moles.
Sat Mar 14, 2020 11:04 pm
Forum: First Order Reactions
Topic: First order vs zero-order
Replies: 4
Views: 150

### First order vs zero-order

For the graphs of first order and zero order reactions, why are they both exactly the same? The first order reaction has the Ln of A while the zero order is just A. The slopes for both of the graphs are -k, but how can they be the same when the equations are significantly different?
Sat Mar 14, 2020 10:49 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Replies: 3
Views: 80

When adding water to either the cathode or anode half of a solution, why does this decrease the overall Ecell? Would the reverse for this apply to, where taking away solution would increase the overall Ecell?
Sat Mar 14, 2020 10:43 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Lyndon Review: 1D
Replies: 5
Views: 210

### Re: Lyndon Review: 1D

Changing the size, whether it be an increase or decrease, will have no affect on Ecell. If they try to say the mass of the anode being doubled or halved, nothing will happen to the overall reaction.
Sat Mar 14, 2020 10:41 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Finding the concentration of cathodes/ anodes
Replies: 2
Views: 115

### Finding the concentration of cathodes/ anodes

For solving for the concentration of cathodes or anodes, are you able to use the Nernst equation? I know that there is the ln of Q, which is product over reactant, so how would you know if the anode or cathode is the reactant or product in the equation?
Sat Mar 14, 2020 10:39 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Gibbs free energy
Replies: 18
Views: 300

### Gibbs free energy

Can someone explain the difference between gibbs free energy and standard gibbs free energy?
Sat Mar 14, 2020 10:19 pm
Forum: General Rate Laws
Topic: 7A.15a
Replies: 4
Views: 133

### Re: 7A.15a

It is easiest to find two experiments where changes in one of the reactants is equal to an even factor, like 2 or 3. Then you can cross that off from the two combinations of tests required, leaving you with fewer possibilities to choose from for the next tests.
Sat Mar 14, 2020 9:35 pm
Forum: General Rate Laws
Topic: 7C.7
Replies: 5
Views: 128

### 7C.7

Why does the second part of the reaction count towards the overall rate of the reaction? If the second part is fast, then why would it be counted because the first part is the slow part, which decides how fast the reaction occurs. Step 1 NO + Br2 → NOBr2 (slow) Step 2 NOBr2 + NO → NOBr + NOBr (fast)...
Sat Mar 14, 2020 9:29 pm
Forum: Ideal Gases
Topic: T variable in pv=nrt [ENDORSED]
Replies: 38
Views: 357

### T variable in pv=nrt[ENDORSED]

For the temperature in every calculation using the ideal gas formula, will it always be in Kelvin or will there be times where it is in Celcius? I know that the units have to cancel from the gas constant, but I'm not sure if there is any gas constant that requires celcius instead of Kelvin.
Sat Mar 14, 2020 9:06 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW 5.57
Replies: 3
Views: 143

### Re: HW 5.57

What formula are you referring to? I think for this problem you just use the given equilibrium and initial conditions to create an ice table which can be set equal to the equilibrium constant. The solution manual shows no ice table, just using straight moles and using the equation for the equilibri...
Sat Mar 14, 2020 8:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW 5.57
Replies: 3
Views: 143

### HW 5.57

In part b of the problem, it asks to find the concentration of NO, a reactant in the chemical equation. But when finding it, it takes out the volume part of the formula because the amount of moles stays the same from the reactants and the products. How do we know when we are allowed to do this and w...
Sat Mar 14, 2020 8:30 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Qc vs Kc
Replies: 15
Views: 682

### Qc vs Kc

What are the rules for when Qc is greater than Kc and when Qc is less than Kc? And what happens when the two are exactly equal?
Sat Mar 14, 2020 6:20 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Endothermic vs Exothermic
Replies: 2
Views: 139

### Endothermic vs Exothermic

How do you know when a reaction is favored because it is either endo or exothermic?
Wed Mar 11, 2020 3:16 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: E potential
Replies: 8
Views: 180

### Re: E potential

You can determine which one is the cathode and which one is the anode by subtracting one from the other, and whichever order of numbers gives you a positive E cell, then the number on the left was the cathode and the one on the right is the anode.
Sun Mar 08, 2020 11:52 am
Forum: Zero Order Reactions
Topic: Rearranging First Order Integrated Rate Law
Replies: 1
Views: 66

### Rearranging First Order Integrated Rate Law

When solving for t using the first order integrated rate law, does the other part of the equation have a negative sign? I was looking at the example problem for 7B.3, and it seems to solve the equation without having transferred over the negative sign. [img][/img Screen Shot 2020-03-08 at 11.47.39 A...
Sat Mar 07, 2020 5:09 pm
Forum: General Rate Laws
Topic: HW problem 7A.17
Replies: 1
Views: 77

### HW problem 7A.17

For part a of the problem, it asks to find the order of each reactant. For B, I don't know how to calculate what B equals when setting up the equation. I have (3.02/1.25)^b = 50.8/17.4. When these fractions are simplified, the numbers don't have any common factor. Would I have to use log rules to so...
Sat Mar 07, 2020 2:35 pm
Forum: General Rate Laws
Topic: Unique Average Reaction Rate [ENDORSED]
Replies: 4
Views: 107

### Unique Average Reaction Rate[ENDORSED]

Can someone explain how the equation works? The negative inverse times the regular rate of a reactant equals the negative inverse times the regular rate of a product?
Fri Mar 06, 2020 8:09 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Adding Pt(s) to a Cell Diagram
Replies: 14
Views: 271

### Re: Adding Pt(s) to a Cell Diagram

We must add solid platinum so that the electrons have something to bind to. Whenever no solid is present in the equations given, we have to include platinum. In the oxidizing part of the half reaction, I^- changes to I^2 (gas I assume). Does this mean that because there is no solid present, you hav...
Fri Mar 06, 2020 12:04 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Calculating ln Q
Replies: 20
Views: 359

### Re: Calculating ln Q

Q is the concentration of product divided by the concentration of reactant. [product]/[reactant]. Lots of questions will give you the concentrations and you'll be able to solve from there. When you say product/ reactant, do you mean that you take the part on the right of the cell diagram and divide...
Thu Mar 05, 2020 11:44 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Calculating ln Q
Replies: 20
Views: 359

### Calculating ln Q

Can someone explain what Q is and how to use it in the Nernst equation?
Thu Mar 05, 2020 6:19 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6M.1
Replies: 1
Views: 55

### 6M.1

When setting up the equation for the energy of the cell, the problem gives us the cell diagram with the unknown metal on the left side and the Cu^2+ to Cu on the right side. So when setting up to solve for the unknown metal, I set it as the anode because it was on the left side and the Copper as the...
Thu Mar 05, 2020 5:51 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Adding Pt(s) to a Cell Diagram
Replies: 14
Views: 271

### Adding Pt(s) to a Cell Diagram

For 6L.5 part b, it adds Pt(s) to the Cell Diagram, but how do you know when to add it?
Thu Mar 05, 2020 10:38 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.3
Replies: 1
Views: 63

### 6L.3

How do we know when to do the reverse of a reaction. In 6L.3, it reverses the order of the oxidation half reaction. Aren't you able to just write out the reactions based on the order of the cell diagrams? I'm confused why the answer shows a step of having it reversed and then switching it to the cor...
Thu Mar 05, 2020 12:13 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: How to calculate for n
Replies: 7
Views: 178

### How to calculate for n

When calculating for Gibbs free energy, you use the equation Delta G = -n*F*Ecell, but how do you determine the n? It says to use Equation 1a in the textbook, but I don't know what that equation is. Also, do we have to set up an half reactions for solving for this or will we just be able to plug in ...
Wed Mar 04, 2020 4:43 pm
Forum: Balancing Redox Reactions
Topic: 6k.5
Replies: 3
Views: 72

### 6k.5

For part a, how do you know whether O3 --> 02 is the reduction reaction or oxidizing reaction? Both of them have a 0 charge, and since oxygen has a -2 charge, the left side would have a -6 charge while the right side would have a -4 charge? So would it make this the reduction reaction because it is ...
Wed Mar 04, 2020 4:25 pm
Forum: Balancing Redox Reactions
Topic: Oxidizing and Reducing Agents
Replies: 5
Views: 145

### Oxidizing and Reducing Agents

For clarification, if the element is undergoing oxidation, this makes it the reducing agent? And if an element is undergoing reduction, it makes it the oxidizing agent? Or is it the other way around?
Wed Mar 04, 2020 2:29 pm
Forum: Balancing Redox Reactions
Topic: Finding electron difference of half-reactions
Replies: 2
Views: 84

### Re: Finding electron difference of half-reactions

Also why is Cl2 the oxidizing agent and S2O3^2- is the reducing agent?
Wed Mar 04, 2020 2:19 pm
Forum: Balancing Redox Reactions
Topic: Finding electron difference of half-reactions
Replies: 2
Views: 84

### Finding electron difference of half-reactions

How do you find how many electrons are being gained and lost, and how do you compare the redox reactions so that you have an equal amount of electrons in each half reaction in order to cancel the electrons out and find the final balanced equation. For 6k.3 part a, it has the equation Cl2(g) + S2O3^2...
Wed Mar 04, 2020 2:03 pm
Forum: Balancing Redox Reactions
Topic: Oxidation and Reduction of Carbon and Cromium
Replies: 2
Views: 59

### Oxidation and Reduction of Carbon and Cromium

Can someone explain how you would know which half reactions are being oxidized and reduced in 6k.1. Do you have to look at the elements on each side and determine their states to find which one is oxidized and which one is reduced? And how do you know to add H+ for the Carbon but H20 for the Cromium?
Wed Feb 26, 2020 10:50 pm
Forum: Balancing Redox Reactions
Topic: When to add H+ or H20
Replies: 19
Views: 444

### When to add H+ or H20

When splitting up a redox reaction into its two separate half reactions, how do you know when you would add H20 or H+ to fix the amount of hydrogens one each side of an equation?
Wed Feb 12, 2020 12:31 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Acid and [H3O] Midterm Q
Replies: 3
Views: 74

### Re: Acid and [H3O] Midterm Q

Because they say its a weak acid, you know that the HA is never going to fully dissociate into H30+, so HA doesnt equal H30+. You can calculate HA and it does not equal approximately 0. You have the pka and to find ka, you just do 10^-pka, giving you ka. Then you set that equal to the concentration ...
Tue Feb 11, 2020 2:08 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 4E.5
Replies: 4
Views: 55

### 4E.5

Can someone explain how to set up the calculations for solving the enthalpy using bond enthalpy. In part a of 4E.5 it has 3 C2H2 forms into C6H6, but I don't know how to find which bonds are actually used for calculating the net change.
Sun Feb 02, 2020 11:46 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Reversible/ Irreversible Expansion
Replies: 3
Views: 43

### Reversible/ Irreversible Expansion

Can someone explain the main differences between reversible and irreversible expansion.
Sun Feb 02, 2020 11:41 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pKa and pKb
Replies: 3
Views: 89

### pKa and pKb

Can someone explain the basics to pKa and pKb. I thought it was the product of the two equals pKw and that their product is equal to 14. And when calculating it, you just need to do the -log of the ja or kb. Is there anything else I should know fundamentally when applying this to a problem?
Sun Feb 02, 2020 11:38 pm
Forum: Ideal Gases
Topic: Ideal gas constant
Replies: 4
Views: 76

### Ideal gas constant

On the list of constants, it shows R = 8.206 and also 8.314 with the units of K and mol^-1 and atm^-1 and J. But what is the difference between these two constants; why can’t they both be used?
Sun Feb 02, 2020 11:34 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Energy of a system
Replies: 5
Views: 102

### Energy of a system

When determine whether the energy of a system is increasing or decreasing in energy, can someone explain the difference between when energy (heat) gets added/ removed and what sign that would be.
Thu Jan 30, 2020 1:03 pm
Forum: Calculating Work of Expansion
Topic: 4B.5
Replies: 1
Views: 29

### 4B.5

In converting the work to L x atm, the answer says to use the conversion of 760 Torr x atm^-1, but we are given that the atmospheric pressure is 750. Can someone explain why this is the conversion for the work?
Sun Jan 26, 2020 11:00 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Irreversible Expansion
Replies: 4
Views: 84

### Re: Irreversible Expansion

The equation for irreversible expansion is q = (mass)(heat capacity)(change in temperature). This will calculate how much energy is required to change the temperature of a substance.
Sun Jan 26, 2020 10:42 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacity
Replies: 7
Views: 130

### Re: Heat Capacity

Lower heat capacity means that the substance will easily heat and cool. Heat transfer will also easily happen when the value for the heat capacity is low.
Sun Jan 26, 2020 10:22 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 4A.3
Replies: 3
Views: 57

### Re: 4A.3

What is the change ininternal energy of the system?

The change in U would be equal to be w because no other internal change is happening besides the change in volume, so the answer you get for the work would be equal to U.
Sun Jan 26, 2020 10:17 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Dimensional Analysis for Molar Heat Capacity
Replies: 3
Views: 31

### Re: Dimensional Analysis for Molar Heat Capacity

PranaviKolla2B wrote:Can someone please define molar heat capacity?

By definition, the Molar Heat Capacity is the heat capacity divided by the amount (in moles) of the sample. When using it to determine the heat, you would just need to find the value given in table 4A.2.
Sat Jan 25, 2020 6:54 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Dimensional Analysis for Molar Heat Capacity
Replies: 3
Views: 31

### Dimensional Analysis for Molar Heat Capacity

When trying to cancel out the units for finding the heat needed to change an amount of moles of a substance, do you have to convert the temperature from Celcius to Kelvin? The units for the molar heat capacity have K in it, so I assumed the heat would have to be used in Kelvin, but I am not sure. Ca...
Thu Jan 23, 2020 9:30 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Stoichiometric Coefficients
Replies: 2
Views: 81

### Stoichiometric Coefficients

If a chemical equation has a stoichiometric coefficient of 2, then when you put the change for that molecule in the ice table, would you add a two in front of that change? And when writing the equilibrium constant, would you put whatever value of concentration you for it and square it because the va...
Sun Jan 19, 2020 9:17 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5% rule
Replies: 4
Views: 72

### Re: 5% rule

The five percent rule is when you are checking to see if your approximation for the equilibrium constant is valid. You apply it by taking the equilibrium concentration and dividing by the initial concentration and multiplying by 100. If less than five percent, then your approximation is valid. But i...
Sun Jan 19, 2020 9:13 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: question 6B.7
Replies: 4
Views: 70

### Re: question 6B.7

Make sure to remember that significant figures for logs involves the numbers after the decimal. So if there were two significant figures given in the problem, setting up the equation for pH would involve using two significant figures after the decimal point.
Sun Jan 19, 2020 9:08 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5% rule
Replies: 8
Views: 81

### Re: 5% rule

If the value you get is more than 5%, you would know because the value should be significantly higher so that you are sure that it's not a valid approximation. If it's close around the 5% range, then you should redo the problem and make sure not to round any of the numbers until the final answer.
Tue Jan 14, 2020 10:44 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6B.9 Hw problem
Replies: 3
Views: 75

### Re: 6B.9 Hw problem

I also did the math for this problem and the book said my answers were wrong, though I think the book is wrong. When calculating the pH for part a using 1.5 moles of H30, my calculator gives the pH as -.176. The answer shows it being positive .176, which is wrong. If 1 mole of Hydrochloric Acid (HCI...
Tue Jan 14, 2020 9:54 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6A.19
Replies: 1
Views: 53

### 6A.19

For part c of the question, it asks the molar concentrations of OH when given H30. It gives 3.1 mol of H30, so I divided (1.0 x 10^-14) / (3.1) and got 3.2 x 10^-15 mol/L. But the answer says that it is 3.2 x 10^-12 and writes that the denominator is supposed to be 3.1 x 10^-3. Why is that the value...
Sun Jan 12, 2020 11:28 pm
Forum: Ideal Gases
Topic: When is the Ideal Gas Law Not Applicable?
Replies: 2
Views: 37

### Re: When is the Ideal Gas Law Not Applicable?

It can be applied, you would just need to have enough information to solve for the unknown. Is there a specific homework question you are referencing?
Thu Jan 09, 2020 10:13 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: HW 5J.5
Replies: 8
Views: 67

### HW 5J.5

For part b of the homework problem, it has the chemical equation of H2O(g) + C(s) <> H2(g) + CO(g). I thought that there are the same amount of moles for reactants and products, but the answer says that reactants are favored. Can someone explain why they are favored and not equal?
Thu Jan 09, 2020 9:30 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW 5I.15
Replies: 3
Views: 58

### Re: HW 5I.15

The reaction is occurring in the forward direction, which means the solid NH4HS will yield more of the products -- in this case, the products are NH3 and H2S. In other words, the initial amount of NH3 (0.200 mol) will increase by x because of the reaction of NH4HS. So does this mean that whenever w...
Thu Jan 09, 2020 8:50 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW 5I.15
Replies: 3
Views: 58

### HW 5I.15

When writing out the table for the initial, change, and equilibrium concentrations, the problem wants us to calculate the equilibrium concentration for NH3 and H2S. They give us .2mol/L for NH3 and nothing for H2S. So I wrote the initial as .2 for NH3 and 0 for H2S. But for the change, the answer sa...
Tue Jan 07, 2020 11:28 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5H.1
Replies: 1
Views: 27

### 5H.1

For parts b and c, the question asks to determine K from the given chemical equation. Both of them show the exponents to be either halved or doubled, but can someone explain why this would mean that K need to be has to be square rooted or raised to the power of 2. Why couldn't you divide/ multiply K...
Mon Jan 06, 2020 5:41 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Writing Equilibrium Constant Labels
Replies: 4
Views: 75

### Writing Equilibrium Constant Labels

When writing the products and reactants for the equilibrium constant, why do we add P before the formula that is part of the chemical equation? Does this represent the partial pressure?
Sun Dec 08, 2019 3:39 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Pi bond order
Replies: 3
Views: 128

### Re: Pi bond order

Yeah, you just have to change the C to whatever atom it is that is bonded to another atom.
Sun Dec 08, 2019 10:44 am
Forum: Naming
Topic: Naming
Replies: 7
Views: 229

### Re: Naming

Yes you would only use it for the atoms that are inside the brackets in a complex.
Sun Dec 08, 2019 10:40 am
Forum: Conjugate Acids & Bases
Topic: Finding Conjugate A and B
Replies: 6
Views: 177

### Finding Conjugate A and B

When trying to find the conjugates to acids and bases, all you have to do is remove an H or add an H? And this reaction would happen in water.
Sat Dec 07, 2019 4:13 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: CO3 2-
Replies: 1
Views: 37

### Re: CO3 2-

I think that it would normally be monodentate because the bond angle between the two oxygens is 120 degrees, meaning it's too small of an angle for two oxygen atoms to bind to a single metal. But in rare cases, it can be bidentate.
Tue Dec 03, 2019 5:42 pm
Forum: Administrative Questions and Class Announcements
Topic: Early Quantum Review Session
Replies: 3
Views: 71

### Re: Early Quantum Review Session

Final Update: Tony made it, everything is good again. He will be going over review until the next session starts for anyone who left early.
Tue Dec 03, 2019 5:32 pm
Forum: Administrative Questions and Class Announcements
Topic: Early Quantum Review Session
Replies: 3
Views: 71

### Re: Early Quantum Review Session

Update: Most people have left, but there are still a few of us staying strong and waiting for Tony.
Tue Dec 03, 2019 5:15 pm
Forum: Administrative Questions and Class Announcements
Topic: Early Quantum Review Session
Replies: 3
Views: 71

### Early Quantum Review Session

Wondering if Tony is still coming to do the review session, I’m sitting here wondering if I should still wait.
Sun Dec 01, 2019 11:20 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Deprotonated Acids
Replies: 2
Views: 54

### Deprotonated Acids

I know that deprotonated acids are supposed to have transfered their proton from one species to another, and that strong acids will be fully deprotonated. But for weak acids, will we need to know the percent of the ions or molecules that are depronated in a solution. Is there any calculations we wou...
Sun Dec 01, 2019 10:58 pm
Forum: Properties & Structures of Inorganic & Organic Bases
Topic: Recognizing Bases in Chemical Equations
Replies: 2
Views: 118

### Recognizing Bases in Chemical Equations

Is a common trend for bases to have an OH or O in the formula? I know for acids that it says that they will give up a hydrogen and that bases will accept something, but do they normally have oxygen or hydroxide in them?
Sun Dec 01, 2019 10:50 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Molecules combining with water
Replies: 5
Views: 93

### Molecules combining with water

For J.17, it asks for "Write the chemical equation for the proton transfer reaction of this cation or anion with water" and for part B, it gives KClO, which I know is an acid. But how does combining it with water form the cation/ anion, because these reactions are supposed to form salts an...
Sun Dec 01, 2019 9:51 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: J.11
Replies: 2
Views: 86

### J.11

The question gives four pictures and asks "Which of the following images best represents a solution of hydrochloric acid?" The answer is the picture where there are just hydrogen and Cl atoms floating in a space, but not connected to each other. Why does this best represent a solution of h...
Sun Dec 01, 2019 9:24 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Neutralization Reactions
Replies: 2
Views: 396

### Balancing Neutralization Reactions

When balancing equations, you usually only know that the products are going to be some form of salt and H20. But how do you know how much of the reactants to use to make the equation balanced? And when certain molecules have an exponent, like potassium phosphate, do they have to be neutral in order ...
Mon Nov 25, 2019 5:36 pm
Forum: Hybridization
Topic: 2F.17
Replies: 1
Views: 31

### 2F.17

The question asks "Noting that the bond angle of an sp3 hybridized atom is 109.5 and that of an sp2 hybridized atom is 120, do you expect the bond angle between two hybrid orbitals to increase or decrease as the s-character of the hybrids is increased?" Why is the answer to this that if s ...
Mon Nov 25, 2019 5:10 pm
Forum: Hybridization
Topic: Finding Hybrid Orbitals
Replies: 1
Views: 34

### Finding Hybrid Orbitals

When looking at the lewis structure of a molecule, if there are lone pairs on the central atom, do you count that towards the total amount of bonds? Like if an atom had three single bonds and then a lone pair, its hybrid orbitals would be sp^3 because you would be counted as having four atomic orbit...
Sun Nov 24, 2019 11:36 pm
Forum: Hybridization
Topic: Hybridization Formulas
Replies: 2
Views: 54

### Hybridization Formulas

What are the different formulas for making arrangements of electron pairs. There are three formulas that involve the S and P orbital with Px and Py but I don't understand how they apply to hybrid orbitals.
Sun Nov 24, 2019 11:15 pm
Forum: Hybridization
Topic: C2H4
Replies: 2
Views: 54

### Re: C2H4

Because there are only three bonds on the central atom carbon, that means that it has to have the hybridization 2p^3. This also means that the number of hybrid orbitals will be 3. When determining the hybridization, you look at the bonds made on the central atoms, not just the amount of central atom...
Sun Nov 24, 2019 11:05 pm
Forum: Hybridization
Topic: Overlapping of Orbitals
Replies: 2
Views: 97

### Overlapping of Orbitals

Can someone explain how the overlapping of orbitals is significant for sigma bonds and pi bonds. And how this applies to the hybridization of the central atom.
Sun Nov 24, 2019 10:30 pm
Forum: Hybridization
Topic: Hybridization Electron Arrangements
Replies: 2
Views: 91

### Hybridization Electron Arrangements

Why are there only certain VSEPR electron arrangements for determining the hybridization of a central atom? Why isn't angular or See Saw or Square Planar possible VSEPR models that can be used for hybridization.
Tue Nov 19, 2019 8:19 pm
Forum: Lewis Structures
Topic: XeO2F2 Lewis Structure
Replies: 2
Views: 131

### XeO2F2 Lewis Structure

Why does Xenon have two double bonds with oxygen and 2 single bonds with fluorine and a lone pair to make the lowest energy level for its lewis structure. I thought that you are only allowed to assign 8 electrons to each atom, but if you were to add it up, Xe would have 14 electrons. Not sure if thi...
Thu Nov 14, 2019 3:11 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: Polar Vs Nonpolar
Replies: 7
Views: 131

### Re: Polar Vs Nonpolar

Drawing the Lewis Structure really helps because then you can visually see where the signs are coming from, if there are no charges then you would see it from the molecule being drawn and if there are charges they can easily be labeled on the Lewis Structure and understood why they are there.
Thu Nov 14, 2019 2:58 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 to remember strength of different intermolecular forces
Replies: 5
Views: 78

### Re: How to remember strength of different intermolecular forces

All molecules have LDF, but these are relatively weak compared to the rest of the intermolecular forces. But this is an easy one to remember because nearly all will have it. In terms of remembering the others, knowing why each bond is formed can give insight into how strong or weak it is.
Thu Nov 14, 2019 2:15 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: Melting Point 3F.5
Replies: 2
Views: 54

### Re: Melting Point 3F.5

For part d, there is no opportunity for Hydrogen bonding in C[2]H[4], and Hydrogen bonds are stronger so that is why CH[3]OH would have a higher melting point (hydrogen bonds can occur between the H's and O's). For part b, I am unsure though since there are the same amount of H and O molecules allo...
Thu Nov 14, 2019 2:08 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: Hydrogen Bonding
Replies: 2
Views: 36

### Re: Hydrogen Bonding

Thank you for explaining, this definitely clears it up!
Thu Nov 14, 2019 9:40 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: Hydrogen Bonding
Replies: 2
Views: 36

### Hydrogen Bonding

For C2H4, the hydrogen atoms bond to the two carbon atoms, but there are no lone pairs left on the carbon. If there were lone pairs left on the carbon atom, would this then make it potential for hydrogen bonding? I know as it stands that the molecule doesn't have hydrogen bonding, asking for clarifi...
Thu Nov 14, 2019 9:33 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: Melting Point 3F.5
Replies: 2
Views: 54

### Melting Point 3F.5

When finding which molecule has the higher melting point, how do you determine it from the hydrogen bonding. For part b and d of 3F.5, is says that the reason one molecule has a higher melting point is because of the hydrogen bonding that is present in one molecule but not the other, but I don't kno...
Thu Nov 14, 2019 9:05 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: 3F.1 Part a
Replies: 4
Views: 115

### Re: 3F.1 Part a

So does this mean that everything that is a molecule will automatically have LDF?
Wed Nov 13, 2019 11:03 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: 3F.1 Part a
Replies: 4
Views: 115

### 3F.1 Part a

Can someone explain the process of finding the answer to part a of this question? It ask "Identify the types of attractive intermolecular interactions that might arise between molecules of each of the following sub- stances: (a) NH2OH". Should I start by drawing the Lewis Structure, and th...
Sun Nov 10, 2019 10:54 pm
Forum: Dipole Moments
Topic: Interaction between Dipole Moments
Replies: 2
Views: 51

### Interaction between Dipole Moments

The interaction that happens between Dipole Moments is what keeps the negative side attracted to the positive side, but will we need to know how they are attracted together, like the force of the two atoms being attracted and how much energy it would take to separate them?
Sun Nov 10, 2019 10:47 pm
Forum: Hybridization
Topic: Hybridization Models
Replies: 4
Views: 168

### Hybridization Models

Will we need to know how to draw the models for each orbital? Or do we just need to know how they are created and the theory behind them?
Sun Nov 10, 2019 10:43 pm
Forum: Bond Lengths & Energies
Topic: Bond Length Trends
Replies: 4
Views: 156

### Bond Length Trends

For Lewis Structures with different lengths of bonds, will the bond lengths for each always be somewhere in between the length of the longest and shortest bond? I know that single bonds are usually longer than shorter bonds, and triple bonds are even shorter.
Wed Nov 06, 2019 2:34 am
Forum: Lewis Structures
Topic: 12 in Dino nuggets
Replies: 2
Views: 99

### Re: 12 in Dino nuggets

For 12b, you would first calculate the total amount of electrons in ClO^4-, which would be 7e- + 4(6e-) + 1e-, giving you 32e-. Then you would draw the Lewis structure that has these amount of electrons accounted for in the whole structure. For 12c, you would do the same steps as part b. After addin...
Wed Nov 06, 2019 2:06 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Delta E
Replies: 1
Views: 46

### Re: Delta E

When Delta E is negative, it means that the difference in energy states is a negative value because the first value was smaller than the second. This would be from solving from an energy state that is higher to lower, like n = 3 to n =1. When an electron is being excited, then the change would be po...
Sun Nov 03, 2019 6:51 pm
Forum: Lewis Structures
Topic: lone pairs versus double bonds
Replies: 2
Views: 37

### Re: lone pairs versus double bonds

There might be lone pairs instead of adding an extra bond because it helps with the formal charge of the central atom. Because lone pairs count as two and bonds only count as one electron, this could make the difference in an atom being neutral or being negative/ positive. It will always want to hav...
Sun Nov 03, 2019 6:43 pm
Forum: Octet Exceptions
Topic: 2C.5
Replies: 2
Views: 44

### 2C.5

How do you know when a chemical structure will actually be a radical. For part c of 2C.5, the formula is chlorine nitrate, ClONO2 (the central O atom is attached to the Cl atom and to the N atom of the NO2 group). If N is supposed to have 5 electrons and the formal charge on it is +1, does that effe...
Sun Nov 03, 2019 5:49 pm
Forum: Lewis Structures
Topic: 2B.19
Replies: 1
Views: 32

### 2B.19

For part A, it asks "Draw the Lewis structure and determine the formal charge on each atom in (a) NO+. But why are the two triple bonded to each other? I understand that the formal charges would be 0 for the N and +1 for the O.
Mon Oct 28, 2019 3:56 pm
Forum: Ionic & Covalent Bonds
Topic: D block trends
Replies: 1
Views: 46

### D block trends

When saying how many electrons there are for an element in the d block, how do you know when to write the electron configuration without the s block and transfer those electrons to the d block. For Ru^+3, the electron configuration is [Kr] 4d^5, but this uses the two electrons from the 5s^2 and puts...
Mon Oct 28, 2019 3:04 pm
Forum: Ionic & Covalent Bonds
Topic: 2A.1
Replies: 2
Views: 46

### 2A.1

The question asks "Give the number of valence electrons (including d electrons) for each of the following elements: (a) Sb; (b) Si; (c) Mn; (d) B." Why are the answers 5, 4, 7, and 3? For most of them, the only valence electrons were from the p block. For a, I thought it would be 3 valence...
Sun Oct 27, 2019 6:44 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 1E.15
Replies: 2
Views: 70

### 1E.15

When writing the electron configuration for rubidium, it goes all the way up to the 5s row. But when writing 4s^2 and 3d^10, would you write the 3d^10 before or after the 4s^2, because both are filled. I think the filled 3d^10 would have more energy, but it also starts with 3 and being consistent wi...
Sun Oct 27, 2019 5:05 pm
Forum: Quantum Numbers and The H-Atom
Topic: 1D.23
Replies: 1
Views: 52

### 1D.23

When solving for orbitals and you are only given that n = 2, why is the answer? Solving for l would give you 1, which corresponds to the P orbital, giving you three. But the answer shows 4. Why is this?
Fri Oct 25, 2019 7:30 pm
Forum: Quantum Numbers and The H-Atom
Topic: 1D.19
Replies: 3
Views: 149

### 1D.19

The problems asks for the number of orbitals given a subshell. Would the answer be finding Ml from L or finding n from L?