## Search found 106 matches

Sat Mar 14, 2020 7:42 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: bars
Replies: 3
Views: 27

### Re: bars

I think for the nernst equation you could either use bar or atm, because they are almost the same. Also you can use both pressures and concentrations in the same equation, they don't all have to be the same. I don't know why that's the case but that's what my TA told me. Hope this helps.
Sat Mar 14, 2020 7:31 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: q=qP
Replies: 3
Views: 87

### Re: q=qP

yes, p is for pressure, and the qp is delta H at constant pressure. Hope this helps.
Sat Mar 14, 2020 7:29 pm
Forum: Calculating the pH of Salt Solutions
Topic: Is pH normally taken at equilibrium concentrations?
Replies: 3
Views: 158

### Re: Is pH normally taken at equilibrium concentrations?

I think yes, if it doesn't say anything like "the starting or initial pH was...", you can assume it is at equilibrium.
Sat Mar 14, 2020 7:25 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Conjugate Seesaw
Replies: 5
Views: 107

### Re: Conjugate Seesaw

I thought the conjugate seesaw refers to the idea that the stronger the acid the weaker its conjugate base is and vice versa, I could be wrong though.
Sat Mar 14, 2020 7:23 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Cvm/Cpm
Replies: 3
Views: 88

### Cvm/Cpm

When do we use the 3/2R or 5/2R in place of Cvm/Cpm? And when refering to mono, linear, or non-linear what exactly is that talking about. Thanks in advance.
Sat Mar 14, 2020 7:19 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Thermodynamic properties?
Replies: 2
Views: 79

### Re: Thermodynamic properties?

I think thermodynamic properties may be referring to things like entropy, ethalpy, and gibbs free energy, but I'm not entirely sure.
Sun Mar 08, 2020 10:15 pm
Forum: General Rate Laws
Topic: 7A.9
Replies: 5
Views: 45

### 7A.9

Dinitrogen pentoxide, N2O5, decomposes by a first-order reaction. What is the initial rate of decomposition of N2O5 when 3.45 g of N2O5 is confined in a container of volume 0.750 L and heated to 65 C? For this reaction, k= 5.23x10^23 s^-1 in the rate law (for the rate of decomposition of N2O5). Can ...
Wed Mar 04, 2020 6:55 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6.73
Replies: 2
Views: 55

### 6.73

The “aluminum–air fuel cell” is used as a reserve battery in remote locations. In this cell, aluminum reacts with the oxygen in air in basic solution. (a) Write the oxidation and reduction halfreactions for this cell. (b) Calculate the standard cell potential For part A I figured out the half reacti...
Tue Mar 03, 2020 5:51 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6N.15
Replies: 1
Views: 44

### 6N.15

I'm a little confused on how to determine the two half reactions occurring in the cell. Can someone please explain how to determine them? thanks in advance.
Mon Mar 02, 2020 4:36 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6N.3 a)
Replies: 1
Views: 52

### 6N.3 a)

Predict the potential of each of the following cells:
(a) Pt(s)|H2(g, 1.0 bar)|HCl (aq, 0.075 mol/L)||HCl(aq, 1.0 mol/L) | H2(g, 1.0 bar)|Pt(s).

Can someone please explain why Cl is not included in the cell diagram? Thanks in advance.
Mon Mar 02, 2020 11:27 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: 6M.5 c)
Replies: 3
Views: 34

### 6M.5 c)

Can someone please explain why we would include the H+ in the cell diagram, but not include H20 in the diagram for part c? Thanks in advance.
Sun Mar 01, 2020 8:03 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6N.9
Replies: 1
Views: 41

### 6N.9

Can someone please explain how to find the pH? I am aware I will have to use the Nernst equation, but I don't understand how to progress. Thanks in advance.
Sun Mar 01, 2020 6:07 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6M.1
Replies: 1
Views: 44

### 6M.1

A student was given a standard Cu(s)uCu21(aq) half-cell and another half-cell containing an unknown metal M in 1.00 m M(NO3)2(aq) and formed the cell M(s)uM1(aq)uuCu21(aq)uCu(s). The cell potential was found to be 20.689 V. What is the value of E8(M21/M)? I keep getting an answer of 1.029 V but the ...
Sun Mar 01, 2020 4:02 pm
Forum: Balancing Redox Reactions
Topic: 6L.9 a)
Replies: 1
Views: 40

### 6L.9 a)

(a) Write balanced half-reactions for the redox reaction of an acidified solution of potassium permanganate and iron(II) chloride. (b) Write the balanced equation for the cell reaction and devise a galvanic cell to study the reaction (write its cell diagram). How do we know that we don't need to inc...
Sun Mar 01, 2020 3:51 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.7 b)
Replies: 1
Views: 28

### 6L.7 b)

Can someone please explain how to write the half reactions of part b? thanks in advance.
Sun Mar 01, 2020 1:52 pm
Forum: Balancing Redox Reactions
Topic: 6.K5 b)
Replies: 1
Views: 33

### 6.K5 b)

Balance each of the following skeletal equations by using oxidation and reduction half-reactions. All the reactions take place in basic solution. Identify the oxidizing agent and reducing agent in each reaction.

Can someone please explain how to solve part b? Thanks in advance.
Sun Feb 23, 2020 1:45 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: max potential
Replies: 4
Views: 41

### max potential

Can someone please explain the statement max potential is reached when there is very little current flow? (this is from my notes, so I could have written is down wrong) Thanks in advance.
Sun Feb 23, 2020 1:42 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic cell vs battery system
Replies: 3
Views: 43

### Galvanic cell vs battery system

Is a galvanic cell referring to the same thing as a battery system? thanks in advance.
Sun Feb 23, 2020 1:33 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: work
Replies: 8
Views: 79

### work

Will work always negative, because work should not be done on the system (which in this case is the battery system)? Thanks in advance.
Sun Feb 23, 2020 1:30 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: work
Replies: 1
Views: 37

### work

What would be some examples of work that the battery system does?
Sun Feb 23, 2020 1:18 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Anode & cathode
Replies: 5
Views: 69

### Re: Anode & cathode

I kind think of it as the word cathode has a "t" in it, which looks like a "+" sign so we know it gains electrons (which is what happens in reduction), and then anode is the opposite. Hope this helps.
Sun Feb 23, 2020 1:15 pm
Forum: Balancing Redox Reactions
Topic: 6K.3 b)
Replies: 2
Views: 39

### 6K.3 b)

How do we know we should not make a separate half reaction for the oxygen and/or hydrogen in part b, but also in general? Thanks in advance.
Sun Feb 23, 2020 1:10 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: cathode gaining mass
Replies: 2
Views: 30

### cathode gaining mass

Because the anode is slowly losing mass, does that mean the cathode is slowly gaining mass? Thanks in advance.
Sun Feb 23, 2020 1:06 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Le Chatelier’s Principle
Replies: 11
Views: 125

### Re: Le Chatelier’s Principle

I think it is a similar to applying Le Chatelier's to change in temperature. When the cell potential is positive, it means the forward reaction is favored so when it is increased the forward reaction will occur. When the cell potential is negative, the reverse reaction is favored so when it is incre...
Tue Feb 11, 2020 11:34 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 4.7
Replies: 2
Views: 43

### 4.7

(a) Calculate the work that must be done against the atmosphere for the expansion of the gaseous products in the combustion of 1.00 mol C6H6(l) at 25 8C and 1.00 bar. (b) Using data in Appendix 2A, calculate the standard enthalpy of the reaction. (c) Calculate the change in internal energy, DU8, of ...
Mon Feb 10, 2020 2:28 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 4C.3
Replies: 7
Views: 104

### 4C.3

Calculate the final temperature and the change in enthalpy when 765 J of energy is transferred as heat to 0.820 mol Kr(g) at 298 K and 1.00 atm (a) at constant pressure; (b) at constant volume. Treat the gas as ideal. Can someone please explain how to find the final temperature for both parts? Also ...
Sun Feb 09, 2020 9:41 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 4A.3
Replies: 2
Views: 35

### 4A.3

Air in a bicycle pump is compressed by pushing in the handle. The inner diameter of the pump is 3.0 cm and the pump is depressed 20. cm with a pressure of 2.00 atm. (a) How much work is done in the compression? (b) Is the work positive or negative with respect to the air in the pump? (c) What is the...
Sun Feb 09, 2020 1:05 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Higher the heat capacity
Replies: 4
Views: 32

### Re: Higher the heat capacity

Specific heat capacity is the heat required to increase the temperature of a substance by 1° per 1 gram of that substance. Dividing the heat capacity by grams of substance would give you the specific heat capacity. Hope this helps.
Sun Feb 09, 2020 12:59 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Entropy Change with both volume change and temperature change
Replies: 2
Views: 40

### Re: Entropy Change with both volume change and temperature change

I think you would calculate the entropy of the temperature change and volume change separately and then add the values together (since entropy is a state function) to calculate the total change in entropy. So for the change in volume you would use the deltaS = nRln(V2/V1) and for the change in tempe...
Sat Feb 08, 2020 9:41 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Entropy and Pressure
Replies: 3
Views: 31

### Entropy and Pressure

When pressure increases, does entropy decrease? If so can someone please explain why? Thanks in advance.
Sat Feb 08, 2020 8:26 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Measuring ∆G°
Replies: 2
Views: 33

### Re: Measuring ∆G°

I think it means that it is very difficult to measure ∆G° in the lab, so the best way to determine it's value is through calculations with the gibbs energy equation. Hope this helps
Sat Feb 08, 2020 5:41 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: delta S for compression/expansion and isothermal
Replies: 1
Views: 35

### delta S for compression/expansion and isothermal

If the formula deltaS = nRln(V2/V1) is used for change in volume and isothermal, does that mean the pressure is constant as well?
Sun Feb 02, 2020 4:02 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: using mass in calorimeter
Replies: 3
Views: 37

### using mass in calorimeter

In calorimeter calculations, when is mass not taken into consideration?
Sun Feb 02, 2020 2:47 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: degeneracy
Replies: 3
Views: 35

### degeneracy

Can someone explain how degeneracy and the atom arrangements are relevant to entropy? thanks in advance.
Sun Feb 02, 2020 2:42 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: universe is an isolated system
Replies: 4
Views: 27

### universe is an isolated system

Can someone explain why we can say that the universe is an isolated system, when an isolated system means that no energy is transferred to the surrounding? Thanks in advance.
Sun Feb 02, 2020 2:35 pm
Forum: Calculating Work of Expansion
Topic: work integral
Replies: 6
Views: 59

### work integral

When exactly would we need to use the work integral rather than the simplified version of -p(delta)v? Thanks in advance.
Sun Feb 02, 2020 2:30 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Bomb calorimeter
Replies: 1
Views: 27

### Bomb calorimeter

Can someone please explain how a bomb calorimeter works? Like I understand that it is used for measuring specific heat/specific heat under a constant volume, but how exactly does it work? Thanks in advance.
Sun Jan 26, 2020 2:12 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Polyprotic Acids
Replies: 2
Views: 20

### Re: Polyprotic Acids

There were a couple of homework questions about calculating K of polyprotic acids so I would know how to do so. Hope this helps.
Sun Jan 26, 2020 2:10 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Temperature (K)
Replies: 4
Views: 28

### Re: Temperature (K)

A change in temperature would change K because the rate of the reaction would change if the temperature is increased or decreased. Hope this helps.
Sun Jan 26, 2020 2:05 pm
Forum: Phase Changes & Related Calculations
Topic: Phase Changes endo/exo
Replies: 3
Views: 24

### Re: Phase Changes endo/exo

I believe freezing and condensing are exothermic. Hope this helps.
Sun Jan 26, 2020 1:39 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Method Two
Replies: 2
Views: 28

### Re: Method Two

Method two uses bond enthalpies to calculate the change in heat of the reaction. You would use the enthalpies given from a table for the bonds within different molecule. Breaking bonds have positive enthalpies and forming bonds have negative enthalpies. You would add all the enthalpies of broken and...
Sun Jan 26, 2020 1:02 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic reaction
Replies: 18
Views: 244

### Re: Exothermic reaction

When a reaction is exothermic the heat can be considered to be a product, so if the temp increases then the reaction will shift toward the reactants and if the temp decreases then the reaction will shift toward the products. Hope this helps.
Tue Jan 21, 2020 11:23 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Conjugate seesaw
Replies: 3
Views: 46

### Conjugate seesaw

Does the conjugate seesaw apply to the opposite statement or is it just one way? The weaker an acid/base is, the stronger it's conjugate base/acid is.
Mon Jan 20, 2020 9:34 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6D.7
Replies: 3
Views: 40

### 6D.7

Find the initial concentration of the weak acid or base in each of the following aqueous solutions: (a) a solution of HClO with pH 5 4.60; (b) a solution of hydrazine, NH2NH2, with pH 5 10.20.

Can someone please explain how to find part a? Thanks in advance.
Mon Jan 20, 2020 9:34 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6E.3
Replies: 1
Views: 21

### 6E.3

Calculate the pH of 0.010 M H2SeO4(aq), given that Ka1 is very large and Ka2 = 1.23 x10^-2. Can someone please explain how to do this, thanks in advance.
Mon Jan 20, 2020 9:33 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5% rule clarification
Replies: 2
Views: 31

### 5% rule clarification

When approximating for a small Ka, should we always calculate % ionization to ensure it is lower than 5%? Thanks in advance.
Mon Jan 20, 2020 9:32 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5% rule
Replies: 3
Views: 34

### 5% rule

When calculating the 5% ionization, if one of the reactants has a coefficient, of two for example, should the % ionization be 2x/initial x 100%? Thanks in advance
Mon Jan 20, 2020 9:30 am
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: buffers
Replies: 2
Views: 72

### buffers

Will we have to be able to calculate the ph of buffer solutions on the test?
Sun Jan 12, 2020 3:43 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5.61
Replies: 3
Views: 35

### Re: 5.61

Adding water has no effect because liquids and solids do not influence equilibrium or the K value, only aqueous and gasses do. Hope this helps.
Sat Jan 11, 2020 3:40 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: finding change in concentration in ICE tables
Replies: 3
Views: 32

### Re: finding change in concentration in ICE tables

The change in concentration is represented in terms of x and whether there is a coefficient paired with the x depends on if there are coefficients in the balanced equation. The negative signs depends on which way the reaction is occurring. Hope this helps.
Fri Jan 10, 2020 5:46 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Small "x" approximations for cubic equations
Replies: 3
Views: 37

### Re: Small "x" approximations for cubic equations

I believe it was K< 10^-3. Hope this helps.
Thu Jan 09, 2020 9:27 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Comparing K and Q
Replies: 6
Views: 60

### Re: Comparing K and Q

Knowing whether Q in relation to K would tell you at what point the reaction is at. For example, if Q is less than K you would know that it is at a pre-equilibrium state for the forward reaction because the concentration of reactants is higher than the concentration of products. And in terms of when...
Thu Jan 09, 2020 7:36 pm
Forum: Administrative Questions and Class Announcements
Topic: homework question
Replies: 5
Views: 76

### Re: homework question

It can be any five problems, as long as they relate to whatever we have covered in class so far.
Thu Jan 09, 2020 7:27 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: multiplied reaction
Replies: 3
Views: 42

### multiplied reaction

If a reaction is multiplied, for example 2N2(g) + 6H2(g) <-> 4NH3(g) from N2(g) + 3H2(g) <-> 2NH3(g), why would the K value be raised to the second power? If the coefficients of the balanced equation can be reduced by some factor why would you need to raise K to some power? Thanks in advance.
Sun Dec 08, 2019 3:53 pm
Forum: Properties of Light
Topic: Light acting like a wave
Replies: 4
Views: 155

### Light acting like a wave

What are some instances that show light acts like a wave and not a particle?
Sun Dec 08, 2019 3:49 pm
Forum: Bronsted Acids & Bases
Topic: NH3
Replies: 5
Views: 142

### NH3

If a molecule has NH3 is it safe to assume it is a base?
Sun Dec 08, 2019 3:46 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: chelating ligands [ENDORSED]
Replies: 21
Views: 6238

### Re: chelating ligands[ENDORSED]

ASetlur_3I wrote:Just to clarify, polydentate ligands are chelating right?

yes all polydentates are chelating
Sat Dec 07, 2019 9:15 pm
Forum: Bronsted Acids & Bases
Topic: 6C.19
Replies: 2
Views: 95

### 6C.19

6C.19 Decide which acid in each of the following pairs is the stronger and explain why: (a) HF or HCl; (b) HClO or HClO2; (c) HBrO2 or HClO2; (d) HClO4 or H3PO4; (e) HNO3 or HNO2; (f) H2CO3 or H2GeO3.

Can someone please explain why HCl4 is stronger than H3PO4? thanks in advance
Wed Dec 04, 2019 10:06 pm
Forum: Identifying Acidic & Basic Salts
Topic: 6D.11
Replies: 1
Views: 53

### 6D.11

Decide whether an aqueous solution of each of the following salts has a pH equal to, greater than, or less than 7. If pH . 7 or pH , 7, write a chemical equation to justify your answer. (a) NH4Br; (b) Na2CO3; (c) KF; (d) KBr; (e) AlCl3; (f) Cu(NO3)2 Can someone please explain why d is neutral and wh...
Sat Nov 30, 2019 11:06 am
Forum: Properties & Structures of Inorganic & Organic Bases
Topic: 6C.17
Replies: 1
Views: 55

### 6C.17

Which is the stronger base, the hypobromite ion, BrO2, or morphine, C17H19O3N? Justify your answer.

How would determine which base is stronger? Thanks in advance.
Sat Nov 30, 2019 11:01 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6B.3
Replies: 2
Views: 52

### 6B.3

A careless laboratory technician wants to prepare 200.0 mL of a 0.025 m HCl(aq) solution but uses a volumetric flask of volume 250.0 mL by mistake. (a) What would the pH of the desired solution have been? (b) What will be the actual pH of the solution as prepared? Can someone please explain how to s...
Sat Nov 30, 2019 10:57 am
Forum: Amphoteric Compounds
Topic: 6A.11
Replies: 2
Views: 37

### 6A.11

Write the chemical equations of the two proton transfer equilibria that demonstrate the amphiprotic character of (a) HCO3; (b) HPO42. Identify the conjugate acid–base pairs in each case.

Csn some one please explain how to do part b of this problem? Thanks in advance.
Sat Nov 30, 2019 10:41 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Relative Acidity
Replies: 4
Views: 67

### Relative Acidity

What does mean for an anion to be stable?
Sat Nov 30, 2019 10:20 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Ka constant
Replies: 5
Views: 88

### Ka constant

What does the Ka equilibrium constant represent and what is it used for? Thanks in advance.
Sat Nov 23, 2019 1:55 pm
Forum: Naming
Topic: [Co(NH3)5Cl]Cl H2O
Replies: 4
Views: 62

### [Co(NH3)5Cl]Cl H2O

How do we know that the NH3 part of the coordination complex is supposed to be called ammine?
Sat Nov 23, 2019 1:47 pm
Forum: Biological Examples
Topic: Histidine
Replies: 2
Views: 42

### Histidine

Dr. Lavelle mentioned that the fifth bond on an iron atom to form a myoglobin protein is a histidine, but what exactly is a histidine?
Sat Nov 23, 2019 1:33 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination number
Replies: 1
Views: 35

### Coordination number

Besides representing the number of molecules/atoms bonded to the central metal atom, what is the use of the coordination number(if there is one)? Thanks in advance.
Thu Nov 21, 2019 12:35 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: dipole-dipole vs induced dipole
Replies: 9
Views: 107

### Re: dipole-dipole vs induced dipole

Dipole-dipole bonds depend on the polarity of molecules where as dipole-induced dipole bonds (aka van der waals forces) depend of the polarizability of electron clouds. hope this helps:)
Wed Nov 20, 2019 11:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angle of bent
Replies: 17
Views: 242

### Bond Angle of bent

Is the bond angle of bent 109.5 or 120? thanks in advance
Mon Nov 18, 2019 5:55 pm
Forum: Hybridization
Topic: hybridization
Replies: 4
Views: 45

### hybridization

What is the purpose of hybridized orbitals? Thanks in advance.
Mon Nov 18, 2019 5:53 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Predicting ditortion
Replies: 2
Views: 37

### Predicting ditortion

What does it mean for the vsepr model to be able to predict the distortion qualitatively but not quantitatively?
Mon Nov 18, 2019 5:53 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: resonance structures in molecular structures
Replies: 4
Views: 44

### resonance structures in molecular structures

Just to clarify, since bonds are treated the same in terms of regions of electron density in the vsepr model, it doesn’t matter what resonance structure is used right?
Mon Nov 18, 2019 5:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AXE formula
Replies: 9
Views: 83

### AXE formula

What does the A in the AXE formula for molecular shape mean and can it ever have subscripts? Thanks in advance :)
Mon Nov 18, 2019 5:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone-bonding pair repulsion
Replies: 2
Views: 36

### Lone-bonding pair repulsion

Can someone please explain why the lone-bonding pair repulsion is lower than the lone-lone pair repulsion? Thanks in advance
Sun Nov 10, 2019 9:18 pm
Forum: Sigma & Pi Bonds
Topic: Sigma vs pi bond
Replies: 3
Views: 55

### Sigma vs pi bond

What is the difference between a sigma bond and a pi bond? Also, what does it mean that a pi bond is unhybridized?
Sun Nov 10, 2019 8:51 pm
Forum: Sigma & Pi Bonds
Topic: Occurance of Hybridization
Replies: 1
Views: 38

### Occurance of Hybridization

Can someone please explain how we know when molecules have hybrid orbitals? Thanks in advance
Sun Nov 10, 2019 8:41 pm
Forum: Bond Lengths & Energies
Topic: Interaction Potential Energy
Replies: 1
Views: 31

### Interaction Potential Energy

Can someone please explain why the interaction potential energy is always negative? Thanks in advance
Sun Nov 10, 2019 8:28 pm
Forum: Dipole Moments
Topic: Identifying dipoles
Replies: 3
Views: 46

### Re: Identifying dipoles

I think electronegativity is the major component to determining dipole moments. However, making the lewis structure can help you determine the molecular structure of a molecule which helps determine the polarity of the molecule as a whole. Hope this helps:)
Wed Nov 06, 2019 12:55 pm
Forum: Einstein Equation
Topic: E=hv vs E=pc?
Replies: 7
Views: 254

### E=hv vs E=pc?

What is the difference between E=hv and E=pc? The notes made it seem that thy were both used to calculate energy of the photon, so would that mean the only difference is the circumstance in which you would use them?
Tue Nov 05, 2019 9:17 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Dino Nuggets 13d
Replies: 2
Views: 125

### Dino Nuggets 13d

Can someone please explain why Sc+2 and potassium don't have the same valence shell electron configuration?
Sun Nov 03, 2019 5:18 pm
Forum: Bond Lengths & Energies
Topic: Charge difference/dipole moment for the midterm
Replies: 1
Views: 40

### Charge difference/dipole moment for the midterm

Will we have to know how to calculate the charge difference/dipole moment for the midterm?
Sun Nov 03, 2019 5:11 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: polarizing power vs. polarizability
Replies: 1
Views: 44

### polarizing power vs. polarizability

What is the difference between polarizing power and polarizability? thanks in advance!
Sun Nov 03, 2019 5:09 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: polarizing power
Replies: 3
Views: 39

### polarizing power

In the lecture, Dr. Lavelle said that ions that cause large distortions have high polarizing powers, but what does large distortion mean? thanks in advance!
Sun Nov 03, 2019 5:03 pm
Forum: Dipole Moments
Topic: Dipole moment
Replies: 3
Views: 46

### Dipole moment

Just for clarification, every covalent bond between two different atoms has a dipole moment, but not every covalently bonded molecule is necessarily polar, right?
Sun Nov 03, 2019 4:59 pm
Forum: Coordinate Covalent Bonds
Topic: coordinate covalent bond
Replies: 2
Views: 42

### coordinate covalent bond

Can someone explain how a coordinate covalent bond is different from just a covalent bond? thanks in advance!
Sun Oct 27, 2019 6:08 pm
Forum: Lewis Structures
Topic: 2B.7
Replies: 4
Views: 40

### 2B.7

The following Lewis structure was drawn for a Period 3 element. Identify the element.

To find the element you would have to count the number of electron are present in the lewis structure and match it up to the element in the third period of the periodic table, right? Thanks in advance.
Sun Oct 27, 2019 5:58 pm
Forum: Octet Exceptions
Topic: octet rule exception
Replies: 3
Views: 55

### octet rule exception

Just for clarification, the octet can be exceeded if atoms are in the d-block?
Sun Oct 27, 2019 5:50 pm
Forum: Lewis Structures
Topic: 2A.19
Replies: 3
Views: 48

### 2A.19

Give the ground-state electron configuration and number of unpaired electrons expected for each of the following ions: (a) Sb 3 + ; (b) Sn 4 +; (c) W 2 +; (d) Br 2-; (e) Ni 2-

Can someone please explain how to find the number of unpaired electrons?
Sun Oct 27, 2019 5:33 pm
Forum: Ionic & Covalent Bonds
Topic: 2A.24
Replies: 3
Views: 42

### 2A.24

On the basis of the expected charges on the monatomic ions, give the chemical formula of each of the following compounds: (a) magnesium arsenide; (b) indium(III) sulfide; (c) aluminum hydride; (d) hydrogen telluride; (e) bismuth(III) fluoride. Can someone please explain how to find a and b? Thanks i...
Sun Oct 27, 2019 5:26 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 5
Views: 78

### Formal Charge

When calculating formal charge, is each single bond counted as one or two shared electrons?
Sun Oct 20, 2019 4:47 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Atomic orbitals
Replies: 5
Views: 78

### Atomic orbitals

What exactly does the "probability of electron density" mean in terms of the electron orbitals?
Sun Oct 20, 2019 4:40 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 1E. 9
Replies: 1
Views: 29

### 1E. 9

f the following sets of four quantum numbers {n,l ,m l ,m s}, identify the ones that are forbidden for an electron in an atom and explain why they are invalid: (a) {4, 2, -1, +1/2}; (b) {5, 0, -1, +1/2}; (c) {4, 4, -1, +1/2}.

Can someone please explain why c) works
Sun Oct 20, 2019 4:30 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 1E.5
Replies: 1
Views: 38

### 1E.5

Which of the following statements are true for many-electron atoms? If false, explain why. (a) The effective nuclear charge Z eff e is independent of the number of electrons present in an atom. (b) Electrons in an s-orbital are more effective than those in other orbitals at shielding other electrons...
Sun Oct 20, 2019 4:19 pm
Forum: *Shrodinger Equation
Topic: Hamiltonian
Replies: 6
Views: 82

### Hamiltonian

What is Hamiltonian and what is used for in terms of the Schrodinger equation?
Sun Oct 20, 2019 3:45 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Opposite spin
Replies: 2
Views: 38

### Opposite spin

I understand that electrons in the same orbital have to have opposite spins, but what exactly does it mean for electrons to have opposite spins?
Sun Oct 13, 2019 11:50 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: En=-hR/n^2
Replies: 3
Views: 88

### En=-hR/n^2

For clarification, is this equation only used in terms of hydrogen atoms? If so, is there a more general equation that applies to other atoms?
Sun Oct 13, 2019 11:33 am
Forum: Properties of Electrons
Topic: circular standing wave
Replies: 2
Views: 30

### circular standing wave

I am a bit confused about what the standing part of "circular standing wave" means? Can someone please clarify? Thanks in advance.
Sat Oct 12, 2019 10:23 pm
Forum: Photoelectric Effect
Topic: 1B.7 part b
Replies: 1
Views: 38

### 1B.7 part b

Sodium vapor lamps, used for public lighting, emit yellow light of wavelength 589 nm. How much energy is emitted by (a) an excited sodium atom when it generates a photon; (b) 5.00 mg of sodium atoms emitting light at this wavelength; (c) 1.00 mol of sodium atoms emitting light at this wavelength? Fo...
Sat Oct 12, 2019 6:12 pm
Forum: Properties of Electrons
Topic: Derivation of De Broglie Equation
Replies: 4
Views: 45

### Re: Derivation of De Broglie Equation

I think he was saying that De Broglie's equation can't be applied to light because the equation only applies to particles with really small masses and light has no mass. I could be wrong but that's how I interpreted it.
Sat Oct 12, 2019 1:15 pm
Forum: Photoelectric Effect
Topic: What is high light frequency?
Replies: 3
Views: 38

### What is high light frequency?

In terms of the photoelectric model, it states that electrons will be ejected from the metal surface if the light frequency is high enough. But at what point is light frequency considered high enough to eject an electron?

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