Search found 61 matches

by Maggie Doan 1I
Fri Mar 15, 2019 3:13 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Test 2
Replies: 5
Views: 109

Re: Test 2

So can we assume we always assume that when the pH is 7 then it will be pH + pH = 14 in which we will divide by 2.
by Maggie Doan 1I
Fri Mar 15, 2019 10:09 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Test 2
Replies: 3
Views: 85

Re: Test 2

When would ΔG=0?
by Maggie Doan 1I
Wed Mar 13, 2019 2:15 pm
Forum: First Order Reactions
Topic: 7B.9
Replies: 2
Views: 55

7B.9

For the first order reaction A \rightarrow 3B + C, When [A]0 = .015 mol/l, the concentration of B increases to .018 mol/ L in 3.0 min. a) What is the rate of constant for the reaction expressed as the rate of loss of A? I got the answer 1.7 minutes but the answer is .17 minutes. I was wondering how ...
by Maggie Doan 1I
Tue Mar 12, 2019 11:37 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Test 2
Replies: 3
Views: 85

Test 2

7b. The combustion of a gas used to heat a BBQ at a pool party.

Would this be a spontaneous reaction?
by Maggie Doan 1I
Tue Mar 12, 2019 11:28 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Test 2
Replies: 5
Views: 109

Test 2

5. The ionic dissociation of water is given by the following reaction: The ΔH for the reaction is 58kJ/mol. The Kw for the reaction at 25°C is 10^-14. Is a pH of 7 acidic or basic at 30°C? 2H2O(l) \leftrightarrow H30+(aq) + OH-(aq) What is the pH? I used the nerst equation but I'm not getting the ri...
by Maggie Doan 1I
Tue Mar 12, 2019 11:23 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Test 2 Cell Diagram
Replies: 3
Views: 91

Test 2 Cell Diagram

When do we use a comma for the cell diagram?
Do we also use a conductor when there is no solid present?
by Maggie Doan 1I
Thu Mar 07, 2019 12:34 am
Forum: General Rate Laws
Topic: 7A.15
Replies: 1
Views: 42

7A.15

How do you find the order for the reactants and overall order?

I'm confused on when to use each experiment?
by Maggie Doan 1I
Thu Mar 07, 2019 12:09 am
Forum: General Rate Laws
Topic: 7A.13
Replies: 3
Views: 68

7A.13

In the reaction CH3Br + OH- CH3OH + Br-, when the OH- concentration alone was doubled, the rate doubled; when the CH3Br concentration alone was increased by a factor of 1.2, the rate increased by a factor of 1.2. Write the rate law for the reaction.

How do you determine the rate law?
by Maggie Doan 1I
Thu Feb 28, 2019 12:19 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.5
Replies: 1
Views: 49

6L.5

Write the half reactions, balanced equation for the cell reaction and the cell diagram.
d) Au^+(aq) Au(s) + Au^3+(aq)

Why do we use the solid Au for the anode?
by Maggie Doan 1I
Wed Feb 27, 2019 11:33 pm
Forum: Balancing Redox Reactions
Topic: 6K.5
Replies: 2
Views: 64

Re: 6K.5

Thank you I forgot about the negative charge on OH so I put the electrons on the wrong side.
by Maggie Doan 1I
Wed Feb 27, 2019 10:29 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.1
Replies: 1
Views: 43

6L.1

When calculating the standard reaction GIbbs free energy how do we find n?
by Maggie Doan 1I
Wed Feb 27, 2019 8:29 pm
Forum: Balancing Redox Reactions
Topic: 6K.5
Replies: 2
Views: 64

6K.5

Balance each of the following skeletal equations by using oxidation and reduction half reactions.

a) O3 + Br- O2 + BrO3-

How do you balance the half reaction of O3 O2?
by Maggie Doan 1I
Wed Feb 27, 2019 6:43 pm
Forum: Balancing Redox Reactions
Topic: 6K.3
Replies: 1
Views: 47

6K.3

Balance each of the following skeletal equations by using oxidation and reduction half reactions.

d) Cl2 HClO + Cl2
by Maggie Doan 1I
Tue Feb 26, 2019 10:33 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Midterm
Replies: 5
Views: 107

Midterm

What does it mean for part 1c to comment on the relative stability of the reactants and products?
by Maggie Doan 1I
Mon Feb 11, 2019 12:38 am
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: 4G. 2B 7th edition
Replies: 2
Views: 57

4G. 2B 7th edition

Suggest a reason why the entropy of ice is nonzero at T= 0; think about how the structure of ice is affected by the hydrogen bonds.
by Maggie Doan 1I
Mon Feb 11, 2019 12:13 am
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: 4G. 1B 7th edition
Replies: 1
Views: 48

4G. 1B 7th edition

Calculate the entropy of a sample of a solid in which it is supposed that a substituted benzene molecule, C6H5F, may be found in any one of six orientations with the same energy at T=0. Suppose there is 1.0 mol of molecules in the sample.

Why is one mole of the molecule multiplied with the equation?
by Maggie Doan 1I
Mon Feb 11, 2019 12:02 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond enthalpies
Replies: 10
Views: 164

Bond enthalpies

To solve for bond enthalpies, do we have to know the lewis structure of the molecules?
by Maggie Doan 1I
Wed Feb 06, 2019 11:35 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: 7th edition 4F.9
Replies: 1
Views: 44

7th edition 4F.9

Calculate the change in entropy when the pressure of 1.5mol Ne(g) is decreased isothermally from 15.0 atm to .500 atm. Assume ideal behavior.
by Maggie Doan 1I
Wed Jan 30, 2019 8:18 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 4B.3
Replies: 1
Views: 53

4B.3

The internal energy of a system increased by 982 J when it was supplied with 492 J of energy as heat.
How much work was done?
I got that work done was 490J but the book answer is 9.0 x 10^2J.
by Maggie Doan 1I
Wed Jan 30, 2019 6:54 pm
Forum: Calculating Work of Expansion
Topic: 4A.3 7th edition
Replies: 2
Views: 55

4A.3 7th edition

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.
How do you calculate the change in internal energy?
by Maggie Doan 1I
Wed Jan 30, 2019 6:46 pm
Forum: Calculating Work of Expansion
Topic: 4A.3 7th Ed
Replies: 6
Views: 92

Re: 4A.3 7th Ed

Why is it -πr^2?
by Maggie Doan 1I
Mon Jan 21, 2019 5:49 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Post Assessment
Replies: 1
Views: 59

Post Assessment

Determine the shift in equilibrium, if any, which will occur for the following reactions when the temperature is increased a) Photosynthesis: 6 CO2 (g) + 6 H2O (l) ⇌ C6H12O6(s) + 6 O2 (g) delta H° = +2802 kJ.mol-1 b) The hydrolysis of ATP: ATP (aq) + H2O (l) ⇌ ADP + PO42-(aq) delta H° = -30 kJ.mol-1...
by Maggie Doan 1I
Sun Jan 20, 2019 7:17 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Post Assessment
Replies: 1
Views: 59

Post Assessment

A researcher fills a 1.00 L reaction vessel with 1.84 x 10-4 mol of BrCl gas and heats it to 500 K. At equilibrium, only 18.3 % of the BrCl gas remains. Calculate the equilibrium constant, assuming the following reaction is taking place. 2BrCl(g) ⇌ Br2 (g) + Cl2(g) I keep getting 19.8 but I know tha...
by Maggie Doan 1I
Wed Jan 16, 2019 8:34 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 7th Edition 5J.1
Replies: 3
Views: 57

7th Edition 5J.1

CO + H2O ⇌ CO2 +H2
c) If the concentration of CO is increased, what happens to the concentration of H2?
Why would H2 increase?
by Maggie Doan 1I
Wed Jan 16, 2019 8:28 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 5I.7 7th edition
Replies: 2
Views: 65

Re: 5I.7 7th edition

Thanks, I did forget to convert.
by Maggie Doan 1I
Wed Jan 16, 2019 7:34 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 5I.7 7th edition
Replies: 2
Views: 65

5I.7 7th edition

A reaction vessel of volume .500L at 700. K contains 1.20 mmol SO2, .50 mmol O2, and .10 mmol SO3. At 700 K, Kc= 1.7 x 10^6 for the equilibrium 2SO2 + O2⇌ 2SO3.
Calculate the reaction quotient Qc.
I got 6.9 x 10^-3 but the answer was 6.9.
by Maggie Doan 1I
Wed Jan 16, 2019 12:55 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.7 7th edition
Replies: 1
Views: 64

5I.7 7th edition

If Q=1.0 for the reactin N2 + O2 2NO at 25 C will the reaction have a tendency to form products or reactants, or will it be at equilibrium?

How to you find the K value of the equation?
by Maggie Doan 1I
Wed Jan 16, 2019 12:28 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Post Assessment
Replies: 1
Views: 53

Post Assessment

Write the equilibrium constant expression for the unbalanced chemical equation.
NO2 (g) + H2 (g) ⇌ NH3 (g) + H2 O (l).

Is the answer (NH3)^2/ (H2)^9(NO3)^2?
by Maggie Doan 1I
Thu Jan 10, 2019 4:33 pm
Forum: Ideal Gases
Topic: HW # 5G.5 7th edition
Replies: 2
Views: 85

HW # 5G.5 7th edition

c) Assuming that the initial pressure of X2 was .10 bar, calculate the value of K for the decomposition.
by Maggie Doan 1I
Thu Jan 10, 2019 1:01 am
Forum: Ideal Gases
Topic: Post Assessment
Replies: 3
Views: 80

Post Assessment

Why are equilibrium constants useful?
by Maggie Doan 1I
Thu Dec 06, 2018 8:01 pm
Forum: Calculating the pH of Salt Solutions
Topic: 6D.11
Replies: 1
Views: 193

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. f) Cu(NO3)2 I don't understand how f) is less than 7. Also how would you write the chemical equation to justify?
by Maggie Doan 1I
Mon Dec 03, 2018 4:57 pm
Forum: Naming
Topic: 9C.3 7th edition
Replies: 1
Views: 43

9C.3 7th edition

a)potassium hexacynidochromate (III) - the answer is K3 [Cr(CN)6] How come the formulas don't have a charge when writing from the coordination compounds and why is it K3? d)soduim bisoxaltodiaquaferrate(III) - Na[Fe(OH2)2(CO3)2] Does the order of the ligands matter because I mixed up the (CO3)2 and ...
by Maggie Doan 1I
Sun Dec 02, 2018 6:31 pm
Forum: Naming
Topic: Naming and Charges
Replies: 1
Views: 58

Naming and Charges

In lecture, there was an example of [Ni(CN)6]-2 and the name was tetracynonicelate(II). I was confused on the -ate part because I know you add the -ate if the metal has a negative charge but I thought Ni would have a positive charge.
by Maggie Doan 1I
Thu Nov 29, 2018 10:13 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Charges
Replies: 4
Views: 80

Charges

How do you find the charges of each of the elements with the complexes?
by Maggie Doan 1I
Thu Nov 29, 2018 9:48 pm
Forum: Naming
Topic: Coordination Number
Replies: 3
Views: 78

Coordination Number

How do you find out the coordination number?
by Maggie Doan 1I
Mon Nov 26, 2018 11:05 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: Ion- Ion and Dipole- Dipole
Replies: 1
Views: 34

Ion- Ion and Dipole- Dipole

How do you tell if molecules have an ion- ion force or a dipole- dipole force? Like I don't understand why HCl is dipole- dipole.
by Maggie Doan 1I
Mon Nov 26, 2018 7:32 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: Boiling Point
Replies: 3
Views: 167

Boiling Point

Rank the following in terms of increasing boiling point:
LiCl, C3H7OH, C4H8, N2

Does boiling point depend on the strength of the intermolecular force?
by Maggie Doan 1I
Sun Nov 25, 2018 11:13 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability
Replies: 3
Views: 81

Polarizability

Which one has higher polarizability?
a) Be 2+ or Li 1+
b) Mg 2+ or Be 2+

I tried using the ideas of the polarizability trend but it didn't work.
by Maggie Doan 1I
Sat Nov 24, 2018 10:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E. 18
Replies: 1
Views: 43

2E. 18

d) Draw the lewis structure, VESPR formula, molecular shape, and bond angles: N2O
Why doesn't the lewis structure for N2O have a lone pair?
by Maggie Doan 1I
Sat Nov 24, 2018 9:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.9
Replies: 1
Views: 38

2E.9

What value is expected for the ClICl bond angle?
by Maggie Doan 1I
Sat Nov 24, 2018 7:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: molecular shape vs molecular geometry
Replies: 3
Views: 51

molecular shape vs molecular geometry

What is the difference between molecular shape and geometry? Which one depends on lone pairs?
by Maggie Doan 1I
Mon Nov 12, 2018 7:30 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic Compounds 2D3
Replies: 2
Views: 68

Ionic Compounds 2D3

How do you determine which compounds have ionic bonds?
And why is BaBr2 primarily more ionic than BeBr2 and BBr3?
by Maggie Doan 1I
Mon Nov 12, 2018 2:53 am
Forum: Ionic & Covalent Bonds
Topic: Boiling Point
Replies: 3
Views: 122

Boiling Point

How do you determine which compounds have a higher boiling point such as CHCl3 and CCl4?
by Maggie Doan 1I
Sun Nov 04, 2018 5:28 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 2
Views: 84

Electron Affinity

Which has a higher electron affinity, chlorine (Cl) or Neon (Ne)?

I know that chlorine has the higher electron affinity but why?
by Maggie Doan 1I
Sun Nov 04, 2018 5:08 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 4
Views: 104

Atomic Radius

What is the effect of electrons on the size of the atom?
by Maggie Doan 1I
Fri Nov 02, 2018 5:22 pm
Forum: Quantum Numbers and The H-Atom
Topic: Test #2
Replies: 1
Views: 74

Test #2

What type of orbital with principal quantum number 4 has one more nodal plan than the 4s orbital?
by Maggie Doan 1I
Fri Nov 02, 2018 4:42 pm
Forum: Quantum Numbers and The H-Atom
Topic: Determining electrons
Replies: 3
Views: 236

Determining electrons

How do you find the possible number of electrons given by quantum numbers?

Ex: n=2, l= 1
n=4, l=0, ml=-2, ms= -1/2
by Maggie Doan 1I
Fri Oct 26, 2018 5:53 pm
Forum: Quantum Numbers and The H-Atom
Topic: Test #2
Replies: 2
Views: 92

Test #2

When writing the quantum numbers for an orbital, do you include all the values of m?
by Maggie Doan 1I
Fri Oct 26, 2018 5:36 pm
Forum: Quantum Numbers and The H-Atom
Topic: Test #2
Replies: 3
Views: 131

Test #2

What does degeneracy mean?
by Maggie Doan 1I
Mon Oct 22, 2018 10:10 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: post assessment
Replies: 1
Views: 44

post assessment

In the hydrogen atomic spectrum, what is the wavelength of light associated with the n = 2 to n = 1 electron transition?

When I worked this problem out, I got -1.22 x 10^-7 as the answer but this isn't correct.
by Maggie Doan 1I
Thu Oct 18, 2018 7:08 pm
Forum: DeBroglie Equation
Topic: post assessment #29
Replies: 2
Views: 99

post assessment #29

If a proton and an electron have the same de Broglie wavelength do they have the same speed?
by Maggie Doan 1I
Sun Oct 14, 2018 6:29 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: post assessment #40
Replies: 2
Views: 40

post assessment #40

What is the wavelength of radiation emitted by a hydrogen atom in a transition from the n = 6 to the n = 5 energy level?
by Maggie Doan 1I
Sun Oct 14, 2018 4:29 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: post assessment #28
Replies: 1
Views: 43

post assessment #28

The meter was defined in 1963 as 1,650,763.73 wavelengths of radiation emitted by krypton-86 (it has since been redefined). What is the wavelength of this krypton-86 radiation? To what region of the electromagnetic spectrum does this wavelength correspond (i.e. infrared, ultraviolet, x-ray, etc.)? W...
by Maggie Doan 1I
Sat Oct 13, 2018 6:01 pm
Forum: Photoelectric Effect
Topic: Module Question 28 Part A
Replies: 1
Views: 61

Re: Module Question 28 Part A

I used the equation Ek= 1/2mv^2 for this problem. The problem already gives you the velocity and the mass of the electron is 9.109 x 10^-31 kg (which is a constant provided in the back of the textbook). I got 1.98 x 10^-19 J as the answer.
by Maggie Doan 1I
Tue Oct 09, 2018 6:32 pm
Forum: Photoelectric Effect
Topic: post assessment
Replies: 2
Views: 89

post assessment

In a photoelectric experiment light hits a metal surface and if the energy of the ________ light is ________ enough it causes electrons to be ejected from the metal surface. A. outgoing, large B. outgoing, small C. incoming, large D. incoming, small E. None of the above I know that the first blank i...
by Maggie Doan 1I
Sat Oct 06, 2018 1:49 am
Forum: Molarity, Solutions, Dilutions
Topic: post assessment
Replies: 1
Views: 55

post assessment

5.00 g of KMnO4 is dissolved in a 150.00 mL flask of water. If 20.00 mL of this solution is removed and placed in a new 2nd 250.00 mL flask and filled with water, what is the concentration of the solution in the 2nd flask? Molar Masses: K (39.10 g/mol), Mn (54.94 g/mol), O (16.00 g/mol) Why do you u...
by Maggie Doan 1I
Sat Oct 06, 2018 1:00 am
Forum: Molarity, Solutions, Dilutions
Topic: post assessment
Replies: 1
Views: 38

post assessment

What volume of 0.0380 M KMnO4 is needed to prepare 250 mL of 1.50 x 10-3 M KMnO4?
Would you just need to set them equal to each other?
by Maggie Doan 1I
Thu Oct 04, 2018 5:30 pm
Forum: Limiting Reactant Calculations
Topic: Post Assessment 26 [ENDORSED]
Replies: 1
Views: 73

Post Assessment 26 [ENDORSED]

Based on the molar ratios in a balanced chemical equation a student expects 0.20 moles of product. If the molar mass of the product is 81 g.mol-1 what is the theoretical yield?
Do I just multiply the expected moles with the actual product? And why?
by Maggie Doan 1I
Thu Oct 04, 2018 3:45 pm
Forum: Empirical & Molecular Formulas
Topic: Problem F.1b
Replies: 3
Views: 113

Problem F.1b

My calculations for the answer were off by the hundredth decimal point. For example I calculated 78.96% when the answer is 78.90%. Would I get the answer wrong?

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