## Search found 26 matches

Thu Mar 16, 2017 10:27 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Winter 2016 Final Question 2A
Replies: 2
Views: 472

### Winter 2016 Final Question 2A

In the solution to this question there is the following part:

K = PPCL5/PPCl3PCl2 = 2x/x2

How do we get the 2x/x2? I know this is from Chem 14A, but a quick refresher would be very helpful.

Thanks in advance!
Sun Mar 12, 2017 10:29 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Chapter 15 Question 81
Replies: 1
Views: 846

### Chapter 15 Question 81

The equilibrium constant for the second-order attachment of a substrate to the active site of an enzyme was found to be 326 at 310 K. At the same temperature, the rate constant for the second-order attachment is 7.4 x 10 7 L/mol x s. What is the rate constant for the loss of unreacted substrate from...
Sun Mar 05, 2017 8:22 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Chapter 15: Question #99
Replies: 1
Views: 277

### Chapter 15: Question #99

Which of the following plots will be linear? (a) [A] against time for a reaction that is first order in A; (b) [A] against time for a reaction that is zero order in A; (c) ln[A] against time for a reaction that is first order in A; (d) 1/[A] against time for a reaction that is second order in A; (e)...
Sun Feb 26, 2017 10:23 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Chapter 15 Question 55
Replies: 1
Views: 318

### Chapter 15 Question 55

Indicate whether each of the following statements is true or false. If a statement is false, explain why. (a) For a reaction with a very large equilibrium constant, the rate constant of the forward reaction is much larger than the rate constant of the reverse reaction. (b) At equilibrium, the rate c...
Mon Feb 13, 2017 12:20 pm
Forum: Balancing Redox Reactions
Topic: Equations for reversible and irreversible processes
Replies: 1
Views: 310

### Equations for reversible and irreversible processes

Do we use the same equations for entropy, enthalpy, work, and Gibbs free energy for reversible and irreversible processes? If not, when are the equations different and what are the equations we use for each process?

Thanks in advance!
Sat Feb 11, 2017 10:26 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Winter 2013 Midterm: Question 6A [ENDORSED]
Replies: 1
Views: 400

### Winter 2013 Midterm: Question 6A[ENDORSED]

A gaseous mixture consisting of 2.23 mmol N 2 and 6.69 mmol H 2 in a 500.-mL container was heated to 600. K and allowed to reach equilibrium. Will more ammonia be formed if that equilibrium mixture is then heated to 700. K? Give a brief reason and answer. For N 2 (g) + 3H 2 (g) <---> 2NH 3 (g), K = ...
Sun Feb 05, 2017 7:59 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Chapter 14 Question #85
Replies: 1
Views: 334

### Chapter 14 Question #85

Volta discovered that when he used different metals in his “pile,” some combinations had a stronger effect than others. From that information he constructed an electromotive series. How would Volta have ordered the following metals, if he put the most strongly reducing metal first: Fe, Ag, Au, Zn, C...
Thu Jan 26, 2017 5:37 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Quiz 1 Preparation: Question 6
Replies: 4
Views: 609

### Quiz 1 Preparation: Question 6

What mass of propane, C3H8(g), must be burned to supply 2580. kJ of heat? The standard enthalpy of combustion of propane at 298. K is -2220. kJ/mol-1.

How do I go about answering this question?

Thanks in advance!
Sun Jan 22, 2017 6:24 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Chapter 8: Question #103
Replies: 3
Views: 409

### Chapter 8: Question #103

Calculate the molar kinetic energy (in joules per mole) of Kr(g) at (a) 55.85 'C and (b) 54.85 'C. (c) The difference between the answers to parts (a) and (b) is the energy per mole that it takes to raise the temperature of Kr(g) by 1.00 'C. The quantity is known as the molar heat capacity. What is ...
Mon Jan 09, 2017 2:21 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Chapter 8 #3
Replies: 1
Views: 346

### Chapter 8 #3

Air in a bicycle pump is compressed by pushing in the handle. If 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 ...
Fri Dec 02, 2016 10:31 pm
Forum: *Titrations & Titration Calculations
Topic: 2012 Final Q #7A
Replies: 1
Views: 362

### 2012 Final Q #7A

For the following two titrations predict the pH (equal to 7, above 7, or below 7) at the stoichiometric point. Also give a brief statement as to what general characteristic you would use in selecting a suitable indicator for each titration. pyridine (C 6 H 5 N) titrated with HI _____________ CH 3 CH...
Tue Nov 22, 2016 9:23 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Chapter 12 Question 19
Replies: 1
Views: 329

### Chapter 12 Question 19

12.19 The concentration of HCl in hydrochloric acid is reduced to 12% of its initial value by dilution. What is the
difference in the pH values of the two solutions?

How would I go about answering this?

Thanks in advance!
Mon Nov 21, 2016 8:47 pm
Forum: Bronsted Acids & Bases
Topic: J Section Question 1
Replies: 2
Views: 595

### J Section Question 1

Identify each compound as either a Brønsted acid or a Brønsted base:
(a) NH3;
(b) HBr;
(c) KOH;
(d) H2SO3;
(e) Ca(OH)2.

Are there any strategies to identify Brønsted acids and Brønsted bases without looking at chemical equations? Or are we just expected to memorize them?
Sun Nov 20, 2016 10:12 pm
Forum: Conjugate Acids & Bases
Topic: Chapter 12 Question 1
Replies: 3
Views: 599

### Chapter 12 Question 1

Write the formulas for the conjugate acids of
(a) CH3NH2, methylamine;
(b) NH2NH2, hydrazine;
(c) HCO3-;
and the conjugate bases of
(d) HCO3-;
(e) C6H5OH, phenol;
(f) CH3COOH.

How would I go about answering this?

Thanks in advance!
Thu Nov 10, 2016 11:13 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chapter 17 Question #33
Replies: 1
Views: 293

### Chapter 17 Question #33

Which of the following ligands can be polydentate? If the ligand can be polydentate, give the maximum number of places on the ligand that can bind simultaneously to a single metal center: (a) HN(CH 2 CH 2 NH 2 ) 2 (b) CO 3 2- (c)H 2 O (d) oxalate How would I go about answering this question? Thanks ...
Sun Nov 06, 2016 7:11 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Chapter 4 Question #107
Replies: 1
Views: 917

### Chapter 4 Question #107

What changes in bond order, bond distance, and magnetic properties are expected to occur in the following ionization processes?
(a) C2 --> C2+ + e-
(b) N2 --> N2+ + e-
(c) O2 --> O2++e-
Sat Oct 29, 2016 10:12 pm
Forum: Hybridization
Topic: Chapter 4 Question #81
Replies: 1
Views: 538

### Chapter 4 Question #81

Borazine, B3N3H6, a compound that has been called “inorganic benzene” because of its similar hexagonal structure (but with alternating B and N atoms in place of C atoms), is the basis of a large class of boron–nitrogen compounds. Write its Lewis structure and predict the composition of the hybrid or...
Tue Oct 18, 2016 12:53 am
Forum: Formal Charge and Oxidation Numbers
Topic: Chapter 3 HW #23
Replies: 1
Views: 405

### Chapter 3 HW #23

Chlorine can exist in both positive and negative oxidation states. What is the maximum (a) positive and (b) negative oxidation number that chlorine can have? (c) Write the electron configuration for each of these states. (d) Explain how you arrived at these values. May someone explain how to answer ...
Tue Oct 18, 2016 12:48 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Chapter 2 HW: #39 [ENDORSED]
Replies: 8
Views: 2184

### Re: Chapter 2 HW: #39[ENDORSED]

Thank you to everyone who replied. This cleared things up.
Sun Oct 16, 2016 3:08 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Chapter 2 HW: #39 [ENDORSED]
Replies: 8
Views: 2184

### Chapter 2 HW: #39[ENDORSED]

Determine whether each of the following electron configurations represents the ground state or an excited state of the atom given.

I do not know how to go about this. May someone explain how to answer this question?

Thank you!
Sun Oct 09, 2016 8:11 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Quiz 1 Preparation: Fall 2014 Question #10 [ENDORSED]
Replies: 6
Views: 901

### Quiz 1 Preparation: Fall 2014 Question #10[ENDORSED]

An excited hydrogen atom emits light with a frequency of 1.14 x 10 ^14 Hz to reach the energy level for which n = 4. In what principle quantum level did the electron begin?

May someone explain to me how to work this problem out step by step?

Thank you!
Tue Oct 04, 2016 12:54 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Question 1.43
Replies: 2
Views: 493

### Re: Question 1.43

Yes, that helped a lot! Thank you!
Mon Oct 03, 2016 10:56 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Question 1.43
Replies: 2
Views: 493

### Question 1.43

The problem reads: What is the minimum uncertainty in the speed of an electron confined to within a lead atom of diameter 350. pm? Model the atom as a one-dimensional box with length equal to the diameter of the actual atom. I looked at the solutions manual and h is being solved for. I am confused b...
Mon Oct 03, 2016 10:47 pm
Forum: Molarity, Solutions, Dilutions
Topic: Help on G.19.
Replies: 2
Views: 673

### Re: Help on G.19.

Hi Alex! This helped so much. Thank you!
Sat Oct 01, 2016 11:31 pm
Forum: Molarity, Solutions, Dilutions
Topic: Help on G.19.
Replies: 2
Views: 673

### Help on G.19.

The question reads: (a) A sample of 1.345 M K2SO4(aq) of volume 12.56 mL is diluted to 250.0 mL. What is the molar concentration of K2SO4 in the diluted solution? (b) A sample of 0.366 M HCl(aq) of volume 25.00 mL is drawn from a reagent bottle with a pipet. The sample is transferred to a flask of v...
Wed Sep 28, 2016 12:23 am
Forum: Student Social/Study Group
Topic: Sproul Hall Chem14A Study Group
Replies: 30
Views: 2835

### Re: Sproul Hall Chem14A Study Group

I also live in Sproul Hall. What time and days are you meeting?

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