## Search found 17 matches

Sun Mar 19, 2017 2:27 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Question 3A of Winter 2014 Practice Final
Replies: 2
Views: 335

### Question 3A of Winter 2014 Practice Final

This question asks us to pick the chemical to build the galvanic cell. Lavelle mentions that many students make the mistake of picking copper. Why can't we pick copper? Is it because copper can't be used to build a redox half reaction?
Fri Mar 03, 2017 4:20 pm
Forum: *Cycloalkanes
Topic: Cycloalkanes
Replies: 3
Views: 452

### Cycloalkanes

In class, Lavelle said that the most common C ring structures are the 5 C rings and the 6 C rings because of stability. Are they most common because they are stable or because they are unstable?
Sun Feb 26, 2017 10:40 pm
Forum: *Electrophiles
Topic: Quiz 2 Prep
Replies: 1
Views: 287

### Quiz 2 Prep

For number 10 in quiz prep 2 in the course reader, can somebody explain to me why the answer is false? Number 11 states, "The rate constant for the reaction A->B is 25 min^-1 at 298K and 35 min^-1 at 350 K. Calculate the value of the rate constant at 770K. Give your answer in min^-1. What formu...
Fri Feb 17, 2017 4:53 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: standard molar entropy
Replies: 2
Views: 504

### standard molar entropy

I wanted to clarify on a concept I'm not 100% sure about. If temperature is 25 degrees Celsius, the molar entropy of a molecule increases with molar complexity and if the temperature is 0 degrees Celsius, the molar entropy of a molecule increases with molar mass. Is this true or is it the other way ...
Fri Feb 03, 2017 4:39 pm
Forum: Balancing Redox Reactions
Topic: Ecell properties
Replies: 2
Views: 1000

### Ecell properties

Can somebody please explain the difference between an extensive and intensive property? Also, is Ecell an extensive or intensive one? Why? Thank you :)
Tue Jan 24, 2017 7:43 pm
Forum: Calculating Work of Expansion
Topic: work
Replies: 1
Views: 197

### work

If a question asks for maximum work, why should we immediately know that we are dealing with a reversible reaction? (wmax=wrev) Can somebody please explain the concept behind this?
Fri Jan 20, 2017 5:07 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Problem 8.37 [ENDORSED]
Replies: 1
Views: 243

### Problem 8.37[ENDORSED]

The problem states, "At its boiling point,the vaporization of 0.579mol CH4(l) requires 4.76 kj of heat. What is the enthalpy of vaporization of methane?"

My question: To solve this you would divide the heat by the moles(4.76kj/0.579mol). What is the reasoning behind dividing by moles?
Thu Jan 12, 2017 6:43 pm
Forum: Phase Changes & Related Calculations
Topic: HW Problem 8.21
Replies: 1
Views: 212

### HW Problem 8.21

Problem 8.21 says, "A piece of copper of mass 20.0g at 10.0 degrees C is placed in a vessel of negligible heat capacity but containing 50.7g of water at 22.0 degrees C. Calculate the final temperature of the water. Assume no energy is lost to the surroundings." My question: I know that we ...
Sat Dec 03, 2016 1:52 am
Forum: Calculating the pH of Salt Solutions
Topic: Strength of Acids/Bases
Replies: 1
Views: 451

### Strength of Acids/Bases

Can somebody explain to me the relationship between the strength of a base or acid and the Ka/Kb and PKa/PKb? I know that the smaller the PKb of a base, the stronger the base.
Mon Nov 21, 2016 6:53 pm
Forum: Bronsted Acids & Bases
Topic: KA VS KB
Replies: 2
Views: 458

### KA VS KB

I know KA is used for weak acids and bases. However, what is the KB used for/ to find?
Mon Nov 21, 2016 6:50 pm
Forum: Lewis Acids & Bases
Topic: Acid and Bases
Replies: 1
Views: 307

### Acid and Bases

What is the difference between percentage yield, percentage ionization, and percentage deprotonation? This is for when we are checking to see if we need to use the quadratic equation or not.
Fri Nov 04, 2016 8:26 pm
Forum: Lewis Acids & Bases
Topic: Fall 2014 Midterm Question 2B
Replies: 2
Views: 427

### Fall 2014 Midterm Question 2B

In this question, it asks to draw the lewis structure for aluminum chloride and name its shape. Then, it asks if the aluminum atom is a lewis acid or lewis base. Why is the aluminum atom a lewis acid? Is it because aluminum is a cation? Therefore, the aluminum atom is positive in charge and is attra...
Fri Oct 28, 2016 4:32 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8019
Views: 1403928

### Re: Post All Chemistry Jokes Here

The name's Bond.
Ionic Bond.
Taken not shared.
Fri Oct 21, 2016 7:17 pm
Forum: Quantum Numbers and The H-Atom
Topic: Question 2.19 in textbook
Replies: 1
Views: 300

### Question 2.19 in textbook

Can somebody explain why for part b 5 values are allowed for an electron in a 6d-subshell? Do you not take into the consideration the number 6? Do you only take into consideration the d in 6d?
Fri Oct 14, 2016 4:53 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Balmer/Lyman Series [ENDORSED]
Replies: 3
Views: 567

### Re: Balmer/Lyman Series[ENDORSED]

Can somebody explain the concept of the balmer/lyman series and why the balmer series covers the visible region and the lyman series covers the ultraviolet region? Thank you. :)
Fri Oct 07, 2016 4:42 pm
Forum: Properties of Light
Topic: Problem 7 Quiz 1 Preparation in the Workbook [ENDORSED]
Replies: 1
Views: 272

### Problem 7 Quiz 1 Preparation in the Workbook[ENDORSED]

Can somebody explain to me how the final units of measurements come out to hertz? 7.If the wavelength of orange-yellow light is 6.2x10^2 nm, what is its frequency? c=wavelength*frequency frequency=c/wavelength frequency=(2.99x10^8 m*(s^-1))/(6.2x10^2 nm) frequency=(2.99x10^8 m*(s^-1))/6.2x10^-7 m)=4...
Fri Sep 30, 2016 7:27 pm
Forum: Student Social/Study Group
Topic: CHEM JOKES
Replies: 29
Views: 4346

### Re: CHEM JOKES

Chemistry jokes are sodium funny! I slapped my neon that one.