Search found 25 matches

by Hank Wang 2J
Sat Mar 12, 2016 5:29 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacity
Replies: 2
Views: 427

Re: Heat Capacity

Ethane has more freedom due to the C-C single bond vs. ethene with a C=C double bond which is more rigid. Having more freedom means a higher heat capacity.
by Hank Wang 2J
Sat Mar 12, 2016 5:25 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 2015 practice final question 5
Replies: 1
Views: 312

Re: 2015 practice final question 5

It is a concentration cell. Both the cathode and the anode contain K+ ions so when calculating Ecell, it will be zero since they have the same half reactions
by Hank Wang 2J
Mon Mar 07, 2016 1:07 pm
Forum: *Amines
Topic: Common Names of amines
Replies: 1
Views: 559

Common Names of amines

I notice in the homework question 2.44 in the organic chemistry textbook that it asked for both the IUPAC and common name of an amine. Are we expected to know the common name or just the IUPAC name?
by Hank Wang 2J
Tue Mar 01, 2016 6:12 pm
Forum: *Alkynes
Topic: Line Structures of Alkynes
Replies: 2
Views: 1330

Line Structures of Alkynes

So I noticed that the alkanes and alkenes line structures are always bent indicating a carbon, but for alkynes in the homework it is always straight. I was just wondering if it would be considered wrong to draw it like an alkane or alkene but still indicating the triple bond?
by Hank Wang 2J
Sat Feb 27, 2016 5:04 am
Forum: *Alkanes
Topic: Tert and sec common names
Replies: 1
Views: 270

Tert and sec common names

Can someone explain to me what tert and sec groups are and how to identify them? I am not sure when to use them when given an inorganic compound. And i was also wondering if it is necessary to use common names or we can just use IUPAC all the time?
by Hank Wang 2J
Sun Feb 21, 2016 11:37 am
Forum: General Rate Laws
Topic: Half-Orders
Replies: 4
Views: 630

Re: Half-Orders

What would the rate constant units be for a half order?
by Hank Wang 2J
Sun Feb 14, 2016 11:25 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Rate Constant Units
Replies: 3
Views: 2975

Rate Constant Units

Does the rate constant unit change depending on whether it is 1st, 2nd, or zero order reaction?
by Hank Wang 2J
Fri Feb 05, 2016 12:29 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.13b
Replies: 1
Views: 279

14.13b

For homework problem 13b, I was just wondering why Pt is included in the cell diagram even though it was not part of the redox reaction. Also, why is there a comma between Ce4+ and Ce3+ instead of the single bar like the other cell diagrams?
by Hank Wang 2J
Tue Jan 26, 2016 11:23 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: ΔU=0 in Isothermal Process
Replies: 1
Views: 551

ΔU=0 in Isothermal Process

I know this may sound simple but can someone explain to me why ΔU is equal to zero under conditions of constant temperature? Thanks!
by Hank Wang 2J
Wed Jan 20, 2016 2:26 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Question 7.23
Replies: 1
Views: 413

Re: Question 7.23

The formula you use is q=CΔT. since they give you q and T, just rearrange the equation to C=q/ΔT.
by Hank Wang 2J
Sun Jan 17, 2016 11:18 pm
Forum: Phase Changes & Related Calculations
Topic: 8.19 Heat Percentage
Replies: 1
Views: 411

Re: 8.19 Heat Percentage

The heat change is influenced by two terms: one to raise the copper and one to raise the water. Since you said you know how to find the heat, the heat of water is 1.30x10^2 kJ, and because the total heat is 1.45x10^2 kJ, that means water contributed to (1.30x10^2 kJ)/(1.45x10^2 kJ), or 90%.
by Hank Wang 2J
Sun Jan 17, 2016 4:00 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpy
Replies: 1
Views: 341

Re: Bond Enthalpy

Yes all equations should be balanced
by Hank Wang 2J
Sat Jan 09, 2016 10:25 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Why does liquid water have high heat capacity?
Replies: 2
Views: 11549

Re: Why does liquid water have high heat capacity?

The two hydrogen atoms share electrons in a covalent bond with the oxygen. But they are shared unevenly--that is, the bond between the hydrogen and oxygen is a polar covalent bond. The oxygen is more electronegative and is more attracted to the electrons. Because electrons are negative, the oxygen a...
by Hank Wang 2J
Tue Dec 01, 2015 1:10 pm
Forum: Bronsted Acids & Bases
Topic: Oxides and acids, bases, or amphoteric
Replies: 2
Views: 574

Re: Oxides and acids, bases, or amphoteric

There is a table in the textbook on page 469 that show which elements typically form amphoteric compounds.
by Hank Wang 2J
Sat Nov 28, 2015 10:05 pm
Forum: Bronsted Acids & Bases
Topic: Stong Acid/Base
Replies: 2
Views: 655

Stong Acid/Base

How do you determine if an acid or base is strong or not?
by Hank Wang 2J
Wed Nov 18, 2015 10:46 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: K>1
Replies: 3
Views: 551

Re: K>1

No, in the course reader there is a section that states if K>10^3, then the products are favored, and if K<10^-3, then reactants are favored. If K is between 10^-3 and 10^3, then neither reactants or products are strongly favored.
by Hank Wang 2J
Mon Nov 16, 2015 11:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: question on 11.55
Replies: 3
Views: 490

Re: question on 11.55

Question 11.55 is not a problem that we are required to do according to the course reader.
by Hank Wang 2J
Fri Nov 13, 2015 12:38 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K equilibrium
Replies: 2
Views: 394

Re: K equilibrium

The K equilibrium only changes when there is change in temperature, but does not change when there is change in concentration or pressure. K only changes with temperature because according to le chatelier's principle, chemical reactions adjust to minimize the effects of any changes. If you have an e...
by Hank Wang 2J
Tue Nov 03, 2015 6:54 pm
Forum: Hybridization
Topic: Hybridization of Lone Pair
Replies: 1
Views: 480

Re: Hybridization of Lone Pair

Yes, because when finding the hybridization of a lewis structure, the electron pair would count as an area of electron density.
by Hank Wang 2J
Tue Oct 27, 2015 5:14 pm
Forum: Lewis Structures
Topic: O3 Lewis Structure
Replies: 5
Views: 6116

Re: O3 Lewis Structure

The central oxygen cannot have more than 8 electrons
by Hank Wang 2J
Wed Oct 21, 2015 10:49 pm
Forum: Lewis Structures
Topic: Homework 3.57b
Replies: 1
Views: 296

Homework 3.57b

On 57b for chapter 3, it asks us to draw the lewis structure for a hydrogen sulfite ion. Originally, i set it up with the sulfur in the middle with 4 areas of electron density, 3 for oxygen and one for hydrogen. But when I checked the solutions manual, instead of the sulfur sharing the bond with hyd...
by Hank Wang 2J
Wed Oct 21, 2015 8:36 pm
Forum: Resonance Structures
Topic: Resonance Arrows
Replies: 3
Views: 574

Re: Resonance Arrows

I'm pretty sure you can just draw them side by side with two double sided arrows. And there is no specific order since resonance is explaining that the actual lewis structure is a combination of the three.
by Hank Wang 2J
Thu Oct 15, 2015 11:00 pm
Forum: Properties of Light
Topic: Photon Emission
Replies: 2
Views: 627

Re: Photon Emission

For number 59, you just find the energy per photon using hc/lambda and then multiply that energy by 9.8x10^20 to get the total amount of energy.
by Hank Wang 2J
Fri Oct 09, 2015 5:22 pm
Forum: Significant Figures
Topic: Answer Specificity
Replies: 2
Views: 532

Answer Specificity

For some of the homework questions, my solution and the answer in the solutions manual are off by .01. For example, I would get 4.4x10^4 and the solutions manual would give 4.3x10^4. I was just wondering if this would be considered right or wrong on a test.
by Hank Wang 2J
Fri Oct 02, 2015 12:36 pm
Forum: Properties of Electrons
Topic: Question 1.15 on homework
Replies: 11
Views: 5310

Re: Question 1.15 on homework

Why does the fact that it is in the Lyman series make n2=1?

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