Search found 30 matches

by Christine_Mavilian_3E
Wed Mar 15, 2017 7:26 pm
Forum: *Alkenes
Topic: Question 2.47 in the Organic Chemistry Textbook
Replies: 1
Views: 638

Re: Question 2.47 in the Organic Chemistry Textbook

If I am correct, alkenes and alkynes are both considered functional groups in terms of their double and triple bonds . Take for instance the alkene group. It is comprised of two carbon atoms joined together by a double bond. Other attachments around the carbon atoms can involve H or R bonds with the...
by Christine_Mavilian_3E
Sun Mar 12, 2017 4:54 pm
Forum: *Carboxylic Acids
Topic: Carbonyl
Replies: 1
Views: 594

Re: Carbonyl

A carboxyl functional group is a carbonyl plus an alcohol (functional group). A carbonyl functional group has a double bonded oxygen to a carbon atom that can be either bonded by one or two hydrogen atoms or two carbon atoms (aldehydes and ketones). A carbonyl group is not the same things as saying ...
by Christine_Mavilian_3E
Fri Mar 10, 2017 1:31 pm
Forum: *Electrophiles
Topic: Nucleophile vs Electrophile
Replies: 5
Views: 1275

Re: Nucleophile vs Electrophile

Generally speaking, you can identify whether something is a nucleophile or electrophile simply when the molecule is by itself. For instance, Cl- is a nucleophile while neutral Cl is an electrophile. However, if you combine molecules to form a compound, the compound can be a nucleophile or electrophi...
by Christine_Mavilian_3E
Fri Mar 03, 2017 5:34 pm
Forum: *Cycloalkanes
Topic: Cycloalkanes
Replies: 3
Views: 446

Re: Cycloalkanes

Five C rings and six C rings are the most common ring structures because they are stable.

I hope this helps!
by Christine_Mavilian_3E
Thu Mar 02, 2017 10:21 am
Forum: *Nucleophiles
Topic: Ambient Nucleophiles
Replies: 1
Views: 403

Re: Ambient Nucleophiles

Ambident Nucleophiles are nucleophiles that can act as an electron source via different atoms because they have lone pairs located on different atoms. This is best seen in compounds that contain resonance such as Thiocyanate (SCN^-). The best way to approach a problem like this is to draw out your L...
by Christine_Mavilian_3E
Thu Feb 23, 2017 6:29 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Method of Initial Rates: Course Reader Question
Replies: 1
Views: 317

Re: Method of Initial Rates: Course Reader Question

Based on what I gather from your question, in order to determine how the initial rate depends on [NO2-], you would have to calculate the order (n, m, variable used does not really matter) by using two experiments from a given data set. In order to do this you would use experiments one and two becaus...
by Christine_Mavilian_3E
Tue Feb 14, 2017 6:05 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Sig Fig Rules (Hess's Law)
Replies: 2
Views: 1493

Re: Sig Fig Rules (Hess's Law)

Regardless of whether you are flipping the equation and/or multiplying and dividing numbers to get your "desired" reaction, the significant figures in your final answer ( which would be the sum of your enthalpies) would depend on the lowest number of decimal places in the values you are ad...
by Christine_Mavilian_3E
Wed Feb 08, 2017 4:43 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: What is N?
Replies: 1
Views: 290

Re: What is N?

By finding the value of n, we are able to determine the order of the reaction (i.e. first order, 2nd order, etc.). This in turn helps us determine the reaction mechanism, which are the number of steps taken to form the product(s). We haven't gone into too much detail regarding reaction mechanisms ye...
by Christine_Mavilian_3E
Tue Feb 07, 2017 5:07 pm
Forum: General Science Questions
Topic: quiz 1
Replies: 3
Views: 700

Re: quiz 1

No, he does not drop the lowest quiz score. He announced during lecture that for this quiz, units and significant figures will not be taken into consideration in the overall score.
by Christine_Mavilian_3E
Fri Feb 03, 2017 5:45 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: As i goes to zero...?
Replies: 1
Views: 240

Re: As i goes to zero...?

From what I recall during lecture, the i represents the current in the limit that approaches zero.

I hope this helps!
by Christine_Mavilian_3E
Mon Jan 30, 2017 6:07 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: HW 8.49
Replies: 1
Views: 243

Re: HW 8.49

I'm not sure if this is the answer you were looking for, but in order to solve problem 49 we need to use the ideal gas equation PV=nRT. In order to do this calculation we need to assume constant conditions where the temperature at standard conditions would be 25 degrees Celsius which equals to 298K....
by Christine_Mavilian_3E
Wed Jan 25, 2017 11:16 am
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Question 31(b
Replies: 1
Views: 333

Re: Question 31(b

Although I am not 100% certain that this is the correct answer, I would say that the cause of a greater entropy in one structure versus the other is due to the bond angles (its formation), and the types of bonds (i.e. single, double, and triple) that are present in the molecule. Cyclopentane (C5H10)...
by Christine_Mavilian_3E
Fri Jan 20, 2017 6:26 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Entropy Relationship [ENDORSED]
Replies: 2
Views: 427

Re: Entropy Relationship [ENDORSED]

Enthalpy is the amount of heat absorbed/released at a constant pressure. Internal Energy is the sum of all potential and kinetic energy in a system. Entropy is the degree of randomness or disorder. We know that Delta U (change in internal energy) is a state property and the change is a function of i...
by Christine_Mavilian_3E
Fri Jan 20, 2017 5:44 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Work of Expansion [ENDORSED]
Replies: 2
Views: 431

Re: Work of Expansion [ENDORSED]

If I correctly understand your question, based on the lecture today, there was an example with a diagram where the system (ideal gas) was expanding to twice its volume. The mass would slowly decrease and the system would expand slowly, doing more work. During such process it will lose energy but it'...
by Christine_Mavilian_3E
Fri Jan 13, 2017 9:13 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Most Stable Form
Replies: 4
Views: 1131

Re: Most Stable Form

If I am correct, in this case, it's not necessary to draw out the Lewis structure with a formal charge of zero in order to determine a molecule's most stable form. In the course reader, it mentions that most reactions are given in their standard state. In most instances, it would be simple to determ...
by Christine_Mavilian_3E
Thu Dec 01, 2016 11:48 pm
Forum: Lewis Acids & Bases
Topic: Homework problem 12.23
Replies: 1
Views: 366

Re: Homework problem 12.23

Kw is equal to the concentration of your hydronium ion times the concentration of your hydroxide ion. In other words Kw = Ka times Kb. In the problem you've been give the value of your Kw which is 2.1x10^-14. Set this value equal to Ka and Kb (where 2.1x10^-14=Ka x Kb) and substitute those for x val...
by Christine_Mavilian_3E
Tue Nov 22, 2016 7:56 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic and Endothermic
Replies: 4
Views: 924

Re: Exothermic and Endothermic

If the reaction requires heat (endothermic reaction) to form more products, then the reaction will shift to the right favoring more product formation. If the reaction gives off heat (exothermic reaction) while forming product, then the reaction will shift to the left favoring reactant formation. I h...
by Christine_Mavilian_3E
Wed Nov 16, 2016 7:38 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Concentration and Pressure
Replies: 1
Views: 288

Re: Concentration and Pressure

Kc is calculated given the concentration of the products and the reactants. Kp is also an equilibrium constant like Kc. However, Kp is calculated given the pressure values of the products and the reactants. Typically the question will ask you to calculate the Kp or Kc, however, if they don't mention...
by Christine_Mavilian_3E
Thu Nov 10, 2016 3:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Ideal gas law
Replies: 2
Views: 344

Re: Ideal gas law

Here is what each variable in the Ideal Gas Law (PV=nRT) stands for: P = pressure V= volume n= moles R= Gas constant T=temperature With respect to temperature, the units must always be in K (Kelvin). Convert to Kelvin if a given temperature in the problem is not in Kelvin. With respect to your gas c...
by Christine_Mavilian_3E
Thu Nov 10, 2016 3:40 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Lecture question
Replies: 1
Views: 248

Re: Lecture question

In the course reader, it mentions that we calculate the Reaction Quotient (Q) to determine which direction a reaction will proceed. It also says that you can calculate the reaction quotient at any time during the reaction and compare it to the Equilibrium Constant K. Typically in a problem, the valu...
by Christine_Mavilian_3E
Thu Nov 10, 2016 3:11 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: QUIZ 3
Replies: 2
Views: 417

Re: QUIZ 3

If I am not mistaken, we need to know the Molecular Orbital Theory and how to draw the diagram for the quiz; I don't know if we will be tested on actually writing the valence electron configuration, but it doesn't hurt to know how to do it and you can figure it out from the diagram. I hope this helps!
by Christine_Mavilian_3E
Thu Nov 03, 2016 5:09 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Homework 4.51 - Molecular Orbital-Level Diagrams
Replies: 1
Views: 366

Re: Homework 4.51 - Molecular Orbital-Level Diagrams

We know that in this molecule we have two atoms of Lithium that are bonded together. Each Lithium atom has a 2s, so when we combine them we have a sigma 2s bonding orbital, and a sigma 2s antibonding orbital ( this is indicated by the asterisk/star). Each lithium atom has one valence electron (becau...
by Christine_Mavilian_3E
Sat Oct 29, 2016 11:03 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Memorization Tips
Replies: 3
Views: 607

Re: Memorization Tips

Based off of my study method, I would say that the one of the best ways to learn the VSEPR models is to learn the symbols (for instance AX4E, AX4E2) and the shapes they correspond with. By learning these symbols you can figure out what the compound would look because, for example, the AX4 part would...
by Christine_Mavilian_3E
Thu Oct 27, 2016 4:23 pm
Forum: Lewis Structures
Topic: Formal Charge vs Octet Rule
Replies: 3
Views: 1188

Re: Formal Charge vs Octet Rule

Formal charge takes precedence over the Octet Rule in terms of structure stability. Simply put, the Octet Rule only indicates that an element must have eight electrons to achieve a filled valence shell/ noble gas configuration ( there are those rare instances where some elements don't need 8, an exa...
by Christine_Mavilian_3E
Wed Oct 19, 2016 7:20 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Chapter 2 Question 2.43 [ENDORSED]
Replies: 2
Views: 438

Re: Chapter 2 Question 2.43 [ENDORSED]

The answer to Silver is [Kr] 4d^105s^1 instead of 4d^9, because in this case the 4d state has slightly less energy than the 5s state. Thus, you would want a more stable electron configuration, one whereby lower energy levels have their orbitals completely filled. In order to do this (achieve a stabl...
by Christine_Mavilian_3E
Thu Oct 13, 2016 5:29 pm
Forum: Empirical & Molecular Formulas
Topic: Workbook Self Test Problem 4
Replies: 2
Views: 374

Re: Workbook Self Test Problem 4

You would need to use 19.00 g/mol instead of 2(19.00 g/mol) because you're calculating the Empirical Formula of a new compound. F2 in this case is a reactant. You have to treat the reactants in their elemental state (i.e. just F) because you are not given the compound, you are empirically calculatin...
by Christine_Mavilian_3E
Thu Oct 13, 2016 3:17 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Textbook Question 2.37 part b [ENDORSED]
Replies: 3
Views: 573

Re: Textbook Question 2.37 part b [ENDORSED]

The statement is true because the s-orbital is situated more closely to the nucleus of the atom than p, d, and f orbitals. As a result, the inner electrons that are situated in the s-orbital shield outer electrons from the electrostatic attraction of the positively charged nucleus. In regards to you...
by Christine_Mavilian_3E
Tue Oct 04, 2016 4:00 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Chapter 1 Question #15 [ENDORSED]
Replies: 1
Views: 435

Re: Chapter 1 Question #15 [ENDORSED]

Your first step in calculating the frequency of the wave was correct. However, you do not use E=h*v to solve for the energy difference. In class we learned that the formula to calculate the change in energy levels is E (sub n)=(- hR)/n^2 where h represents Planck's constant of 6.626x10^-34 J.s., R r...
by Christine_Mavilian_3E
Sat Oct 01, 2016 8:12 pm
Forum: Properties of Light
Topic: calculating wavelength [ENDORSED]
Replies: 3
Views: 551

Re: calculating wavelength [ENDORSED]

For problems involving constants and or conversion values that aren't "well known", the information will most likely be provided either on a formula sheet or within the question. If you have the Periodic Table of Elements that was given with the course reader, most of these values (i.e. co...
by Christine_Mavilian_3E
Mon Sep 26, 2016 9:17 pm
Forum: Photoelectric Effect
Topic: Intensity
Replies: 5
Views: 613

Re: Intensity

If light had only wavelike properties, then the statement would be true, because increasing or decreasing the intensity would indeed affect the number of ejected electrons. However, through experimental observation, the statement is not correct as evidence of the Photoelectric Effect show that light...

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