CHEMISTRY COMMUNITY

E_Villavicencio 2N

I did not fully understand the reason why, but Dr. Lavelle said it was fine if we just included the ions in each part of the reaction.

E_Villavicencio 2N

If you have a substituent and a methyl in one side of the double bond (to the right for example) but on the other side (left) you just have two methyl molecules, you don't have to name it Z or E, right?

E_Villavicencio 2N

Are you sure? in my discussion we put the methylethyl first, so I'm confused

E_Villavicencio 2N

If one substituent is methylethyl and other is methyl, which one is named first?

E_Villavicencio 2N

Will the answers of quiz 2 (the actal quiz) be posted?

E_Villavicencio 2N

E_Villavicencio 2N

What is the oxidation number of oxygen when in Ozone O3? If we have it in a reaction, and we have to balance the reaction, how many electrons are transferred between O3--->O2?

E_Villavicencio 2N

When balancing some reactions, sometimes water or hydrogen is added to one of the half reactions. Can somebody explain when you add each of those?

E_Villavicencio 2N

In page 340 of the book, they cancel out the units of entropy when they are adding the quantities because it goes #of moles x Sm(of each substance), and they get a result in J/K

E_Villavicencio 2N

If we have a reaction such as 2H2O2(l)--->2H2O(l)+O2(g), is the enthalpy of the reaction expressed in kJ/mol, or just kJ? Because the solutions manual adds all the values and expresses them in kJ/mol. Doesn't the mol part cancel out? Along with this question, if we are given the enthalpy and entropy...

E_Villavicencio 2N

In the solution of this problem, we have to consider two samples of water that were mixed and obtain the change in entropy. However, when we have to use the formula delta S=nCln(T2/T1) the solution manual uses 75.3 J/K as the heat capacity of water. Can someone explain to me where that value came fr...

E_Villavicencio 2N

Yes, this happens with all the compounds. The enthalpy of reverse processes only differs in the sign. In this case, the process of vaporization (from liquid to gas) requires heat, that's why the sign is positive, whereas condensation, which is the reverse process (from gas to liquid), releases heat,...

E_Villavicencio 2N

These values come from the equipartition theorem , which is used to estimate the translational (energy due to motion through space) and rotational (energy due to the rotational motion of a molecule) contributions to the internal energy of an ideal gas. The book doesn't derive the main equation of th...

E_Villavicencio 2N

Hi Katrina! When the system does work the sign will be negative, because it is losing internal energy when it does that work. When work is being done on the system, the sign will be positive because the system is gaining energy. For example, if a system expands, it will be doing work because it is p...

E_Villavicencio 2N

This problem says: Consider the reaction 2NO2(g)<--->N2(g)+O(g). If the initial pressure of NO is 1.0 bar, and x is the equilibrium concentration of N2, what is the correct equilibrium relation? The answer is K=x^2/(1.0-2x)^2 My question was: the problem gives the pressure of one and the concentrati...

E_Villavicencio 2N

In question number 7 of Chapter 11, we are given the pictures of 4 flasks of a reaction of dissociation, and we are asked to select the flask that represents equilibrium. I see the same number of molecules and atoms in both flask 3 and flask 4. The answer says Flask 3. Why is flask 3 the one at equi...

E_Villavicencio 2N

A ligand can use its lone pairs to bond in a coordination compound. Water has two lone pairs, why can't it be a bidentate? Can somebody explain that to me please?

E_Villavicencio 2N

When we have to do a MO Diagram of a compound such as HF, where the 1s orbital from H and the 2s from F combine, how do we label the resulting molecular orbital? Do we put sigma 2s? Because the book does not label them like that, it labels them 1 sigma, 2 sigma*, 3 sigma,etc., but I don't remember w...

E_Villavicencio 2N

Yes, the equilibrium constant Kc is the same for a reaction in an specific temperature, independently of the concentrations. If the temperature changes, K is going to change. Usually if you are not given a temperature, you assume that the reaction is taking place at 25 degrees Celsius.

E_Villavicencio 2N

When a problem gives you an energy needed to break a C-C bond in kJ*mol, and asks you for the wavelength required in order to break that bond, do you need to convert that energy in J (by multiplying by 10^3) and then divide it by the Avogadro's number? I am not sure about the moles part (whether you...

E_Villavicencio 2N

Question number 93 in the book says: Below is pictured the reaction between an atom of sodium and an atom of chlorine. Identify each element and the ions formed and explain your reasoning. The picture shows the atoms A (SMALLER) and B(LARGER), and then the ions C (LARGER) and D(SMALLER) Taking into ...

E_Villavicencio 2N

The least electronegative atom goes in the center. Check how the trends in the periodic table go regarding to electronegativity, and then you put the least electronegative in the center of the Lewis Structure. The exception is Hydrogen, that one never goes in the center. Hope it helps!

E_Villavicencio 2N

Ohhhhh, now everything is clear! Thank you very much!!!! :)

E_Villavicencio 2N

I know, but what I did was to use the KE equation and then calculate the wavelenght using E=h(c/lamda)... Is that wrong?

E_Villavicencio 2N

Question #33 in the book says: The velocity of an electron that is emitted from a metallic surface by a photon is 3.6x10^3 km/s. What is the wavelenght of the ejected electron? When I started solving the problem, the first equation that came to my mind was the kinetic energy one (as the electron was...

E_Villavicencio 2N

What did one charged atom say to the other? I've got my ion you! Why was the mole of oxygen molecules excited when he walked out of the singles bar? Because he got Avogadro's number! What does the diamond say to the diamond? “Sorry, I’ve been under a lot of pressure lately” The other they I went to ...

CHEMISTRY COMMUNITY

Search found 26 matches

Re: Midterm 2016 Q3C

Substituents, naming Z or E

Re: ORDER OF SUBSTITUENTS

ORDER OF SUBSTITUENTS

Re: Quiz 2 Winter 2017

Re: Post All Chemistry Jokes Here

Oxidation number of oxygen in O3

Adding H20 AND H+

Re: Units in answer

Units in answer

Chapter 9 Problem 43

Re: Homework: Chapter 8, #67

Re: Chapter 8 Problem 31

Re: Sign Conventions

Problem 11.43

Which flask represents the reaction in equilibrium?

Why is water always a monodentate?

MO Diagram for Heteronuclear Diatomic Molecules [ENDORSED]

Re: Chemical Equilibrium constant

What to do when a Energy is given in kJ*mol-1?

QUESTION ABOUT IONIC AND ATOMIC RADII

Re: Chapter 3 #57 [ENDORSED]

Re: Question: How should I decide if I use DeBroglie Equation or the equation for Kinetic Energy?

Re: Question: How should I decide if I use DeBroglie Equation or the equation for Kinetic Energy?

Question: How should I decide if I use DeBroglie Equation or the equation for Kinetic Energy?

Chemistry Jokes :)