CHEMISTRY COMMUNITY

Lauren Worley 3C

: Neo vs Tert

A picture of the differences between tert- and neo- is attached!

Lauren Worley 3C

The correct answer of problem 5 on the practice quiz is said to be:

3-bromo-1-iodocyclohexane

Why is it not 1-bromo-3-iodocyclohexane?

Is there a numbering rule for halides that specifies which halides get priority to the lower number?

Lauren Worley 3C

The question asks if the activation energy of the reaction in 125kJ/mol, will it occur at room temperature. I understand that that is a high activation energy and that heat needs to be added so that the reaction can occur. What I am unsure of is what value of an activation energy would be low enough...

Lauren Worley 3C

For a zero value reaction use the graph of [A] vs. time k=slope
For a first order reaction use the graph of ln[A] vs. time k=slope
For a second order reaction use the graph of 1/[A] vs time. k=slope

Time is always on the x-axis

Lauren Worley 3C

For question 6A in the practice midterm we are given a combustion reaction which must be balanced to find the change in Gibbs free energy to determine whether or not the process will be spontaneous. The answers balanced the given equation like so: 2AlCl3(g)+9/2O2--->Al2O3(s)+6ClO(g) Why is it okay t...

Lauren Worley 3C

You can use either bond enthalpies or enthalpies of formation to find delta H to use in the Gibbs free energy equation. Using both bond enthalpies and enthalpies of formation will give you the same delta H value. But when using bond enthalpies use the equation: sum reactant bond enthalpies - sum of ...

Lauren Worley 3C

I was wondering the same thing. I think because it asked for delta G of the balanced reaction you must use whole number coefficients. I believe it is only appropriate to use fractional coefficients when it asks for the delta G of formation of a compound because we specifically want to find the value...

Lauren Worley 3C

Why do we assume that delta Svap and delta Hvap are the same at 258K as the delta Svap and delta Hvap at the actual boiling point (239.7K) when solving for delta G (in problem 9.53)

Don't you have to calculate a different entropy of vaporization at 258K like in example 9.6 (p 329 of the book?)

Lauren Worley 3C

You are correct that the reaction does release energy and that it would make sense for it to be negative. It is just the way the question was written--calculate its enthalpy density and how much enthalpy is released per liter -- that signals for us to write the enthalpy that we solve for as a positi...

Lauren Worley 3C

Why does using the bond enthalpies to solve for the enthalpy of formation of a compound give you the enthalpy of formation of the gaseous state of the compound ? For example: on problem 67, when using the bond enthalpies of H2O, benzene, and methanol, you end up with the enthalpy of formation of the...

Lauren Worley 3C

The smaller the metal cation is and the greater the charge it has, the stronger acid it will be.

Lauren Worley 3C

The problem is just asking how many electrons can have these quantum numbers. For the first example the quantum numbers n=3 and l=1 correspond to the 3p subshell. There can be a total of 6 electrons in the 3p subshell because there are three orbitals within the subshell that can hold 2 electrons eac...

Lauren Worley 3C

For part b: Also it is important to note that there is a one to one ratio of H3O+ and HCLO4 because HCLO4 is a strong acid and dissociates pretty much completely in water. That is why you can use the initial concentration of HCLO4 as the concentration of H3O+ in the solution.

Lauren Worley 3C

The partial pressures were given in kPa. Because 100kPa=1bar, the partial pressures given were converted to bar by diving by 100. Bar is the pressure unit that should be used when finding Kp.

Lauren Worley 3C

The book gives us the decomposition equation of X2(g)=2X(g) At equilibrium the mole fraction of X2 is 5/17 and the fraction of X is 12/17 We are also given that the initial pressure of X2 is 0.1bar In the answer book, to find the partial pressures of X and X2 at equilibrium the mole fraction and ini...

Lauren Worley 3C

Yes, you have to double the radius for the uncertainty of the position because the absolute furthest the electron could be from its predicted location is the length of the diameter of the molecule.

Lauren Worley 3C

Bond order correlates to both bond length and strength. A higher bond order means that the bonding is shorter and stronger.

Lauren Worley 3C

Nitrogen can lose an electron to another atom in the same molecule when the element it is bonded to has a higher electronegativity (higher ability to attract electrons). So often oxygen "takes" an electron from nitrogen bc it has a higher electronegativity. Nitrogen can also lose an electr...

Lauren Worley 3C

Chlorine monoxide is a radical meaning that it has an unpaired electron. In the Lewis structure I put the unpaired electron electron on the oxygen so that the formal charges on chlorine and oxygen would equal zero. In the answer key the unpaired electron is on the chlorine atom. Why is that? Wouldn'...

Lauren Worley 3C

The easiest way to do this problem is first by observing that n 1 for the Balmer series is always 2 (n 1 =2). They gave the wavelengths of the first four lines in the spectrum which have n 2 values of n 2 =3, 4, 5, 6. (You can check this by seeing if you get the provided wavelengths when you plug th...

Lauren Worley 3C

The mole part of the KJ/mol is important. This unit would make the work function mean the energy required to eject an entire mole of electrons. Kinetic energy of an ejected electron = Energy photon – Work Function ^^This equation focuses on only one electron and one photon. Therefore, we only want t...

CHEMISTRY COMMUNITY

Search found 21 matches

Re: Tert vs. Neo

Naming cycloalkanes with halides: practice quiz question 5

Organic Chem. Book: Q 4.30 Activation Energy and temperature

Re: Graphical Method to solve for k?

Winter 2012 Midterm Question 6- free energy of combustion

Re: Bond Enthalpies

Re: Workbook Quiz 1. #9

delta G of vaporization not at boiling point: 9.53

Re: Problem 8.51

Using bond enthalpies to solve for enthalpy of formation.

Re: Cations as Acids

Re: Final 2012 Q3A

Re: Calculating a pH from a Concentration

Re: 11.89 Calculating the Equilibrium Constant

Equilibrium Partial Pressure: Question 11.7

Re: Uncertainty in position

Re: Bond Order Correlation

Re: Nitrogen Bonding

Homework Problem 3.59: CLO lewis structure

Re: Finding n values in Rydberg

Re: Post Module Assessment Question